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ENGINEERING GEOLOGY SPECIALIST GROUP

PAPERS, SERIES NO. 2

MAY 1982

ISSN 0728-7224

ENGINEERING GEOLOGY SPECIALIST GROUP PAPERS, SERIES NO, 2 MAY 1982

ISSN 0728-7224

ACKNOWLEDGEMENT These papers have been printed thanks to the generous support given by the companies and organisations listed in the Directory of Sponsors.

CONTENTS Page

ENGINEERING GEOLOGY SPECIALIST GROUP

THE APPLICATION OF ELECTROMAGNETIC PROFILING DURING ROUTE INVESTIGATIONS FOR THE TARONG POWER STATION PIPELINE, QUEENSLAND G.J. Mules

HYDROGEOLOGICAL AND HYDROGEOCHEMICAL STUDIES IN THE UPPER MAGELA CREEK CATCHMENT AREA, ALLIGATOR RIVERS REGION, NORTHERN TERRITORY M. Ahmad and H. Qureshi

SAMPLE PRETREATMENT AS AN INDICATOR OF MATERIAL PERFORMANCE R.B. Smith

PROPERTIES OF QUEENSLAND AGGREGATES J.E. Martin

DIRECTORY OF SPONSORS

ENGINEERING GEOLOGY SPECIALIST GROUP The Engineering Geology Group was established in 1979 as one of the various Specialist Groups within the Geological Society of Australia; its foundation meeting took place on 8th March 1979. The aims of the Group are to promote engineering geology in the widest sense, including environmental and urban geology, hydrogeology, geology of quarried materials, geology of coastal processes, and geology as applied to civil engineering or mining engineering and related disciplines. To achieve these aims, the Group organises meetings for the presentation of papers, field excursions, and technical sessions at the Australian Geological Conventions. This publication follows the Series No. 1 of papers published in January 1980, and contains a collection of papers presented at the 5th Australian Geological Convention in August 1981 in Perth.

ENGINEERING GEOLOGY SPECIALIST GROUP OFFICE BEARERS 1981-83 Chairman

Dr G.W. Hofmann

Secretary

Mr I.D. Hair

Treasurer

Mr J.E. Martin

Committee Members

Mr D.J. Aubrey Mr D.E. Davidson

State Representatives

- Australian Capital Territory

Dr E.K. Carter

- New South Wales

Mr E.J. Minty Mr R.B. Smith

- Northern Territory

Mr H. Qureshi

- Queensland

Mr A.L. Davies

- South Australia

Mr M. Cobb

- Tasmania

Mr B. Weldon

- Victoria

Mr J. Brumley

- Western Australia

Mr C.A. Key

THE APPLICATION OF ELECTROMAGNETIC PROFILING DURING ROUTE INVESTIGATIONS FOR THE TARONG POWER STATION PIPELINE, QUEENSLAND

G.J. Mules*

ABSTRACT A continuo us trench, 2 to 3 rn deep and 96 km long, is required to bury a pipeline for the supply of water from Boondoorna Darn to the Tarong Power Station near Nanango . Undulati ng terrain of weathere d granitic , metamor phic and sedimen tary rocks, with alluvia l deposits of sand and black clayey soil, is to be traverse d. The geologi cal investig ation commenced in 1979 with a continuo us electro magnetic (conduc tivity) profile of the first 14 km using a hand-he ld Geonics EM 31. To this test section were also applied continuo us 12 channel refracti on seismic , surface mapping , auger drilling , excavato r ·trenchin g and resistiv ity sounding s in an attempt to develop an understa nding of EM response to geologi cal conditio ns. The EM 31 was chosen for its speed and ease of data process ing, and useful applicat ion at shallow depths. The test section correla tion of electro- magneti c profiles was success fully applied to the remainde r of the line, enabling a more efficien t programm ing of detailed investig ations at a conside rable saving of time and cost. The correlat ion between EM response and investig ated conditio ns was good, allowing a greater degree of certaint y between sample points. The applicat ion of the techniqu e was success ful, and future investig ations may be improved further in the light of experien ce gained. INTRODUCTION The geologi cal investig ation of the Tarong pipeline route was commenced in January 1979 by the Queensla nd Water Resource s Commis sion's Enginee ring Geology Section . The route is 96 km long from Boondoorna Darn near Preston to the Tarong Power Station at Nanango (Fig. 1). Investig ations comprise d *

Mr Mules is a geologi st with the Enginee ring Geology Section of the Queensla nd Water Resource s Commiss ion, Brisban e. The paper was presente d at the 5th Australi an Geologi cal Convent ion, Perth, August 1981.

geological mapping and sampling, and a geophysical programme undertaken by the Geological Survey of Queensland. The aim of the investigation was to indicate surface and subsurface conditions to assist in design, excavation, and placing of the pipeline. The l 085 mm steel pipe is to be buried 2 m deep, on average, with deeper sections at gully crossings. Three pump -stations are to be constructed along with associated balancing storages and surge tanks. Specific design requirements of the investigation were (a)

indicate general surface and subsurface conditions along the route, looking at trench wall stability and backfill suitability

(b)

locate areas where excavation to 0.3 m below pipe invert might require blasting of hard rock

(c)

indicate the likely subsurface conductivities to assist corrosion protection design

The investigation team had 2 years in which to collect th~ field data and report to designers for construction tender documents. The design continued parallel to the investigation with data being progressively channelled to the engineer. A companion investigation looking at foundation materials of the route and sources of construction material for the pipeline and balancing storages was undertaken by the Commission's Materials Testing Laboratory. To achieve the design requirements in the time allowed, it was obvious that geophysical exploration was needed. The geophysicist advised against continuous shallow seismic refraction on the grounds of the considerable time and manpower required. Instead, the rapid and less expensive electromagnetic (conductivity) method was recommended, using a Geonics EM 31 for a continuous traverse along the route. The EM 31 profiling located areas of shallow rock, which then became targets for further investigation techniques such as shallow seismic refraction, trenching and sampling. In this manner, it was necessary to cover only 33 per cent of the line with expensive seismic work but still satisfy the designers that all sections of near-surface rock had been defined. The value of a continuous electromagnetic profile in planning cathodic protection of the steel pipe was also recognized. The results provided an early overview of the electrical nature of the terrains and highlighted areas of special concern. An early decision on the overall approach to protection, whether to use a sacrificial anode or an impressed current technique, was possible. Standard assessment techniques might have taken many months for the collation of relevant data, and even then the results would be discontinuous. For the aspects of investigation and design planning, the EM 31 work produced early, interpretable results and reduced field time overall. The investigator had quantitative information which, with some interpretation, could be presented to the designer at an early stage for the purposes of discussion and illustration. REGIONAL SETTING

Geology Geologically, the area is dominated by the deeply weathered granitic rocks of the Boondooma Igneous Complex and the strongly lateritised Main Range Volcanics. Undifferentiated metamorphics and sediments are faulted against

the Boondooma Igneous Complex between Proston and Gordonb rook Dam (Fig. 1). To the south, the coal-bea ring sedimen ts of the Tarong Beds overlie the Marongh i Creek Volcani cs. Other units in the area comprise the Wigton Adarnel lite, Taromeo Tonalite and the volcanic Aranbang a Beds. Quatern ary alluvium has been deposite d by the major streams in the area. A summari sed descrip tion of major rock types along the route is presente d in Table 1. Terrain A division of the route into differen t terrains of general ly uniform nature was possible . Closely related to the geology , the terrain division were defined and subdivid ed on the basis of the followin g criteria : (a) (b)

uniform ity of geomorp hology, topograp hy and vegetati on uniform ity of rock or soil type

(c)

occurren ce of outcropp ing rock

(d)

the expected degree of difficu lty of excavati on and placing the pipeline , includin g trench diggabi lity and stabilit y, access to bedding sands and suitabi lity of excavate d materia l for use as backfil l.

Five division s (based on the regiona l geology) and ten subdivis ions (based on above criteria ) were recognis ed, namely: 1.

BOONDOOMA IGNEOUS COMPLEX

1 a 1 b 1 c 1 d

Rhyolite dykes intrudin g weathere d granites Weathere d granite Weathere d granite with scattere d outcrop Weathere d granite with lateriti sed patches

UNDIFFERENTIATED METAMORPHICS

2 a

Quartzi te and schist with pegmati te dykes

QUATERNARY ALLUVIUM

3 a 3 b

Clayey sand Clay

TARONG BEDS

4 a 4 b

Conglom erate Sandston e

MAIN RANGE VOLCANICS

5 a

Laterite soil

INVESTIGATION METHODS Programme The initial investig ation used geologi cal mapping from air photos and ground traverse s, continuo us electrom agnetic profilin g (EM 31), and selected seismic and resistiv ity soundin gs. This was followed by test trenchin g and sampling . The trenchin g programme was designed ( a)

to test diggabi lity and stabilit y of materia l for correla tion with geophys ical data

(b)

to obtain a log and sample of the sub-stra ta, and to record location s of groundw ater infiltra tion.

(c)

.,,., I I

('\.

' '

......... ~

I I

'' '

Nanango

raman ,!!_w__'!~-

RONG OWERi TATlql'.J \

I I I

LEGEND

BOONDOOMA IGNEOUS COMPLEX

Allu"1um

Granodlorlta, granlla , adamallita ,gabbro, dlorite

MAIN RANGE VOLCANICS

Baaalt ,

dolerlt • ,minor ahale,altl 11 one ,diatomlt e

T AAONG BEDS

T AAOMEO TONALITE WIGTON ADAMELLITE

Sandatona,ahala,c oal,conglomar ate

Quartz-mica achlat , melaquartllte ,ahale silt a tone,gre v w ac k • ,mudatone ,c hart ,baa le amphibolite ,me I a ba aa It, mat a a gglom er ate , meta- ande ■ It a ,phylllta

ARANBANGA BEDS Faull

MARONGHI CAEEK VOLCANICS

Road

Railway

Qaologlcal Boundary

CompllaUon baaed on •Auatralla 1:2ao.ooo Oaologlcal 8arleI, Oympta• by the Oaologlcal Surway of Ouaanaland.

KILOMETRES 0

REGIONAL GEOLOGY

Fig. 1

TABLE 1 DESCRIPTION OF MAJOR ROCK TYPES

Formation

BOONIXX>MA

IGNEOUS COOPLEX

Rock Type

Composition

Texture

Macro Structure

Mode of Occurrence

FRESH GRANODlORITE, ADAMELLITE 10.5 km83.5 km (scattered}

QUARTZ FELDSPARS MICAS

Med.-coarse grained, even, crystalline interlockin g, massive

Massive, widely spaced blocky jointed. Joint spacing 100 rnm5 m

Outcrops as large rounded boulders with thin weathered surface layer. Deep soil profile grading from weathered rock to bedrock

WEATHERED GRANODIORITE, ADAMELLITE, RESIDUAL SOILS 1.5 km 83.5 km

QUARTZ FELDSPARS CLAY MINERALS (PROBABLY KAOLINITE} MICAS

Evenly weathered, coarse grained, clayey sands to clay, friable to stiff plastic

Horizons - silty top soil to clayey sand or clay, to decomposed 'granite' to mod. weath. rock

Residual soils over granitic bedrock, exposed in gullies and road cuttings

RHYOLITE DYKES 1.5 km 10.5 km

QUARTZ FELDSPARS VOLCANIC GLASS

Med.-v. fine grained crystalline and glassy, flow banded, massive or brecciated

Lineations and banding, dense blocky jointing. Joint spacing 10-500 mm

Narrow ridges of slightly weathered, fractured rock with clay coated, Fe std. joints and thin soil development . Loose surface fragments or outcrop

TABLE 1 (continued)

Formation

Rock Type

Composition

Texture

Macro Structure

Mode of Occurrence

SCHIST QUARTZITE, 16.2 km 19.7 km

QUARTZ MICA FELDSPARS CLAY MINERALS

Fine grained, developed schistosity, banded

Steep-dipping cleavage and jointed. Joint spacing 20-200 mm

Outcropping on narrow ridges and hillocks, elsewhere covered by rocky residual soils

19 km and 33.5 km

QUARTZ FELDSPARS MICAS

V. coarse grained, even, interlocking · crystaliine texture, massive

Steep dipping, blocky joints. Joint spacing 50-100 mm

Narrow dyke swarms form ridges, loose cobbles and boulders on surface. Little soil cover. Associated with contact between granites and metamorphics

CONGLOMERATE 86.6 km 92.5 km

ROCK FRAGMENTS SANDY MATRIX LABILE CF..MENT

Coarse grained, poorly sorted, rounded phenoclasts. Variable grain size and composition

Massive lensoid, interbedded with sandstones

Rarely outcropping (road cuttings). Weathered rock below thin gravelly soil. Rounded ridges

SANDSTONE 92.5 km 96 km

QUARTZ GRAINS LABILE CEMENT MINOR PEBBLES

Fine-medium grained, poorly sorted, weakly cemented, local induration

Poorly bedded and jointed, lensoid, interbedded with conglomerates

Minor outcrop on ridges, sandy soil cover on undulating hills

BASALT 84.5 km

FELDSPARS PYROXENES OLIVINE

Fine grained, even, crystalline, massive. Some phenocrysts

Blocky jointed

Boulder outcrop (rare on route). Deep lateritic soil cover. Non-laterised has deep bouldery clay soil cover. Elevated plateaux or rldges

33. 5 km &

UNDIFFERENTIATED METAMORPHICS

84 km

PEGMATITE

TARONG BEDS

MAIN RANGE VOLCANICS

Excavat ion was carried out with equipme nt likely to be used in constru ction. The collecte d data were presente d in a series of drawings at 1:25 000 showing sequent ially (a) the geologi cal plan, (b) the electro- magneti c profile , and (c) the longitud inal section with seismic , electric al and trenchin g informa tion (Figs 2, 3 and 4). Each drawing presente d 1.5 km of line, and a 10 to 1 vertica l exagger ation in section was necessar y to facilita te present ation of shallow trench data. The aim of this style of present ation was (a)

to match the layout and scale of design and constru ction drawing s

(b)

to present all collecte d informa tion on one drawing for ease of comparis on and interpre tation. The constru ction enginee r would be encourag ed to use the data to assist accurate estimati ng and competi tive contrac ting

(c)

to be useful as a constru ction drawing for both supervis or and contrac tor alike

Special drawing s were prepared for creek and gully crossing s to show surface geology and seismic secti.o ns. Equipme nt The seismic refracti on programme was accompl ished with a Nimbus ES-1210 , a twelve-c hannel signal enhancem ent seismog raph. Using a normal 12 geophone spread length of 60 m (5 m geophone interval ) and shot points every 15 m, the field crew of 4 complete d the work in 72 days. This included 30.38 km of profilin g along the line and 4.J km at various stream crossing s . . Resistiv ity was necessar y to assist the interpre tation of the EM 31 and 105 vertica l electric al sounding s were made. Using a Geotest DIO 2 DC bridge compens ator in an expanded Schlumb erger electrod e configu ration, the results allowed the geophys icist to determin e the layer which contribu ted most to EM 31 response , thus permitti ng a less ambiguou s interpre tation of the electrom agnetic data (Nunn and Huber, 1981). Trenchin g was undertak en in two stages with a Kato 1100G and a Himac Hm-690 excavat or. A total of 248 trenches were dug, 57 of these resisted excavati on while 20 were unstable or potente ntially unstable . Sampling and testing were carried out as part of the materia ls investig ation. Tests on soils included visual descrip tion, sieve analysi s, determi nation of Atterber g limits, and some in-situ moisture measure ments. EM 31 Operatio n The Geonics EM 31 was chosen to carry out the electrom agnetic profilin g because of its speed and ease of data process ing. With a station interva l of 5 m, two technici ans accompl ished a 93 km coverage in 30 days. The instrume nt is easily carried by one person who can record the data with the aid of a small tape recorder or notebook . The princip le of operatio n of the EM 31 is simple. A transmi tter coil located at one end of the instrume nt induces circular eddy current loops in the earth. Under certain conditio ns, fulfille d in the design of the EM 31, the magnitud e of any one of these current loops is directly proport ional to the terrain conduct ivity in the vicinity of that loop. Each one of the current loops generate s a magnetic field which is proport ional to the value of the current flowing within that loop. A part

of the magnetic field from each loop is intercepted by the receiver coil and results in an output voltage which is therefore also linearly related to the terrain conductivity (Geonics Limited, 1978). EM 31 profiling gives a continuous read-out of near-surface conductivity (averaging to depths of about 6 m). In an ideal near-surface situation, less weathered rocks have lower conductivities than more weathered rocks or unconsolidated sediments. Other factors, which may affect conductivities, are clay content in soils, moisture content and salinity and, to a lesser degree, rock type. Fresh rock at shallow depth, dry, loose sand and freshwater all tend to reduce near-surface conductivities. Higher EM 31 values could be expected over deep residual soils and clayey alluvium. These generalisations may become ambiguous at times due to the masking effect of thin layers with markedly different conductivities to the average subsurface condition. The unit of measurement of conductivity is millimhos/m or millisiemens/m (metric), and along the pipeline, readings ranged from 2 to 182 millisiemens/m. The EM 31 has an intercoil spacing of 3.66 m and a boom length of 4.0 m. It weighs 9 kg and disassembles for storage to a length of 1.4 m. Power is supplied by 8 'size C' alkaline cells, and readings are facilitated by a dial-type meter with a range of 0-1, 3, 10, 30, 100 or 300 millisiemens/m. The conductivity reading divided into 1000 gives resistivity in ohm-m and measurements can be made with an expected accuracy of! 5 per cent (at 20 millisiemens/m). INTERPRETATION AND APPLICATION OF RESULTS Investigation At the commencement of the investigation, the application of this method of electromagnetic profiling to engineering projects was in its infancy. The only available data were sketchy outlines of projects reported on by the manufacturer and presented with the operations manual , (Geonics Limited, 1978). Since then, more information has been made available by Geonics Limited, with particular reference to the more recently developed EM 34-3, which has the capability of measuring at depths from 7.5 m to 60 m (McNeill, 1980). Considering this lack of information, it was necessary to establish a framework for interpreting EM response with specific application to the Tarong pipeline. Continuous EM 31 and shallow refraction seismic profiles were conducted over the first 14 km of route. This was followed by surface mapping and trenching. The data were quickly processed and assessed to facilitate an on-going field programme in which time was the essence. Typical results are shown in Figures 2 and 3, which indicate how the EM 31 responded to variation in subsurface conditions. Fresh rock at or near the surface has a conductivity between O and 20 millisiemens/m; results in Figure 2 at 3.5 to 4.5 km show this relationship. Deep soil cover 9n weathered rock (granite) has a high conductivity, generally greater than 40 millisiemens/m as can be seen in Figure 3 at 7.5 to 8.5 km. Plastic clays produce a sharp contrast and high conductivities as at 3.3 km in Figure 2.

ELECT RO - MAGN ETIC PROFILES q,~

Rhyollte ' \ ~ I Clay bouldern 0 _7 w..e.AtJiered 4<6 rhy~11ta9 2300

320

310

300

300 1800

290

280'---------------'---------

3km

3 .5km

------------------280

4km

4.5km

LONGITUDINAL SECTION Vertical Scale

1 O: 1

LEGEND

D [IIITII]

RHYOLIT E, Apllte SAND SILT CLAVEY SAND SIL TY SAND

EXPLANA TORY LOOS

Geologica l descripti on

BOULOER Y SILT

Realatlvl ty :

ffES a1100

Outcrop :

::::·

Drift :

,,'

Jo i nt Spacing :

Jt . Sp.

GEOPHY SICS LEGEND

•

~r' \

Seismic inuitydiscont

1100

r!f::~t'~r

Clay Weethered

4 _5 rhyollle

/ \ Depth ~t•f~~uae l strata continuin g

velocity, ~ BOULDER Y SAND Seismic mean (m/a)\ -

,.. I

'\~

/Wuther ed " I 3.1 / _ granite

Trench :

Fig. 2

ow ve 1oc It y layer

3km - 4.5km

100

.....

80 80 40

ELECTRO - MAGNETIC PROFILES EL

"J" "J

33!5 330

thered g ~ r a n l t e t."-

320

770

~ 81

"J . 4. 1

~!. nlt~olla v · 3 o 1000

300

320

Weather e d gran it e

'\'\

u_J~

~"J':, "3 300 950 1820 103 20 O 2~--"Je,~• 0 3000 ~ ~;1//2300 2880 Cemented san Sand and clayey sand Weathered granite 3 _1 Decomposed granite 310 2180

310

290 ' - - - - - - - - - - - - - . . . . J - - - - - - - - - - - - - - - ' - - - - - - - - - - - - - - - ' 2 9 0

7 .5km

9km

8 .5km

8km

LONGITUDINAL SECTION Vertical Scale

10: 1

LEGEND Trench : RHYOLITE, Apllte

EXPLANATORY LOGS

~ GRANITE, Pegmatlte ~ ~ CLAYEY SAND /

C:.::::::J

L-±.1 BOULDERY SAND

'\-4.

Weathered! granite 3.1

Geological description

11BT

Outcrop : Drift :

Clay We the re d 4 _5 rtyo ll te

\, / Depth Depth strata continu ing at refusal

GEOPHYSICS LEGEND Seismic velocity , mean (m/a)\ 5

~r'\

Seismic discontinu ity•

•

Seismic retractor

1100

• ow velocity layer

7 .5km - 9km Fig . 3

12 The close correlation between EM data and 'seen' physical conditions lent much confidence to the continued application of the technique to the remainder of the route. Analysis of the test to 14 km allowed us to develop a preliminary rule-of-thumb by which further investigations could be planned. Initially, the following criteria were established EM values less than 10 millisiemens/m - fresh rock at or close to the surface could be expected and such sections required further detailed investigation. EM values greater than 40 millisiemens/m - a deep soil profile was expected and investigation required only confirmatio·n of this. Very high readings with s harp contrast were interpreted to be due to the presence of hig h plasticity clays. EM values between 10 and 40 millisiemens/m - conditions were suspect and required more investigation. This simplification became very useful in early planning and offered the design and geotechnical engineers a basis for understanding shallow subsurface conditions. From the EM data, and available geological information, it was possible to 'see' sections of apparently consistent nature for which a trenching programme could be planned to obtain representative sections of subsurface soil and rock conditions along the 96 km route. Following a similar line, the geophysicists were looking at the results of resistivity soundings made within the first 14 km. Comparing these to EM 31 data, it was possible to determine which layer was giving the predominant response to the measured average conductivity. Accordingly, a refined and more technically based rule-of -thumb was developed for the purpose of planning seismic programmes. The geophysicists found that resistivity soundings showed that the first layer was usually thin (about 1 m or less) and of higher resistivity than the second layer. The second layer (or third layer, if the second is also thin) generally gave the predominant contribution to the EM 31 response. Where the first layer was thin and resistive, the following rules-of-thumb were developed: When EM 31 conductivity is greater than 40 millisiemens/m and second layer resistivity less than 20 ohm-m (greater than SO millisiemens/m), then 'hard' bedrock was 'deep' and no follow-up seismic work is required. When EM 31 conductivity is less than 30 millisiemens and second layer resistivity greater than 40 ohm-m (less than 25 millisiemens/m), then 'hard' bedrock was probably 'shallow' and follow-up seismic work is required. When EM 31 conductivity is between 10 and 40 millisiemens/m and second layer resistivity between 20 and 40 ohm-m (50-25 millisiemens/m), then the case is marginal. Other geological, trenching or drilling evidence was used to assist the interpretation, and seismic work was usually carried out (Nunn and Huber, 1981). A typical example of applying this rule-of-thumb can be seen in Figure 4, where there is little surface indication of subsurface conditions. Here the second layer, or in this case the third, has a resistivity of 65 ohm-m and conductivities are grouped into two ranges (a) 10-30 millisiemens/m and (b) 30-70 millisiemens/m. Applying the rule-of-thumb we could expect fresher rock close to the surface in group (a) but deeper in group (b).

13 Seismic velocities greater than 1500 m/sec generally suggest fresher rock but trenching had often refusal depths in material with velocities between 1700 m/sec and 2000 m/sec. With this approach to interpreting the EM 31 data and planning investigations, it was possible to limit the seismic coverage to 52 per cent but still maintain continuity of information. In this way the investigation was able to satisfy design requirements with a considerable saving in cost and time. Overall, an average seismic coverage of 33 per cent was achieved of which the first 14 km had 100 per cent coverage, 14 km to 37 km 50 per cent coverage, and 37 km to 96 km only 7 per cent coverage. Construction If the EM 31 data are to be of maximum value they mustbeof use not only to the design investigators but also to the construction engineers. If the conductivity plots are presented in conjunction with surface geology and subsurface data, their significance is easily comprehended and they become a valuable contribution to the prediction of construction conditions. Such predictions are essential to accurate estimating and competitive contracting. To this end, the continuous EM 31 data can provide a link between individual sample points (trenching, resistivity and seismic profiles). Consistent EM 31 response between points suggests consistent subsurface conditions. If surface geology data support this assumption, then results at sample points become more reliable as a representation of subsurface conditions between sample points. An example of how this logic might be applied is shown in Figure 5. Here the low EM 31 response is seen to be due to high velocity rock (2000 m/sec) near the surface. Seismic data are incomplete, but a massive aplite outcrop to the right of the pipeline suggests that near-surface rock might be extensive. In estimating what length of this section might require blasting for excavation the contractor is assisted by the continuous EM 31 plot: he could expect hard rock conditions to continue some 80 m beyond the seismic traverse with improvement toward the end of the section where EM 31 values increase. SUMMARY In developing an approach to the application of the EM 31 to shallow engineering problems, experience on the Tarong pipeline recognises some basic procedures: Establish a model to explain EM response over varying terrain. 1. 2.

Relate this response to the particular geological or engineering parameter being investigated, whether it be diggability, clay content, parent rock type, potential stability, or any other.

Assign broad limits or classifications to that relationship, i.e. develop rules-of-thumb. Apply those rules to define targets for further investigations.

Ensure that such application has a built-in check to guard against broad terrain changes which might not fit the model originally established. In our case, the resistivity soundings and continuing comparison or seismic and trenching data to EM response allowed checking and refinement of our original assumptions.

Present all data together to facilitate interpretation and extrapolation.

Scattered rock

fragment ■

PLAN

•

Scattered rock fragment•

► = 80

! -------•

_...

~........,,,,,,_....... ·.. , Oc 40 •·• • • g: .. . . . . ..,..... -. . ...... ..... . .~.:•' ., •....- · z .! ...,,,..,,............_..,. .....,.,. ·.. ~ _ .....,. O.! o= e

.,. o,_______________ ....._________________,,_______________~o

ELECTRO - MAGNETIC PROFILES

390

~C,.._tt, ~~

380

.._'b • _,,,,,,-1111 n•

370

-\/ 3 !o-;IWeathered granite 1750 190~ - 2100

3110

-m

3~ Clay with 8 ~ lronatone 1550 ~u~- ---'\ 86 n-m 2500 000 800

,,,

oo n-m

1000

,n~I

~ 11100 11100 ~ 10ot1e00 ,>110~ ~000 ~ 1200 11100 1.7 1000

380 370

20 00

360

350.__ _ _ _ _ _ _ _ _ _ _ _..__ _ _ _ _ _ _ _ _ _ _ _..__ _ _ _ _ _ _ _ _ _ __

31.5km

32km

32.5km

350

33km

LONGITUDINAL SECTION Vertical Scale

1 O: 1

LEGEND GRANITE, Pegmatlte

EXPLANATORY LOGS

Trench : Raalatlvlty :

CLAYEY SAND

11,r RES aftOO

Drlfl :

GEOPHYSICS LEGEND Seismic velocity, mean (m/s)\

•

~r'\

5 Seismic d i scontinuity-

Seismic retractor

1100

ow velocity layer

31.5km - 33km Fig. 4

7 ~ '

,~1

E 0

"'"' v

TARONG - Ptp~INE

' '

-- ~s

~f~-? -~ - =--:-~-~~.::.-:. ~--::·~~~ -·:~~--~:;,;t•::p-.. t •;_. .-c:''.:;. :;:;.:::::•·:,2 ;:,,, ,_,,,;, ,,

"' .j

~~~~f::~= ==~~,!J;-~-~B:~Ai~-~:fl~

--~ "'\llrt.·,:- .:--,,~--:: • :·.• :-•• _-__': ;. •

Cl•v•v aand

-;,: ,:-;;:_-;;.;,;.;,;,-..

"'"'"''""

PLAN

80 80

ROCK

N EAR S U R F A C E - - - 1

E II)

"' "'

CONDUCTIVITY

"'v

~...

!Ii: •~ w

~~~ ~~ 6~~ ~ 1... ~700

3000

2000

SECTION

1, enc h

-1:

Natural Scale

RHVOLITE, Apllte SANO

GEOPHYSIC S LEGEND Seismic velocity,

Outcrop : Shot Point

ING

CREEK CROSS dlacontinu / ~''\ o w layer velocity Selamlc lty~ ~ AT 42.07km Selamlc mean (ml•\

relractor

Fig . 5

The results of applying this approach to the Tarong pipeline route investigatio n were: (a)

considerabl e savings in time and cost by reducing the seismic refraction coverage, needed to satisfy design requirement , from 100 to 33 per cent

(b)

an early conductivit y 'map' that was found to be very useful in planning investigatio ns

(c)

continuous interpretati on between sample points with increased confidence in investigatio n results, and

(d)

actual values of conductivit ies to assist in the design of corrosion protection.

A consistent correlation of the initial interpretati on of conductivit y data with the results of more detailed investigatio ns supports strongly the suggestion that such data provide a useful indication of shallow ·subsurface conditions at an early stage of investigatio n. ACKNOWLEDGEMENTS The author wishes to ·acknowledge the permission of the Commissione r, Queensland Water Resources Commission, to use data collected during the investigatio n. The Draftsmen of the Project Planning Branch provided excellent drafting support throughout the project . •REFERENCES GEONICS LIMITED, 1978: conductivit y meter.

Operating Manual for EM 31 non-contact ing terrain

McNEILL, J.D., 1980: Electromagn etic terrain conductivit y measurement at low induction numbers. Technical Note TN-6, Geonics Ltd. NUNN, R.H., and HUBER, R.D., 1981: Geophysical surveys for the proposed Tarong pipeline. Geological Survey of Queensland, Record 1981/1 (unpublishe d).

HYDROGEOLOGICAL AND HYDROGEOCHEMICAL STUDIES IN THE UPPER MAGELA CREEK CATCHMENT AREA, ALLIGATOR RIVERS REGION, NORTHERN TERRITORY

M. Ahmad and H. Qureshi*

ABSTRACT

Hydrogeological studies suggest a two aquifer system in the upper Magela Creek area, separated by a discontinuous semi-pervious layer of extremely weathered rock. The upper aquifer consists of the unconsolidated surficial material and laterite profile. The lower aquifer is in relatively fresh fractured rock and associated carbonate-bearing horizons. Hydrochemical data suggest that most waters are a bicarbonate type, but show a change to a bicarbonate-chloride type in the areas surrounding the main surface drainage tracts. This is interpreted to be due to higher evapotranspiration. Calcium and magnesium are the dominant cations in the intake areas, but a change towards sodium and potassium predominance is noted in the discharge areas. This is interpreted to be due to cation exchange with the clay minerals. Stable isotope data suggest that waters in the upper aquifer have gone through extensive evapotranspiration,and solute concentrations in these waters can be partly attributed to this. The waters in the deeper aquifers do not show any evidence of evapotranspiration. Tritium meas~rements suggest that waters are not well mixed. The waters in the lower aquifer are older than 1954, but those in the upper aquifer have some post-1954 component . • INTRODUCTION This paper summarises the results of hydrogeological and hydrogeochemical studies in the upper Magela Creek catchment area surrounding the Ranger uranium mine. Magela Creek is a tributary of the East Alligator River and is situated some 230 km east of Darwin (Fig. 1).

* Dr Ahmad is Environmental Hydrogeologist, and Mr Qureshi is Senior Hydrogeologist, with the Water Division, Department of Transport and Works, Darwin. The paper was presented at the 5th Australian Geological Convention, Perth, August 1981.

The Alligator Rivers Region contains some of the richest and largest uranium deposits in the world, namely, Jabiluka, Ranger, Koongarra and Nabarlek, of which the first two lie in the Magela Creek catchment. Climate The climate is tropical and has two distinct seasons: (a)

The dry season, lasting from May to mid-Novemb er. During this period the temperature ranges from an average minimum of 0 20 C to an average maximum of 32 0 C. Rainfall is negligible and the sky is normally cloudless.

(b)

The wet season, lasting from mid-November to April. This is a period of heavy monsoonal rainfall, most of which falls between January and March. An average of 1 600 mm of rain falls during this season. The temperature during the wet segson ranges from an average minimum of 24°c to an average maximum of 33 c. Relative humidity is high throughout the year, but reaches its peak in the wet season with a January average of 80 per cent and a minimum of 54 per cent in July. Evaporation is also high and ranges between 2 400 mm and 2 700 mm per year.

Geology Fairly comprehensi ve studies have been made of the regional geology, geophysics and hard rock geochemistr y (Needham and Stuart-Smit h, 1980; Needham and others, 1980; Stuart-Smit h and others, 1980; Tucker and others, 1980; Ferguson and Winer, 1980). The subsurface geological details around the Ranger Mine, as extrapolate d from the geophysical and drilling results, are summarised in Figure 2. The geology is dominated by the granitic rocks of the Nanambu complex of Archean age. These rocks are medium to coarse-grain ed and have gneissic to granitic textures. They are underlain by schistose rocks of the Cahill Formation of lower Proterozoic age, which consists of a lower member, composed partly of carbonate and carbonaceou s rocks passing transitiona lly upward into a more psammitic upper member. The Cahill Formation rocks are overlain by Nourlangie schists, which are mostly quartz-mica schists. The area is largely covered by surficial material comprising sand, silt, sandy clay and lateritic gravel, and ranging in thickness from a few metres to about 50 m. The maximum cover occurs about 2 km northeast of Jabiru Airfield. There is a strip, about 2 km wide, running parallel to the Magela Creek, which has a relatively thicker cover of surficial sediments. The average thickness along this strip is probably of the order of 20 rn or more. HYDROGEOLOGY One hundred and fifty exploratory and production bores have been drilled in the upper Magela Creek area, mainly by the mining companies and the Water Division, Department of Transport and Works. The information collected from the exploratory bores, surface geophysical surveys (200 km), auger holes and excavation work for the uranium mills and tailings impoundmen ts, suggests that there are two major aquifera:

VAN DIEMEN 12°00'

GULF

-+I

12°00'

',j I-'· i.Q

C '"I (1)

t"' 0

()

0J r-'

..... IT

13°00'

r-' 0J ::i

ADELAIDE RIVER

'~' 0 0 0

i<)

0 0 0

100 Kilometre

~ t-' \.0

Figure 2.

Subsurface geological map of upper Magela Creek area

21 (a)

Upper aquifer consisting of unconsolidated surficial sediments and lateritic profile,

(b)

Lower aquifer consisting of relatively fresh, fractured rock with carbonate horizons.

The two aquifer systems are separated by a semipervious zone comprising weathered rock. The upper aquifer is generally unconfined, but the presence of clay horizons in some areas has rendered the aquifer as semi-confined in places. The results of pumping tests show that the transmissivity for the upper aquifer ranges between 1 and 90 m2/day, and the yield from Oto 6 L/sec. The lower aquifer is semi-confined. In areas where the weathered (decomposed) rock horizon is either lac~ing or thin, it may be unconfined. Transmissivity ranges between 9 and 126 m /day. Groundwater supplies show a range where yields up to 20 L/sec can be obtained from the carbonate horizons in the lower Cahill Formation. In general, supplies from the schistose rocks are poor, but pegrnatoid bodies and gneissic rocks have moderate to high yields. Drilling has recorded open fractures to a depth exceeding 100 m, but the actual bottom of the aquifer would in general lie above that depth. Recharge to the aquifer systems is by infiltration of rainfall via overlying lateritic soils. There are areas with a relatively high recharge capacity. The water table is at its lowest level in September-October at the end of the dry season. With the onset of the wet season, water levels rise more or less abruptly reaching their peaks towards the end of February. Seasonal fluctuations in groundwater levels of 3 to 5 mare common. Water table contours for September 1980, i.e. when the water levels were lowest,are shown in Figure 3. It can be seen that groundwater level contours approximately follow the topography. The water level contour map shows that the groundwater movement trend is towards the north. The water level contour map also suggests that the same groundwater is discharging into Magela Creek and its tributaries. The map further suggests that the elevated areas are recharge areas while the lower areas are discharge areas. HYDROGEOCHEMISTRY The chemistry of groundwaters from the upper Magela Creek area is summarised in Table 1. The excellence of groundwater quality is apparent from this table. The saturation indices for calcite, dolomite, gypsum and magnesite have been calculated, and results suggest that most waters are grossly unsaturated with respect to these minerals with the exception of a few samples ·from the carbonate horizons in the Cahill Formation, where ·saturation with respect to calcite and dolomite has occurred. The bedrock lithologies are dominated by muscovite, feldspar, biotite, chlorite and quartz. These minerals are metastable and break down to an assemblage containing kaolinite, montmorillonite, microcline, low albite and amorphous silica in near surface conditions. In order to correlate water composition with the lithology these have been plotted on a aMg++/a(H+) 2 vs. aSiO 2 diagram (Figure 4). This plot suggests that groundwaters are in equilibrium with an assemblage containing montmorillonite, kaolinite, amorphous silica± chloride and carbonates.

Figure 3.

Water level contour map for September 1980

o'.

TABLE 1 CHEMICAL COMPOSITION OF GROUNDWATERS UPPER MAGELA AREA RANGE S,D, MEAN 5,6 - 8,7 7.27 0.71 22 - 440 209.34 107,66 5 - 204 95,31 53,55 10 - 320 154,06 74.99 2 - 40 9,57 8.07 2 - 33 11.60 8.45 1 - 31 14,52 13,34 1 - 20 3,91 3,86 9 - 250 107.86 64,88 1 - 21 4.07 • 3,87 3 - 24 9.17 9.15 0,1 - 1 0,25 0.17 1 - 3 0.89 0,59 0,1 - 25 2.67 5.93 1 - 107 46,88 29,88 0,01 - 5.2 0,76 1.11 0.04 - 55 4.29 11,91 0,1 - 6Q 12.13 16.55 0,1 - 11 2.41 5,67 0,5 - 4.3 1.32 1.11

ELEMENT/ ION PH CONDUCTIVITY ALKALINITY T.D.S. Ca Mg Na K

HC03 S04 Cl

F tW 3

Fe S.i.02

NO. OF ANALYSES 67 66 62 65 73 73 73 73 71 72 72 44 62 61 48 24 26 23 18 18

Cu Pb · zn

u Ra NOTES:

3. 4, 5,

CONDUCTIVITY IS GIVEN IN µSIEMENS/CM CU, PB, ZN AND U ARE GIVEN IN µG/L RA IS GIVEN IN P CUR ·IE/L ALL OTHER ELEMENTS, IONS, ALKALINITY AND TOTAL DISSOLVED SOLIDS ARE GIVEN IN MG/L ,,. . . s ~D, STANDS FOR STANDARD DEVIATION I

16,-------....--------------

12 N

+ I

I-

■

NANAMSU SCHIS TS & GNEISSES

+o,

LOWER

CAHILL CARBONATES

LOWER

CAHI LL

•

SURFICIAL

SED IME NTS

* I I

0 ....J

•

SCHISTS

GIBBS I TE

IK AOLIN ITE I

QUAR TZ SATUR ATION

I I :

I AMORPHO US SILI CA SATURATIO N-, I

-6

-5

-4

-3

-2

-1

Log a( H4 Si04 )

Figure 4.

Diagram with mineral stability boundaries and water composition from different types of lithologies . Thermodynamic data from Helgeson (1969)

The spatial distribution of hydrochemical facies is shown in Figure 5. Groundwaters in the lower Cahill carbonate-bearing horizon are Mg-Ca-Hco 3 type and are clearly influenced by rock lithology. Groundwaters in the surficial sediments close to the Magela Creek channel are Cl-Hco or Cl 3 type. This is a low-lying discharge area with near-surface water table conditions. The high chloride concentrations in this area may be attributed to higher rates of evapotranspiration. In other places, the dominant anion is bicarbonate but the relative predominance of various cations changes. In the intake areas, most waters are Ca-Mg-HCO 3 type, while the discharge area waters are predominantly Na-K-HCO 3 type. From intake to discharge area, the following variations in hydrochemical facies are observed: Ca-Mg-HCO 3 + Mg-Ca-Na-K-HCO 3 + Na-K-Mg-Ca-HCO 3 type. It has already been shown that groundwaters are in equilibrium with montmorillonitic and kaolinitic clays. It is suggested that progressive cation exchange by clay minerals is probably the main cause in hydrochemical facies changes. The following model is proposed. Dissolution of carbonates in the intake area in the presence of high partial pressures of co 2 gives Ca-Mg-HCO 3 types of waters. Some distance from the intake area, Ca and Mg are partly exchanged by clay minerals giving rise to predominantly Mg-Ca-Na-K-HCO types of water. Further away, both Mg and Ca are progres·sively exchanged lor Na and K and the water chemistry changes to Na-K-Mg-Ca-HCO3 types. Near the discharge channels, most Ca and Mg is replaced by Na and K resulting in Na-K-HCO 3 types of water. STABLE ISOTOPE STUDIES Samples of rain water, surface water, and of shallow and deep aquifers were analysed for hydrogen and oxygen isotopes by Dr. D.C. Green of the University of Tasmania. The results are plotted in Figure 6. The stable isotope data apparently suggest that some waters in the upper aquifer have undergone substantial evapotranspiration. Waters from the lower aquifer do not show effects of evapotranspiration and these waters lie close to the meteoric water line. Samples from surface water bodies show normal enrichment in heavy isotopes due to evaporation. The oxygen isotope results are plotted against conductivity in Figure 6. • This figure suggests that solute concentrations in the shallow aquifers can partly be attributed to evapotranspiration. Waters from the deep aquifer, however, do not define a trend and these waters may have acquired their solute contents partly through water-rock interaction. Further studies are currently in progress and their results will be given in a separate paper, TRITIUM MEASUREMENTS The Atomic Energy Commission has been measuring tritium concentrations regularly in Darwin's rain water since 1970. Groundwater samples from the Magela Creek area were analysed by Dr. Airey of the A.E.C. on behalf of the Water Division. The results are shown in Figure 7. Tritium levels in Darwin's rain water have declined from 14 T.U. in 1970 to 4 T.U. in 1980. Data given by Gat (1980) suggest that tritium levels in the tropics were highest during 1963 due to thermonuclear tests, reaching as high as 200 T.U.

Figure 5.

Map showing spatial distribution o f hydrochemical facies

■ □□

..,

/ +10

"lj

.....

i.Q

C H (1)

-9

- 10

-8

-7

-5

-3

•ss

O'I

(1)

::,

i.Q

(1)

'O Ill >: 'O ..... '< ::, 3: C/l

Ill

i.Q

C: H

Ill

(1)

::,

Rain Shallow bores Deep bores Surface waters

••

- 10

I-' Ill

Ill

(') H

n ::r

(1)

(1) Ill 0 (1) rt i.Q ;,;- (1) (1)

::,

Ill Ill rt ::,

I-'·

::,-

(1)

H 'O

c: n

S°Do/ /oo SMOW

C/l

n o. o 3 I.O 0

::, 0

.....

::, Ill 0. (') H :( 0 n> Ill 3 Ill rt 'O (1) 0 H H,

·so

C/l

.. . rt

I-'•

0 3

0 ::,

rt 0

::,(1)

-70

_8()

l'\.J -.J

__1.llJiL .

DARWIN RAIN

TRITIUM MAGELA

ANALYSES CREE K ARE A

__ _73___ _

:l: 7 :J

;:::

~ 6

--- ~~ - - - - Surfa c e ___ ]', ____ Water

-- •7-5 --- Mudg1nbem _.. 7L.. ~'.1~0.~':19. hollow . -11~7.9 __

Aquifer

20418 Mi.ed Shallow and Deep Aquifer

___ 80 __ __

~924·~.:-.:-_ -- 20385 _

9331

__20383 __ __ 975 4 _ 20365 -

Deep Aquifer 9722- 9247

o_ _ _ _..._______1,_,_ _ _ _ _ _ _ _..16,l_;..,1 ;~~m;.-:l,nm

Figure 7.

Tritium measurements of rain, surface water and groundwater. Note that the numbers for Darwin rain refer to years

Tritium levels in pre-1954 rain could be taken to be close to about 5 T.U. If pre-1954 waters infiltrated into the groundwater and thus became isolated from further effects of nuclear releases, the present-day tritium levels in the groundwater would have decreased to about 1 T.U. by 1981. However, if infiltration occurred in 1963 the levels would have been reduced to about 72 T.U. The data shown in Figure 7 then suggest that:(1) the deeper waters are older than 1954 (2)

the groundwaters are not well mixed

The absence of tritium levels which could be matched with the 1963 thermonuclear events could be due to

29 {a)

very poor infiltration to the lower aquifer

{b)

fast flow rat~s in the upper aquifer resulting in short duration flushing

{c)

a very large reservoir of older groundwater to which only small quantities of younger water are added annually

If the infiltration rates to the lower aquifer are very low, as is suggested by the tritium data, then effects of uranium mining and milling in the region on the groundwater in the lower aquifer will not be detected in the near future. Possibility {b) above is of great significance to environmental monitoring, but definite conclusions can not be reached at this stage. Possibility {c) is unlikely as the success rate in obtaining groundwater in substantial quantities is rather poor. Groundwater in the lower aquifer occurs in fractures in rocks that are otherwise quite impervious. Nevertheless, if the groundwater reservoir is very large and the infiltration rate poor, the pollutants will be substantially diluted. Further work is currently in progress to positively decide between the possibilities mentioned above. ACKNOWLEDGEMENTS We are indebted to R. Morrison, Director Water Division, Department of Transport and Works, Northern Territory for his permission to publish this paper. Thanks are due to Dr. P. Airey of the Atomic Energy Commission for supplying the tritium measurements, and to Dr. D.C. Green of the University of Tasmania for supplying the stable isotope measurements. Acknowledgement is also given to J. Paul, Principal Environmental Engineer and J. Milne, Principal Hydrologist for their assistance. REFERENCES FERGUSON, J., and WINER, P., 1980: Pine Creek Geosyncline, statistical treatment of whole rock chemical data. Int. Uranium Symposium on the Pine Creek Geosyncline. GAT, J.R., 1980: The isotopes of hydrogen and oxygen in precipitation. In Fritz, P., and Fontes, J.C. {editors) Handbook of Environmental Isotopes Geochemistry. Elsevier Publishing Company, Amsterdam. HELGESON, H.G., 1969: Thermodynamics of hydrothermal systems at elevated . temperatures and pressures. American Journal of Science, 267. NEEDHAM, R.S., and STUART-SMITH, P.G., 1980: Geology of the Alligator Rivers uranium field. Int. Uranium Symposium on the Pine Creek Geosyncline. NEEDHAM, R.S., CRICK, I.H., and STUART-SMITH, P.G., 1980: Regional geology of the Pine Creek Geosyncline. Int. Uranium Symposium on the Pine Creek Geosyncline. STUART-SMITH, P.G., WILLS, K., CRICK, I.H., and NEEDHAM, R.S., 1980: Evaluation of the Pine Creek Geosyncline. Int. Uranium Symposium on the Pine Creek Geosyncline. TUCKER, D.H., STUART, D.C., HONE, I.G., and SAMPATH, N., 1980: The characteristics and interpretation of regional gravity, magnetic and radiometric surveys in the Pine Creek Geosyncline. Int. Uranium Symposium on the Pine Creek Geosyncline.

SAMPLE PRETREATMENT AS AN INDICATOR OF MATERIAL PERFORMANCE

R.B. Smith*

INTRODUCTION The application and interpretation of soil and gravel test results by the Department of Main Roads, New South Wales is based on the assumption that the sample tested is in a condition similar to that of the material finally compacted on the road (Department of Main Roads, 1960). To this end, a variety of methods of pretreatment may be used. These methods have been briefly described by Smith (1980) and are outlined in the Appendix. It is important that the correct method of pretreatment be utilised. This paper details three cases where various methods of pretreatment have been compared. CASE l - Wilcannia When the Barrier Highway west of Wilcannia was reconstructed in 1969, material from shallow surface deposits was used as base. One such deposit was in the Dolo Hills, approximately 60 km west of Wilcannia. The geology of the hills is complex and consists of sedimentary rocks of the Upper Devonian Mulga Downs Group, which overlies Proterozoic rocks. The latter are largely obscured by the Quaternary residual and colluvial sediments (Department of Mines, 1965; Packham, 1969). Silicified materials such as grey billy and duricrust of Tertiary age also occur. The deposits themselves consisted of concretionary limestone (kunkar) nodules in a sandy-loam matrix together with fragments of soft white lithic sandstone and silicified siltstone. Selected subgrade and sub-base materials consisted of clay-loam and sandy loam, respectively, from roadside pits up to 1 m deep. Initial testing of the material proposed for base was carried out in late 1968. Preliminary testing indicated that the material would conform to the specification requirements for base. Testing up to the stage of

* Mr Smith is Scientific Officer with the Department of Main Roads, Sydney. The paper was presented at the 5th Australian Geological Convention, Perth, August 1981.

spreading on the road continued to indicate that the material quality was satisfactory. After the incorporation of water using a pulvi-mixer, and compaction using smooth drum vibrating rollers and pneumatic tyred rollers, the material was again tested. At this stage, the material was found to be outside the specification requirements because of high plasticity indices. Results of testing at each of the phases are given in Table I. As can be seen from Table I, the material after compaction was significantly finer and more plastic than before compaction. This indicated that the material could fail in service. There was, however, no evidence of pavement failure at the time the investigation took place. An investigation was carried out to determine the cause of breakdown. Two phases of the investigation are described here. Details of the initial testing phase and details of an investigation carried out on the adjacent section of pavement were presented by Smith (1980). Weathering tests were also carried out using two samples, which were divided: one portion of each sample was tested in the routine manner, and the other portion was pretreated by artificial weathering prior to testing. As can be seen in Table II, the material after weathering still conformed to the specification requirements, but the coefficient of variation due to the two tests showed significant differences. The liquid and plastic limits after pretreatment were lower than those of the two portions prepared in the normal way. The reason for this difference would appear to be that in the weathering procedure breakdown was restricted to the larger particles, which broke down to form sand size particles which in turn led to a reduction in plastic and liquid limits. The final phase involved pretreating the sample by repeated compaction, · and testing a portion of the same after 1, 2, 3 and 7 compaction cycles. All mixing was done by hand. This was followed by 15 minutes mechanical mixing using the mixer with the planetary action. Two samples were tested and showed a trend similar to that for sample C in Table III. The material became gradually finer on the 425 micron and 75 micron sieves and there was a gradual increase in the liquid limit. After the 7 cycles and 15 minutes mechanical mixing there was a significant increase in the fine portions, a significant increase in the liquid limit, and a significant decrease in the plastic limit. It appeared then that compaction itself was not causing all of the breakdown. It was concluded from this that the particular material was being abraded during mixing using the pulvi-mixer rather than during compaction. As the compacted section was not showing any signs of failure, it was sealed unstabilised. The remainder of the material had been spread but not compacted. The properties of the material were similar to those of the material in the previous sections and sand stabilisation was proposed. In this particular case, the Department's standard methods of pretreatment did indicate that there would be some breakdown during compaction but not to the extent experienced in the field. Whilst the use of the planetary mixer to abrade the particles proved harsher than was the case in the field, it did show that the material was susceptible to breakdown during construction. Testing showed conclusively that changes occurred in material properties during winning, spreading and compacting. The standard deviations indicate that the material sampled was fairly uniform and became more uniform with mixing, winning and spreading. Large standard deviations would indicate quite variable material but this was not the case. The change in

TABLE I RESULTS OF TESTING OF MATERIAL FROM THE DETAIL ED SAMPLING PHASE TO COMPACTION

Testing Phase

Detailed Sampling ( N= 10)

Stockpile Material ( N= 11)

Material After Spreading and Before Compaction ( N=31)

Material After Compaction (N .. 14)

Tl02

Large Brittle Particles Broken Down

Specification Limits M.R . Form No. 744 (Rainfall < 25Cmn)

Test Method

Pret reat me nt Mean Tl06 Retained 19mm ( %) Pass in[ 9.5mm %) Pas sing 4. 75mm ( %) Passin g 2. 36mm (%)

Standard Deviation

Mean

et,

Standard Deviation

Mean

et,

Standard Dev i ation

Mean

et,

Standard Deviation

8. 20

6.86

7.42

4.21

12 . 06

3. 73

8.07

2.95

82.20

7. 38

85.08

4. 32

82. 74

5. 59

86 .00

2.66

64 . 20

10. 32

67 .08

6.50

66.97

5. 09

72. 36

4 . 13 •

52.20

10.18

55 . 00

7.01

54 .90

6.01

°61.21

4.66 *

Tl07 Passi ng 4251Jll (l ) Passi ng 75un ( %) Less than 13 . 51Jll (%)

52 . 00

4. 57

57.33

4 . 77

55 . 10

5.30

62.00

4.08 *

26 .1 0

3.60

30. 83

4 . 00

28.45

3. 58

34.29

2.58 *

14.20

3. 77

15.42

2.02

15. 77

2. 35

20.21

1.67

T108 Li quid Li mi t

28.30

2. 95

30.83

2. 29

30.23

1. 73

31. 15

1.60

20 (max)

18. 50

1.84

18.92

1. 53

17.39

1. 26

1.17 *

15 (max)

9.80

1.87

11.83

1. 53

12 . 84

1.81

15.90 (N"' 20) 15.30 (N 20)

T109 Plastic Limit Plastici ty Index

1. 78

TllO Maximum [lry Density Opt imum Mo i st ure Co nt ent

1. 946

.029

1. 971 ( N.. 7)

. 034

1. 33

12.41

. 87

11. 71

3. 42

0. 71

1.05

0. 37

2.07

0.68 *

1. 945

.088

1. 942

0.055

13 . 10

1. 45

11.83

1. 75

T113 Linear Shrinkage

( Ns-6)

(N,-17)

(N=8 )

( %)

T va 1ue (see Oe pt Main Roads , 1960 ) NOTF: :

(N c 20)

25 (max)

all

-ve

al 1 -ve

a 11 < 6

·n, e differen ce between the rt'sults b('fore a nd after compaction is aignlflcant (P < .01). Other r e sul t s are not s l gnlfi c ant (P > . O~ ).

Res ults a re c a lcu lat ed to 2 de c ima l p la ce R [ o r st a ti s ti ca l purpos e s only.

TABLE I I

RESULTS OF MATERIAL BEFORE AND AFTER ARTIFICIAL WEATHERING

Test Method

Coefficient of Variation Due to Differences in Pretrea trnen t

Sample B

Sample A Unweathered

Weathered

Unweathered

Weathered

3. 98

82 64 51

85 70 60

88 66 54

82 65 54

3. 98 4.59 8.22

Tl07 Passing 425 µm (%) 75 µm (%) Passing Passing 13.5 µm ( %)

56 28 15

58 31 17

49 23 12

53 27 16

4.14 9.17 14.91

T108 Liquid Limit

10. 80

Tl09 Plastic Limit Plasticity Index

16 12

13.5

11. 5

12.50 9.06

Tl06 Retained 19 nm sieve (t) Passing 9.50 rrm (%) Passing 4.75 rrm (%) Passing 2.36 rrm (%)

. TABLE III RESULTS OF TESTING OF MATERIAL FROM SAMPLE C AFTER PRETREATMENT BY REPEATED COMPACTION (Tl02)

After 7 Cycles and 15 Minutes Mechanical Mixing

Tl06 Passing 9.50 nm (%) Passing 4.75 nm(%) Passing 2.36 nm(%)

86 71 62

64 54

82 67 57

68 55

69 45

Tl07 Passing 425 µm (%) Passing 75 1-.fll (%) Less than 13. 5 µn (%)

51 26 15

52 26 15

53 27 15

58 33 20

61 38 26

Tl08 Liquid Limit

Tl09 Plastic Limit Plasticity Index

17 14

17 17

15 26

Test

Number of Cycles of Compactions

•

results could not, therefore, be due to material variability in the deposit but rather to material breakdown during constructio n. Whilst pretreatmen t by repeated compaction has been shown in many cases to correlate well with field results, it d i d not in this case. In fact, the results in this instance did not indicate that the material would degrade during c_o nstruction. This points to the nE!ed not only for the samples to be pretreated but for the appropriate method of pretreatmen t to be selected. Pretreatmen t is particularl y necessary when the material is being accepted or rejected at th~ quarry and not at the work site. As a result of this investigatio n, Smith (1980) developed a simple method of pretreatmen t to be used in cases such as that described above. In this method the material is subjected to three cycles of compaction followed by five minutes mixing using a mixer with a pl anetary action. The plasticity indices and fine particle size distributio ns before compaction and mixing are compared with those after mixing and compaction. CASE 2 M.R. 503 - Putty Road, Windsor to Singleton The Department of Main Roads, New South Wales, has been investigatin g the use of shale as road base since 1935. A brief outline of the investigatio n is given by Minty and Smith (1980). As part of these investigatio ns, • research into the most appropriate method of pretreating shale was carried out from 1958 to 1961. The results of this research and the subsequent follow-up testing are described in the paper by Minty and Smith (1980). The first part of the investigatio n involved a comparison of the various methods of pretreatmen t in use at that time. Samples from nine quarries were used in the investigatio n and it was found that pr etreatment by repeated compaction best simulated field conditions. Whilst the results obtained by the method of 10 wet/dry cycles followed by repeated compactions were of similar order to those of the repeated compaction test, it was considered that the use of the former test could not be j ustified because of the time required to complete the weathering plus repeated compactions (2 weeks as opposed to less than half a day). As a result, the repeated compaction pretreatmen t has been preferred for soft rocks. Details are given in Table IV. Minty and Smith (1980) also reported on the de~ailed sampling and testing carried out on Main Road No. 503 which runs from Windsor to Singleton northwest of Sydney. Testing was carried out in 1957, 1958, 1961 and 1978. This road, which was designed for normal loading, has been subjected to increasingl y heavy loads since constructio n in 1957. The A.A.D.T. rose from 1160 vehicles per lane per day in 1969 to 1510 vehicles per lane per day in 1976. The road is a two-lane rural road with a 25 mm thick asphaltic concrete wearing surface over a base of broken shale. The annual average rainfall in the area is 819 mm at Wisemans Ferry. The same sites were used for sampling in 1958 and 1978, giving 14 pairs of data. In the intervening period, the road has only been resurfaced. Test data are shown in Table V. The test data show that the effect of weathering and traffic over the 21-year period was minimal with the material showing a significant increase in the minus 425 micron fraction and a small but significant decrease in the plastic limit. The consequent rise in the plasticity index is also small but significant . The t-test of significanc e was performed using pairs of data where the result from a site in 1958 was compared with the results from the same site in 1978. In all, 14 sites were compared. At least part

•

35 TABLE IV

Method of Pretreatment

COMPARISON OF MATERIAL PRETREATED IN THE LABORATORY WITH PRODUCT FROM THE ROAD PAVEMENT

Property

Number SIS of Cases Supporting Hypothesis that Laboratory Pretreatment simulates field Conditions

(A)

Ten cycles of wetting and drying followed by one compaction

Repeated compaction to produce material with "road gravel" particle size distribution •

Ten cycles of wetting and drying followed by a series of compactions to produce material with road gravel particle size distribution (,

Retained 19 mm sieve Passing 2.36 mm sieve Passing 475 micron sieve Plasticity Index

Data from Samples from 9 quarries (Extracted ·from Laboratory Report R68 1961).

Number (, of Cases Against Hypothesis that Laboratory Pretreatment simulates field Conditions (B) **

• 11

-29

-42

48%

72%

-38 ** X

A 100 % A+Bxl

* X

Total of Cases Supporting Hypothesis

2 2

not significant significant

65%

TABLE V COMPARISON OF SHALE PAVEMENT ON MAIN ROAD NO. 503 FOR TWENTY-ONE YEAR PERIOD 1958 TO 1978

1958 (N=l4)

Test Method (1)

°'

1978 (N=l4)

Property

t-test Mean

(4)

Standard Deviation

Mean

(4)

Standard Deviation

( 2) Passing 9.50 mm sieve ( %) (2) Passing 4.75 mm sieve (%) ( 2) Passing 2.36 mm sieve (%)

77 .07 59. 71 44.14

5.53 6.31 5.50

77.14 58.64 43.43

5.38 8.63 7.06

0.0474 -0.433 -0.395

Tl07

Passing (3) 425 micron sieve (%) (3) Passing 75 micron sieve (%) Less than 13. 5 micron sieve (%)

63.79 49.36 37.21

6.24 8.20 9.47

67.29 52.14 39.64

7.00 9.17 9.74

2.3579* 1.6292 1.4559

Tl08

Liquid Limit

27.68

2.01

29.00

3.01

2.1261

Tl09

Plastic Limit

18.57

1.21

18.07

1.37

-2.3136*

Tll3

Linear Shrinkage (%)

3.79

0.87

3.96

0.91

0.7460

Maximum Dry Density (t/m 3 ) Optimum Moisture Content (%) Field Moisture Content (%)

1.94 12.30

0.05 1.20

Tl06

(1)

These test methods remain largely unchanged between 1958 and 1978

(2)

Expressed as percentage of material passing 9.50 mm sieve

(3)

Expressed as percentage of material passing 2.36 mm sieve

( 4)

Reported to two decimal places for statistical purposes only

Significant at p < .05 level

of the differences would be due to sample variability. It is apparent, however, that little breakdown of the shale had occurred in service. The latter study indicates that the repeated compaction test is a more appropriate method of pretreatment than the weathering test because breakdown occurred during construction rather than during service. CASE 3 - Sydney Breccia Quarries At present, three methods of pretreatment are specified for crushed rock (Department of Main Roads, 1979). The plasticity index after pretreatment must remain within the specification limits and must not increase by more than 3 over the plasticity index of the material before pretreatment. The three methods of pretreatment are: 1.

Pretreatment by repeated compaction (5 cycles)

Artificial weathering (10 cycles of wetting and drying)

Soaking in water at 65 0 C for 10 days.

In addition, a maximum Ten Percent Fines Value is specified. An investigation has been carried out to ascertain whether the three methods of pretreatment are, indeed, required in the specification. Considerable data have been collected since 1975 on the effects of pretreatment on breccia crushed rock materials which have been supplied to the Department's Parramatta Division. All available data were analysed for each of the three breccia quarries using the analysis of variance technique. In each case, the liquid limits after each method of pretreatment for one quarry were compared, as were the plastic limits. Analysis of variance data for the liquid limits are given in Table VI. Whilst the analysis of variance for Quarry A does not indicate a significant treatment effect, the liquid limits of the samples after soaking were significantly lower than the sample mean. For Quarry B there was a significant treatment effect with the liquid limits of the material after artificial weathering being significantly lower than the sample mean. For Quarry C there was no treatment effect. In each case, the mean of the liquid limits of the material pretreated by repeated compaction was higher than the mean of the material after either of the other methods of pretreatment (see Table VII). Analysis of variance data for plastic limits are given in Table VIII. The analysis indicates a significant treatment effect for Quarry A. The plastic limits of the material after repeated compaction were significantly lower than the sample mean. No treatment effect was indicated for Quarries Band c. Material from Quarry C, however, showed plastic limits after repeated compaction which were significantly lower than the sample mean. In each case, the mean of the plastic limits of the material pretreated by repeated compaction was lower than the mean of the material after either of the other two methods of pretreatment. Overall, analysis of variance does show some significant treatment effects which differ from quarry to quarry. As was noted above for each quarry, the method of pretreatment by repeated compaction yields the lowest mean plastic limit and the highest mean liquid limit, This means that overall pretreatment by repeated compaction would yield the highest plasticity index. Of course, an occasional sample may not necessarily follow this pattern.

TABLE VI ANALYSIS OF LIQUID LIMIT RESULTS AFTER PRETREATMENT Source of Variation

Quarry

Degre es of Freedom

2 88

Due to Groupings Due to Residuals

Total:

! Due t o Groupings 1

Due

Sum of Squares

40.41 761.89 Total:

2 94

t o Resi duals Total:

(X)

Mean Squares

F-value

20.20 8 .66

2 .3 34

20.63 4.24

4.863

1.85 2.05

.9 03

802.30 41. 26 398 .82

Total:

440.08

! I

' ., UU2 I

to Group ings

Due ::: o Rt2s iduals

3 .7 0 200.74

2 98

Total: 100

To tal:

204 .44

TABLE VII LIQUID LIMITS AFTER PRETREATMENT

Quarry

After Pretreatment by Repeated Compaction

After Pretreatment by Artificial Weathering

After Pretreatment by Soak i ng at 65°C

Mean

Standard Error

Mean

Standard Error

Mean

Standard Error

25.050

.655

24.538

.635

24.478

.413

Farley & 22.381 Lewers

.415

20.690

.385

21.915

.309

Readymix 19.167

.322

19.109

.285

18.738

.188

Pioneer

From a practical viewpoint there are disadvantages with both the artificial weathering and soaking procedures. Pretreatment by artifical weathering is slow and is subject to widespread variation in results because of the possibility of baking the sample. Pretreatment by soaking is also slow (10 days). Pretreatment by repeated compaction on the other hand is rapid (less than half a day) which means that results can be available within two to three days .

In view of the conclusions of Minty and Smith (1980) that the method of pretreatment by repeated compaction best simulates field conditions (see Case Study 2 above), and in view of the fact that pretreatment by repeated compaction yields the highest plasticity indices on breccia crushed rock base material, this method of pretreatment would appear to be the most appropriate. Whilst breakdown is probably a more significant problem with breccia than other crushed rock, it is considered that further studies on a wider range of materials are warranted to ascertain whether similar results occur. Such a situation is highly likely when one considers data such as those presented in the two earlier case studies described in this paper. A further area of investigation would be to study the effect of reducing the number of cycles of compactions from 5 to 3 or 2. At this stage, very little data are available to allow such comparisons to be made.

CONCLUSIONS

The three cases described above indicate that, provided an appropriate method of pretreatment is adopted, material performance can be estimated from routine test results. In most, but not all cases, the repeated compaction procedure appears mostly closely to simulate the performance of the material in service.

TABLE VIII ANALYSIS OF PLASTIC LIMIT RESULTS AFTER PRETREATMENT Quarry A

Source of Variation

Degrees of Freedom

Due to Groupings Due to Residuals

2 88

30.68 318.00

Total: 348.68

2 94

3.40 139.93

Total: 143.33

2 98

13.67 228.97

Total: 100

Total: 242.63

Total: B

Due to Groupings Due to Residuals Total:

Due to Groupings Due to Residuals

Sum of Squares

Mean Squares

F-value

15.34 3.61

4.245

1. 70 1.49

1.141

6.83 2.34

2.924

41 TABLE IX PLASTIC LIMITS AFTER PRETREATMENT

After Pretreatment by Soaking at 65°C

After Pretreatment by Repeated Compaction

After Pretreatment by Artificial Weathering

Mean

Standard Error

Mean

Standard Error

Mean

Standard Error

. 277

16.442

.343

16.633

.327

Farley & 15.500 Lewers

.195

15.534

.233

15.894

.192

Readymix 14.833

.374

15.783

.389

15.889

.178

Quarry

•

Pioneer

15.175

---

REFERENCES DEPARTMENT OF MAIN ROADS, NEW SOUTH WALES, 1960:

Manual No. 3 - Materials.

DEPARTMENT OF MAIN ROADS, NEW SOUTH WALES, 1975 (as amended): Testing Manual. Vol. 1: Soils, Aggregate, Concrete.

Materials

DEPARTMENT OF MAIN ROADS, NEW SOUTH WALES, 1979: Specification for the supply of natural gravel or crushed rock for road pavements (bitumen surfaced). (M.R. Form No. 744). DEPARTMENT OF MINES, NEW SOUTH WALES, 1965: Series Sheet.

Wilcannia 1:250 000 Geological

MINTY, E.J., and SMITH, R.B., 1980: Evaluation of "soft" rocks proposed for use in pavement construction in Australia (with special reference to New South Wales). Bulletin International Association of Engineering Geology, 22, 185-189. PACKHAM, G.H., (editor), 1969: The geology of New South Wales. of the Geological Society of Australia, 16.

Journal

SMITH, R.B., 1980: A laboratory and field study on mechanical breakdown of gravel during construction. Proceedings of the 10th Australian Road Research Board Conference, 10(3), 1-9.

42.

APPENDIX OUTLINE OF PRETREATMENT PROCEDURES Test Method TlOl - Pretreatm ent by Impact

The material is separated on 19 mm sieve. Material retained on the 19 mm sieve is immersed in water at room temperatu re for at least three hours and then drained for 15 minutes. Each particle larger than 19 mm is subjected to one blow of a 2.7 kg metal rammer dropping freely from the height of 75 to 100 m onto the particles located on a steel plate. All broken and unbroken pieces are collected and all portions of the sample are recombine d prior to preparati on and testing. Test Method Tl02 - Pretreatm ent by Compactio n

Approxim ately 6 kg of material is moist cured at a moisture content of 5% to 10%, in a covered container in an oven at a temperatu re not exceeding 50°c for at least 18 hours. The sample is separated on a 37.5 mm sieve. The material retained is broken to pass a 37.5 mm sieve. The portions are recombine d, the moisture restored if necessary to the range 5% to 10% and the material compacted . A 150 mm diameter mould of height approxim ately 200 mm is used. Material is compacted in three layers by 56 blows of a 2.7 kg rammer falling 300 mm. The material is then spread into a dish and allowed to dry sufficien tly so that preparati on can follow. Test Method Tl02a - Pretreatm ent by Repeated Compactio n

The sample is treated as in Test Method Tl02 except that after the first compactio n the material is removed from the mould, separated , remixed, water is added if necessary to maintain the moisture content in the range 5% to 10% and the material is then recompact ed . . This procedure is repeated until five compactio ns have been carried out in the case of crushed rock where the results of classific ation tests are compared before pretreatm ent and after the fifth compactio n. In the case of materials other than crushed rock the procedure is terminate d when at least 30% of the material passes a 2.36 mm sieve and at least ·two compactio ns have been carried out, or six compactio ns have been completed whichever occurs sooner. In addition the larger particles are subjected to 3 cycles of wetting and drying to ascertain whether the material will fret during quarrying operation . Test Method Tl03 - Pretreatm ent by Artificia l Weatherin g

The sample including both the coarse and fine fractions is placed in a dish, covered by water and allowed to stand for 18 to 20 hours. The clear water is then decanted, the remaining water evaporate d off and the sample dried on a hotplate. The process is continued until 10 cycles of wetting and drying have been completed . In some cases the material may be crushed prior to pretreatm ent. Test Method Tl04 - Pretreatm ent of Shales and Soft Rock

Large particles are crushed or broken to pass a 37.5 mm sieve. The sample is then subjected to 10 cycles of wetting and drying as in Test Method Tl03 and then compacted as in Test Method Tl02. The sample is then prepared and tested in the normal manner.

PROPERTIES OF QUEENSLAND AGGREGATES J.E. Martin*

ABSTRACT

This paper reviews the use, properties and suitability of particular rock types for coarse natural aggregates used in concrete and road sealing in Queensland. Coarse aggregates are obtained from alluvial gravel deposits and from quarries in a variety of igneous, metamorphic, and sedimentary rock types. The most important sources of aggregate are basalt and alluvial gravel. Rhyolite, trachyte, diorite, metagreywacke, hornfels and greenstone are significant sources. Minor sources include granite, adamellite, granodiorite, microgranite, granophyre, microdiorite, andesite, dolerite, quartz, welded tuff, indurated argillite, limestone, quartzite, and conglomerate. Serious deficiencies in the suitability or regional availability of aggregates have not been identified although deleterious alteration minerals and suspected alkali reactivity have led to the rejection of some aggregate sources for a particular use and have given some rock types a reputation of marginal quality. Improved quarrying practice could, in these instances,reduc e the amount of excessively weathered rock and could also correct the particle shape of some aggregates. More detailed evaluation of quarry rock resources is needed to assist in ensuring the optimum use of deposits now considered of marginal quality, and in conserving rock of high quality for special aggregate needs. INTRODUCTION Coarse aggregates for use in concrete and road sealing are obtained in Queensland from a variety of igneous and metamorphic rocks, some sedimentary rocks, and alluvial gravel. This variety provides a greater resource base than in other States, but implies greater impediments to a rapid evaluation of the State's resources. The selection of aggregate sources is further complicated by the lithological inhomogeneity of many geological units, the effects of past weathering regimes, and the deep weathering effect of the tropical and subtropical climate.

* Mr Martin is a Senior Geologist with the Geological Survey of Queensland.

The value of geolo gical expe rtise is being accep ted incre asing ly by the quarr ying indus try in recog nitio n of the funda ment al relat ionsh ip of geolo gy to the occu rrenc e and prop ertie s of quarr y rock, and becau se of the magn itude and capi tal-in tensi ve natur e of the indu stry. The inten ded use of an aggre gate dicta tes the signi fican ce of parti cula r aggre gate prop ertie s but, in gene ral, aggre gates for both conc rete and road seali ng are requi red to be durab le, dime nsion ally stabl e, and chem ically inert to resis t disin tegra tion by mech anica l stres s and decom posit ion by weath ering and chem ical agen ts. This revie w is based on avail able test data repor ted in publi shed and unpu blish ed repo rts of the Geol ogica l Surve y of Quee nslan d and of the Quee nslan d Main Roads Depa rtmen t. GRANITIC ROCKS The gran itic rocks inclu de gran ite, gran odio rite, adam ellite and tona lite, and are disti ngui shed only by their relat ive conte nt of plagi oclas e and ortho clase felds par, which does not sign ifica ntly affec t their prop ertie s as aggre gates . Aggr egate from gran odio rite is produ ced at Ceda rs Quar Quarr y near Mack ay, and from adam ellite at The Rocks ry and at Woodwards Quar ry, Home Hill. Gran ite is crush ed at Dunnes Quar ry, Ingha m, for road seali ng aggre gate. Disus ed quar ries in gran itic .rock s are at Ashg rove, Bowen, Town sville , Tully and Athe rton. Gran itic rocks are commonly consi dered to be infer ior sourc es of aggre gate becau se of their tende ncy towar ds poor abras ion resis tance and their repu tatio n for expen sive quarr ying. Large quart z crys tals in coars e gran itic rocks can cause exces sive wear in crush ing mach inery , and poor joint ing has a major influ ence on quarr ying costs . Howe ver,th e Enog gera Gran ite quarr ied at Ashg rove has provi ded an aggre gate of good stren gth, abras ion resis tance and parti cle shape , suita ble for use in high stren gth conc rete, but wide joint spaci ng is a probl em in part of The Rocks Quarr y and has contr ibute d to the aband onme nt of the Moun t Mackay Quar ry. Gran itic rocks are commonly repor ted to be more resis tant to weath ering and deute ric alter ation than the ferro magn esian rocks , but gran ites in the subtr opica l and tropi cal clima te of coas tal Quee nslan weat herin g. Coars e gran ites in parti cula r are susce d are prone to deep ptibl e to deep weat herin g, resul ting in a friab le rock with felds par and mica mine rals in an advan ced state of decom posit ion. Felds pars alter to kaol inite , hallo ysite , and vario us assoc iated mine rals, and bioti te may alter to green ish chlo ritesmec tite mine rals (Bell , 1977 ). Biot ite hornb lende tona lite at Taron g exhi bits minor alter ation of plagi oclas e to seric ite and of hornb lende to chlo rite (Warner and Bark er, 1979 ). A smal l amou nt of aggre gate for conc rete and road seali ng is produ ced from shear ed micr ogran ite at King 's Beach Quar ry, Bowe n. warne r and Barke r (1979 ) repo rt that micr ogran ite of the Tarom eo Tona lite at Maid enwe ll could provi de a stron g, sound aggre gate. The char acter istic irreg ular inter grow th of quart z and felds par in grano phyre , crush ed for railw ay balla st at the Bee Creek Quar ry near Nebo, contr ibute s to good stren gth. Testi ng of gran ite at Wall angar ra and Maid enwe ll, adam ellite east of Mount Cooro y, gran odio rite at Naran gbah, and tona lite at Maid enwe ll indic ates that all of the rocks could provi de suffi cien tly stron g and durab le aggre gates .

COMENDITE, MANGERITE

at the Comend ite (alkali rhyolit e) has been crushed for concre te aggreg ate from d Mount Coolum Quarry , and road sealing aggreg ate has been produce Quarry . other Tertiar y intrusi ve plugs at the Ngungun Quarry and Beerbur rum The riebec kite comend ite at Ngungun is bleache d to an apprec iable depth, al sugges ting kaolin isation of feldspa r. Wylde (1976a) and Poole (person and ng splitti commu nication ) report that the aggreg ate is flaky and prone to to two crushin g in road sealing , resulti ng in partia l deterio ration within ten years. Petrolo gical examin ation of various comend ites of the Glass House Mounta ins by Shipway (1961) indica tes that the rock texture could ated contrib ute to flakine ss in the aggreg ate, and this was probab ly accentu that confirm by the crushin g techniq ue at the Ngungun Quarry . Test results g the aggreg ate is flaky. It also exceed s the Main Roads Departm ent crushin is and day, value limit of 20 for greate r than 150 comme rcial vehicle s per approac hing the Austra lian Standa rd limits for strengt h and abrasio n resista nce for concre te aggreg ate. The rock quarrie d at Mount Coolum is a hard, massiv e, relativ ely fresh comend ite speckle d with black ferroma gnesian minera ls. Willmo tt (1978) tests reports that some screeni ngs are brittle . Mielen z alkali reactiv ity ious deleter be could on comend ite from Beerbur rum sugges t that the rock in concre te althoug h tests on sample s from seven other comend ite plugs gave innocuo us results . by Five comend ite plugs in the Sunshin e Coast area have been investi gated ly possib ained, O'Flynn (1979) and Trezise (1978). Well-j ointed , fine-gr ite of bleache d rock at the Mount Cooroo ra Quarry is flaky and weak. Comend at ite comend red weathe y variab le quality at Lawnv ille, and fresh to slightl ation degrad gton Washin Upper Six Mile Creek have adequa te streng th, but low ite at values indicat e poor durabi lity. Slight ly foliate d riebec kite comend both in Mounta Round at Saddleb ack, and altered glassy riebec kite comend ite perform poorly in soundn ess tests. or On the basis of this testing it is conside red that bleache d, altered to y unlikel are on, foliati weathe red comend ite, and comend ite exhibi ting te. be suitab le for use in road sealing or concre for Mange rite, the medium -graine d alkali rhyoli te quarrie d at Mount Cooroy and te concre for ess soundn and use in sea walls, has suitab le streng th road sealing aggreg ate when fresh to slightl y weathe red (Trezis e, 1978). RHYOLITE and Rhyoli te is crushed for concre te aggreg ate at the Image Flat Quarry Quarry s Olsen' at sealing road for r, at the Bli Bli Road Quarry at Nambou near Proser pine, and for concre te, road sealing and ballas t at the Bohle and Quarry , Townsv ille. There are disused quarrie s in rhyolit e at Nebo Rockham pton. The aggreg ate produce d from rhyoli te of the North Arm Volcan ics at the Image Flat Quarry varies in quality because of flow banding , minor interbedded tuff, and bleachi ng resulti ng from weathe ring. Wylde (1976a) road reports that the screeni ngs are flaky and are probab ly too soft for al (person Poole . service in g crushin and sealing , resulti ng in splitti ng sealing road as lity durabi poor has te rhyoli commu nication ) confirm s that the

aggreg ate. These tenden cies towards low strengt h and flakine ss are not eviden t in the few test results availab le, but some of the users of this aggreg ate in concre te report poor aggrega t e shape and dustin ess. The thicker flows of more uniform petrolo gy are the most prospe ctive. Wylde (1976a) also reports deterio ration of rhyolit e crushed at the Red Hill Quarry , but the rock there is weathe red and altered . The test results on rhyolit e sampled by Gorhan (1971), Denaro (1977) and O'Flynn (1979) indicat e a strong tendenc y towards a l kali aggreg ate reactiv ity. Testing of rhyolit e of the Lower Bowen Volcan ics and of the Mount Byron Volcan ics shows that, within the same format ion, the rock of one flow may be innocuo us wherea s anothe r rhyolit e band may be potent ially deleter ious. Rhyoli tes and other acid to interm ediate volcan ic rocks consti tute signifi cant potent ial sources of aggreg ate in Queens land, and require more detaile d investi gation s of their suscep tibility to alkali reactiv ity. TRACHYRHYOLITE Trachy rhyolit e worked near Tewant in in Saunde rs' Quar r y and in Lenehan and Earle's Quarry for fill and road-pa vement gravel s has been tested for aggreg ate suitab ility by Trezise (1978). The rock at Saunde rs' Quarry could be suitab le for concre te aggreg ate, but the trachy rhyolit e at Lenehan and Earle's Quarry is unsoun d. The poor durabi lity of this rock is probab ly caused by volcan ic glass, which occurs in highly fractur ed narrow dykes. DIORITE, MICRODIORITE Diorite is quarrie d for concre te and road sealing aggreg ate at Cedars Quarry and at Woodw ard's Quarry , near Mackay . Disused quarrie s are at Gladsto ne, near Mackay at Mount Basset t, and at Home Hill. Microd iorite is associa ted with the diorite at Cedars Quarry and Woodw ard's Quarry , and is the sole rock type at the Farleig h Quarry . It was previou sly also quarrie d at Mount Basset t. The diorite and microd iorite at Cedars Quarry both provide a high quality , durabl e, abrasi on-res istant aggreg ate. Fresh diorite quarrie d from an intrusi ve dyke at the disused Burua Quarry near Gladsto ne has high strengt h and would provide a durable aggreg ate (Warne r, 1976). Washin gton degrad ation and sodium sulpha te soundn ess tests indicat e that the stockp iled materi al contain ing 10 per cent of weathe red rock, is less durable than the fresh rock but still satisfi es the require ments for aggreg ate for concre te and road sealing . The particl e shape of the stockp iled aggreg ate is accepta ble also. The diorite previou sly quarrie d at Marooc hydore for use in sea walls varies from diorite to andesi te and is in parts br ecciate d (Laycoc k, 1963). This petrolo gical variati on is reflect ed in a variati on in specifi c gravity and could have led to problem s of quality contr ol in the produc tion of aggreg ate. A crushin g test by a comme rcial crushe r also resulte d in flaky screen ings. Three diorite deposi ts in the Sunshin e Coast area, tested by Willmo tt (1978), are potent ial sources of strong and durable aggreg ate. The diorite near Eumundi contain s chlori te but this is unlikel y to be deleter ious in aggreg ate. Large plagioc lase laths could, howeve r, affect the particl e shape in small screeni ng sizes.

ANDESITE Andesite is crushed for use in concret e, road sealing, and railway ballast at Dionysiu s Quarry, Goomeri . It is quarried for road sealing and concrete aggrega te at the Kianga Quarry, Moura: at Cedars Quarry, Glenalla : and at the Proserpi ne Shire Council Foxdale Quarry near Proserp ine. Road sealing aggrega te is also produced at the Widgee Shire Council Quarry at Gympie, and at Olsens Quarry, Proserp ine. There are disused railway ballast quarries at Koumala and Nebo. The fine grain size and felted texture of andesite are consider ed to contribu te to its durabil ity as road sealing aggrega te. Few test results are availab le on the andesite quarried in Queensla nd. Some non-stan dard testing of andesite of the Neara Volcani cs at Dionysiu s Quarry, carried out by the Main Roads Departm ent and the Queensla nd Water Resource s Commiss ion, indicate s that the aggrega te may be unsound if used in concrete in extreme exposure conditio ns. The andesite at Cedars Quarry is an abrasion resistan t, durable rock. Willmot t (1978) and Trezise (1978) report that andesite of the North Arm Volcanic s at Palmwoo ds, east of Cooroy, and at Tewantin could provide strong, durable aggrega te on the basis of the aggrega te crushing , sulphate soundne ss, and Washing ton degrada tion test results. However , the andesite at Palmwoods is closely penetrat ed in places by veinlets of chlorite , which would result in poor aggrega te strength and chlorite coatings on screenin gs. Testing of the andesite at Tewantin by the Mielenz method indicate d that some samples could be alkali reactive , but confirm ation of this result by further investig ations is required , as the other Queensla nd andesite s tested for alkali reactiv ity are innocuo us. There is, however , evidence of damaging alkali reactiv ity in the andesite s of other countri es, includin g those of New Zealand. Hard, fresh .rock of the Bellthor pe Andesite is suitable for aggrega te for concrete and road sealing on the basis of Washing ton degrada tion and sodium sulphate testing (O'Flynn , 1979). Andesite of the Lower Bowen Volcani cs near Sarina (Gorhan, 1971), and of an intrusiv e dyke near Gladston e (Warner, 1977), performe d adequat ely in soundne ss testing although the rock was moderat ely weather ed. Andesite of the Gilla Andesite at Yarraman contains five to ten per cent of seconda ry minerals (Warner and Barker, 1979). Mafic phenocr ysts have been altered to chlorite , and plagioc lase has been altered to sericite but this seconda ry mineral content would not affect the suitabi lity of the andesite for road sealing and concrete aggrega te. TRACHYTE Tertiary intrusiv e plugs of trachyte are quarried for road sealing and ballast at the Moodlu Quarry, Caboolt ure: for use in concrete and road sealing at the Mount Juillera t Quarry, Redbank Plains: and for concrete aggrega te at Johnsto ne's Quarry, Redbank Plains. The Mount Jim Crow Quarry at Yeppoon is disused . The variatio n in the results of tests carried out on the aeg1r1ne trachyte at Moodlu is attribut ed to the sampling of differen t parts of the quarry (Daines, persona l commun ication). There appears to be little petrolo gical variatio n in the quarry, however , except for weathere d rock at the surface and at the perimete r of the intrusio n. Clay mineral s are not obvious except near the quarry floor, where a dark mineral occurs in some joints (Wylde, 1976a).

The aggrega te crushing values for five sizes of screenin gs range from 25 to 13 and illustra te the tendency of smaller aggrega te sizes to have higher strength than the larger sizes. The flakines s index test results illustra te the tendency to poorer particle shape in the smaller screenin g sizes. The fresh to slightly weathere d trachyte quarried at Mount Juillera t meets the requirem ents of strength , abrasion resistan ce and durabil ity for use in concrete and road sealing. The consiste ncy of the wet and dry crushing value test results on face samples confirms the good strength charact eristics of the rock present ly being quarried for aggrega te. The flakines s index of the screenin gs is consiste ntly low. A dark green mineral (?chlori te) occurs in joints in the lower part of the quarry, and a bright green mi neral is more widespre ad. Although neither mineral appears to be deleteri ous, both have been collecte d for identifi cation at the CSIRO Division of Building Research . Moderat ely weathere d rock has adequate strength , but · performs poorly in the Texas ball mill, sulphate soundne ss and Washing ton degrada tion tests. The aggrega te charact eristics of trachyte to be quarried from olivine trachyte north of Beerburr um (Martin, 1979 ) are expected to be similar . to those of the Moodlu trachyte . Apparen tly fresh aegirine trachyte with slight foliatio n, sampled from Mount Miketee bumulgr ai by O'Flynn (1979), disinteg rated in soundne ss testing. OOLERITE Tertiary intrusio ns of dolerite are quarried for use in both concrete and road sealing at Eastmen t's Ridge Quarry, Warwick ; for road screenin gs at Wittenh agen's Pit, Aratula ; and for concrete aggrega te at the Rylance Quarry, Coleyvi lle. Disused quarries are at Coleyvi lle and at Memerambi. The degrada tion of aggrega te consisti ng of basic igneous rocks containi ng alterati on mineral s is well documen ted in road failures in the United States of America , in Canada, in the United Kingdom, in South Africa, and in Austral ia. Some Australi an dolerite s, which appear to be fresh and unaltere d, have performe d poorly in durabil ity tests because of fine grained , incipien t alterati on. The common alterati on mineral s in Queensla nd dolerite s are chlorite , zeolites , iddings ite, and clay mineral s. Iddings itised olivine , if present in excess of 15 to 25 per cent, is likely to cause in-servi ce deterior ation of road sealing aggrega te. Warner (1972) reports that the dolerite of the Main Range Volcani cs at the Kingaroy Shire Council Quarry, and at two other intrusio ns east of Memerambi, contains minor zeol ite and as much as 40 per cent iddings ite. The quarry is now disused because of the proven poor durabil ity of the rock as road sealing aggrega te. Dolerite general ly is consider ed to provide a poorer aggrega te than basalt because of its coarser grain size and the poor intergro wth of its constitu ent mineral s. This is illustra ted in the results of tests conducte d in 1974 by the Main Roads Departm ent on the differen t rocks of the upper sill quarried by Rylance Collier ies and Brickwo rks Pty Ltd at Coleyvi lle. The tests were carried out on the same sample grading (-19.0 +13.2 mm) of coarse dolerite and finer grained dolerite (or basalt). The results demonst rate that the finer grained rock is stronge r, is more resistan t to abrasion , and is likely to provide a more durable aggrega te than the coarser dolerite . Coarse dolerite of the bottom sill at this quarry contains abundan t zeolites and is unsuitab le for use in concrete and road sealing . Fresh rock from the Coleyvi lle Quarry, previou sly operated by the Main Roads Departm ent, has proven to be a road sealing aggrega te of good quality.

Fresh dolerite quarried at Eastment's Ridge is suitable for road sealing and for concrete aggregate, but road sealing aggregate produced from weathered rock in this quarry suffered splitting, crushing, and complete deterioration within two years of use (Wylde, 1975). The range of Washington degradation values obtained from tests conducted by the Main Roads Department on core samples confirms the poor durability of the weathered rock. BASALT Basalt is second only to river gravel in terms of the number of workings and the amount of aggregate produced. Of 31 quarries currently working basalt in Queensland, eleven produce aggregate for both concrete and road sealing, four produce concrete aggregate, ten produce road sealing aggregate, and six quarries also produce railway ballast. The Moggill Quarry is in the Sugars Basalt, of Triassic age. All the other basalts quarried are of Tertiary age. The basalt quarries are mainly in the southeast Moreton Region, in the Toowoomba district, in the Wide Bay-Burnett Region, in the Bowen Basin, and on the Atherton Tableland. The popularity of basalt as aggregate is to some extent traditional. Basalt is preferred in the quarrying industry because of the lower maintenance costs on crushing machinery and the generally lower costs of explosives, especially where the rock is closely jointed. Basalt is also preferred because of its surface texture, polishing resistance, and blocky particle shape. Its felted texture contributes to its strength as aggregate. Basalt aggregates may contain excessive amounts of deleterious minerals, however, and are particularly susceptible to deterioration in use and even during stockpiling. An additional problem in establishing basalt quarries in Queensland is that the flows are commonly thin. The top of each flow would be vesicular or weathered and this material is seldom suitable as aggregate. The effect of secondary minerals on the suitability of basalt for road sealing aggregate, road pavement gravels and concrete aggregate has been investigated extensively in Australia. This work on the formation, distribution, and deleterious effect of secondary minerals formed under different alteration conditions has been carried out by the Australian Road Research Board (Wylde, 1975; 1976b, c, d; 1979), by the CSIRO Division of Building Research (Cole, 1976, 1977, 1979; Cole and Lancucki, 1976; Cole and Beresford, 1976), by the Country Roads Board of Victoria (Nyoeger, 1978) and by Bell (1977). Local investigations also are being carried out by the Materials Branch of the Queensland Main Roads Department (Basford, 1975). Secondary minerals in basalts may be derived from both the feldspars and ferromagnesian minerals. Fe_ldspars may alter to unstable and hydrophilic kaolin-type clays such as montmorillonite and halloysite, and to zeolites. The ferromagnesian minerals can alter to limonite, chlorite smectites, and serpentine. Chlorite smectites and serpentine are highly unstable and degrade into clays. Limonite is relatively stable but is nevertheless weak. Basaltic glass can alter to secondary minerals such as montmorillonite. Calcite is water-soluble and breaks down readily. Iddingsite, the common deuteric alteration product of olivine, does not absorb water to the extent that the chlorite smectites do. Wylde (1975) reports that the deep weathering profiles common in Queensland basalts have formed under oxidising-leaching conditions, which favour the formation of kaolin clays and hydrated iron oxides. Green chlorite-smectite clay minerals are present in the lower levels of the Moggill Quarry and the Coleyville Quarry. They may be present also in other basalt quarries in Queensland.

Vo lca nic gla ss is common in de let eri ou s in fre sh, un alt Qu een sla nd ba sal ts bu t it doe s no t app ear to be ere d agg reg ate . The ba sal t of the Main Range Vo lca nic s qu arr ied at Tar ong has a ver y fin e gro und ma ss con tai nin g 60 per cen t gla ss (W arn er and Ba rke r, 197 9). The ba sal t wo rke d at the Arnby Qu arr y has 35 to 40 per cen t int ers ert al gla ss (Sh ipw ay, 196 2) and has bee n use d for roa d sea lin g agg reg ate for many ye ars . Vo lca nic ba sal t at the Mo ggi ll Qu arr gla ss in the alt ere d y, how eve r, is de vit rif ied mo ntm ori llo nit e cla ys (Ba to ch lor ite and sfo rd, 197 5). The roc k in the low er lev els of the qu arr y is su ita ble for agg reg ate s, con tai nin g 7 to 11 mi ner als and as much as 6 per cen t of sec ond ary per cen t gla ss. Tow ard s the top of the qu arr y, in the alt ere d zon e, the ba sal t con tai ns 20 to 50 per cen t of ·sec ond ary mi ner als of wh ich 25 per cen t is de vit rif ied gla ss. The Wa shi ngt on deg rad ati on tes t res ult s con firm tha t the alt ere d roc k wo uld as agg reg ate . hav e poo r du rab ili ty Ze oli te mi ner als occ ur in ve sic les in the ba sal t at the Mo ggi ll Qu arr y (Ba sfo rd, 197 5) and at the Tar ong Qu arr y (W arn er and bee n not ed at the Rocky Cre Ba ek Qu arr y (W illm ott , 198 0a) rke r, 197 9), and hav e Qu arr y (W illm ott , 198 0b) . and at the Pal me rst on Ze oli tes als o occ ur in ba sal t at We nge nvi lle (Warner and Ba rke r, 197 9). tha n 5 per cen t to a maximu The ze oli te co nte nt ran ges ov era ll fro m les s m of 10 per cen t, and is un lik ely to be de let eri ou s in agg reg ate s use d for con cre te and roa d sea lin g. The tes t res ult s av ail ab le ind ica te tha t fre sh to sli wi th a low con ten t of sec ond ary mi ner als sho uld pro gh tly we ath ere d ba sal t vid e a du rab le agg reg ate . Tho rou gh eva lua tio n of the pro pe rti es of the qu arr y roc k and car efu l qu arr yin g pra cti ce can imp rov e the qu ali ty of ba sal t agg reg ate s for con cre te and roa d sea lin g sig nif ica ntl y. The we ath eri ng is va ria ble in pa rti cu lar ly in lar ge qu arr man ies suc h as the Mount Marrow y ba sal t qu arr ies , Qu arr y, wh ich work sev era Qu arr y and the Tar ong l flo ws . The we ath ere d roc k sho uld be avo ide d by sel ec tiv e qu arr yin g if an acc ept abl e pro du ct can no t be ob tai ned by sca lpi ng . Some va ria tio n in pa rti cle sha pe occ urs in the agg reg suc h as the Bri dge Str ee t ate fro m some qu arr ies Qu arr y. Po orl y fra ctu red and fin er gra ine d ba sal t ten ds to pro vid e a fla kie r agg reg ate , and may req uir e imp act cru shi ng to ob tai n an agg reg ate of acc ept abl e pa rti cle sha pe. QUARTZ Wh ite qu art z is qu arr ied fro m a lar ge vei n in sil tst on e and qu art zit e at the sm all Boondooma Qu arr y. Ma jor joi nts in the qu art z are fil led wit h red cla y wh ich can be rem oved by sca lpi ng . Inc ipi en t iro nst ain ed fra ctu res occ ur thr oug hou t the vei n bu t agg reg ate . The fla ky scr een the se ble ach du rin g exp osu re of the ing s pro duc ed at the qu arr con cre te agg reg ate in lan y are use d for exp ose d dsc api ng and in orn am ent al work in co ast al sou the ast Qu een sla nd, wh ere sui tab ly cle an qu art z and sca rce . qu art zit e app ear to be WELDED TUFF Welded tuf f is cru she d for Coolum; for roa d sea lin g con cre te agg reg ate at the To olb oro ugh Road Qu arr agg reg ate at Dunnes Qu arr y, Ing ham ; and for bot h y, use s at the Ya rra ma n Qu arr y,a nd at the Gre en Hi ll Qu arr y on Th urs day Isl an d. Co ncr ete agg reg ate , roa d sea lin g agg reg ate and rai lw ay ba lla st are pro duc ed at the Ro sen eat h Qu arr y, To wn svi lle , and at the Mo unt Co rde lia Qu arr y, Ing ham Dis use d qu arr ies in we lde d . tuf f are at Sta ffo rd, Ne bo, and Th urs day Isl an d.

•

51 Welded tuffs general ly should provide tough, abrasion resistan t, durable aggrega tes. Their composi tion of phenocr ysts and rock fragmen ts in a glassy groundm ass results in an aggrega te of suitable surface texture for high strength concrete and for skid-re sistant road surfacin g. The welded tuffs quarried in southea st Queensla nd are abrasive on crushing machine ry. Close jointing is required for effectiv e rock break-o ut by blasting . There appears to be little use of welded tuffs as aggrega tes in the other Austral ian states, but it is possible that welded tuffs associat ed with volcanic flows have not been recognis ed as such. Rhyolit ic welded tuft has been worked in several quarries in the inner suburbs of Brisban e. The last of these quarries in the Brisbane Tuff, the Webster Road Quarry, produced exposed aggrega te for concrete (Willmo tt, 1979). The lithic crystal welded tuff of the North Arm Volcani cs, quarried for concrete aggrega te at Coolum and for road pavemen t gravel at Glass House Mountai ns, consists of rock fragmen ts and feldspar in a fine-gra ined glassy groundm ass. Slight kaolinis ation of feldspar may be a surface weatheri ng effect and is not deleteri ous. However , petrolo gical variatio ns in the sheets of tuff may influenc e aggrega te propert ies. Rhyolit ic welded tuff of the North Arm Volcani cs, investig ated at the Coolool abin damsite by Barker (1976a), appears to be suitably strong and durable for concrete aggrega te, even when moderat ely weathere d. The Yarraman Quarry has been establis hed recently in andesiti c crystal lithic tuff of the Gilla Andesit e. The rock consists of andesite fragmen ts and plagioc lase crystals in a fine-gra ined devitrif ied glassy groundm ass of feldspar and (?)chlo rite. The minor seconda ry minerals (sericit e and green mica) are unlikely to be deleteri ous in concrete aggrega te (Warner and Barker, 1979). Rhyolit ic welded tuff of the Glen Gordon Volcani cs is fracture d and moderat ely weathere d at the Mount Cordelia Quarry. Rock of the same formatio n is difficu lt to blast and crush at Dunnes Quarry, where it is fresh to slightly weathere d and sparsely fracture d (Willmo tt, 1980b). The Green Hill Quarry on Thursday Island is in dacitic welded tuff of the Goods Island Ignimbr ite. The aggrega te tested by Warner (1975) is strong and sufficie ntly durable , and has a low content of seconda ry mineral s. The rhyoliti c welded tuff of the Endeavo ur Strait Ignimbr ite, previou sly worked at the Milman Hill Quarry, has a lower seconda ry mineral content ; this may have influenc ed its better performa nce in the durabil ity tests. Dacite crystal tuff of the Carmila Beds near Mackay, investig ated by Findlay (1975) as a possible source of concrete aggrega te, gave satisfac tory results in testing for soundne ss and alkali reactiv ity. Acid and interme diate welded tuffs of the Campwyn Beds near Hay Point, investig ated for concrete aggrega te by Barker (197Gb), are suitable on the basis of tests for strength , abrasion resistan ce and soundne ss. The Mielenz test, however , indicate s that much of the rock, especia lly the welded dacitic crystal tuff, is alkali reactive . Some deleteri ous Mielenz test results also have been obtained for rhyoliti c welded tuff of the Lower Bowen Volcanic s (Gorhan, 1971). Further petrolo gical investig ation and mortar bar testing of these possible sources of aggrega te is required .

ARGILLITE Indura ted argill ite of the Berser ker Beds from the Nerim bera Quarry , Rockha mpton, is used succe ssfull y as concre te and road sealin g aggreg ate. Traces of sulphi des are presen t,but these do not appear to be delete rious in the aggreg ate. Howev er, invest igatio ns of the suitab ility of argill ite of the Neran leigh- Fernva le Beds and of the Curtis Island Group sugge st that this rock type is gener ally weak and of poor durab ility unless it is unwea thered and excep tional ly indura ted. Fresh argill ite of the Neran leigh- Fernv ale Beds at the Wolffd ene damsi te is barely satisf actory in soundn ess testin g, and moder ately weathe red rock fails badly by splitt ing and flakin g (Wells and Findla y, 1971). Some fresh and slight ly weathe red argill ite proved to be delete rious in the Mielen z alkali reacti vity test. Moder ately weathe red argill ite of the Curtis Island Group is satisf actory in the sulpha te soundn ess test (Barke r, 1979), but moder ately to highly weathe red rock fails the test badly (Warne r, 1977). GREENSTONE Green stone of the Rocksb erg Green stone is worked for concre te and road sealin g aggreg ates at the Petrie Quarry . Green stone of the Neran leighFernv ale Beds has been used in the constr uction of the Splity ard Creek Dam and has been crushe d for road sealin g aggreg ate at Cochr ane's Quarry , Northb rook. There are disuse d aggreg ate quarri es in greens tone at Petrie and at Borum ba. The greens tone of the Rocksb erg Green stone i s a low-gr ade region ally metam orphos ed basic volcan ic rock, varyin g from hard and massiv e to foliat ed and schist ose. It consis ts of pheno crysts of augite in a matrix of feldsp ar, epido te, actino lite, chlor ite, and iron oxide (Warne r, 1962). The fresh, massiv e greens tone is becomi ng a signif icant source of aggreg ate as a result of increa sed produ ction of concre te aggreg ate at the Petrie Quarry . Wide joint spacin g in places result s in poor breako ut in blasti ng (Willm ott, 1979). Where foliat ed, the rock is unsuit able for aggreg ate becaus e of poor partic le shape and a tenden cy to poor durab ility. Excess ive veinle ts of epidot e are delete rious. The rock at the Petrie Quarry has been invest igated by Davies and McInty re (1979) . Elong ate interlo cking actino lite crysta ls in the rock matrix impart a high intact rock tensil e streng th. The fresh rock also has high compr essive streng th and durab ility. The matrix crysta ls, espec ially actino lite, exhib it slight prefe rentia l orient ation which is expres sed as a tenden cy to foliat ion. The aggreg ate partic le shape approa ches or exceed s the accept ance limit, and demon strates the need for care in crushi ng. The relati vely high polish ed stone value is attrib uted to the fine-g rained porph yrobla stic textur e and to the differ ence in hardne ss betwee n the porph yrobla sts and the matrix miner als. Reduce d streng th and durab ility of the slight ly weathe red rock are attrib uted to mixed layer chlori te-cla y miner als, which form at crysta l bound aries and at cleava ges in the slight ly weathe red rock. In moder ately weathe red rock, epidot e and pyroxe ne pheno crysts are replac ed by chlori te-cla y miner als, actino lite is partly replac ed, and chlor ite and epidot e coat joint surfac es. The disuse d Paramo unt Quarry northw est of the Petrie Quarry appear s to be situat ed in the same band of massiv e greens tone. The variat ion in the specif ic gravit y (2.82 to 2.97) of the greens tone sample d by Manion (1966) is partly attrib uted to the presen ce of calcit e. Fresh greens tone,s ample d by O'Flyn n (1979) near Rocks berg,i s durabl e but is foliat ed in places . The greens tone of the Neran leigh- Fernva le Beds at Cochr ane's Quarry is strong , and is not foliat ed.

QUARTZITE Quartzite of the Neranleig h-Fernval e Beds is quarried for concrete aggregate between Brisbane and the Gold Coast at the Readymix Pine Mountain Quarry, at Karreman Bros. Quarry, at the Daisy Hill Quarry, and at the M & M Quarry. There are disused quarries in this formation at Mudgeerab a and in the Barron River Metamorp hics near Cairns. The quartzite s investiga ted in Queenslan d appear to have common problems in aggregate shape, contamina tion by fines, high productio n costs, and variable alkali reactivit y. Several quarries southeast of Br'isbane are producing road-pave ment gravels from quartzite bands in the Neranleig h-Fernval e Beds. Until recently, this rock has been considere d unsuitabl e for aggregate of better quality because of a high fines content resulting from finely interbedd ed shale and argillite , and potential alkali reactivit y problems with cement (Willmott , 1979). The significa nce of some deleterio us results in the Mielenz test requires further investiga tion. The quartzite is somewhat brittle and can yield flaky and elongated aggregate , even when homogeneous and without tendency to foliation . Particula r attention to crushing technique and particle shape therefore is required. Further increased productio n of concrete aggregate from quartzite of the Neranleig h-Fernval e Beds is expected, neverthel ess, because of the proximity of these deposits to Brisbane and the Gold Coast. Quartzite of the Barron River Metamorp hics has been crushed for aggregate for concrete and road sealing at the Smithfiel d Quarry, but the quality of the rock is variable. The massive quartzite band previousl y quarried for concrete aggregate at the White Rock Quarry is expensive to crush (Willmott and Muller, 1980). Warner and Findlay (1973) have investiga ted the aggregate propertie s of the Barron River Metamorp hics at Freshwate r Creek near Cairns. The foliated rock may crush to aggregate of poor particle shape unless particula r care is taken with selection of the most massive rock, and with crushing technique s. Some slightly weathered quartzite showed potential alkali reactivit y in initial Mielenz tests, but repeat tests showed innocuous reaction. An early assessmen t of the mortar bar tests suggested that none of the samples was likely to exceed the expansion limits. Barker and Hofmann (1973) found that some of the quartzite of the Judenan Beds west of Gunpowder is potential ly deleterio us in the Mielenz test. Fine joint infilling s also may reduce the suitabili ty of the quartzite for concrete aggregate . HORNFELS

This rock is a major source of aggregate in Queenslan d. Hornfels is crushed mainly for asphaltic aggregate at the Mount Coot-tha Quarry; for concrete aggregate , bitumen screening s and asphaltic aggregate at the Narangba Quarry; and for concrete and road sealing aggregate s at the Hodgleigh Quarry near Nanango. The concrete aggregate for the construct ion of the Somerset Dam was quarried from hornfelse d Neara Volcanics . As hornfels is a contact-m etamorphi c rock, its propertie s as aggregate vary widely according to the original rock, the proximity of the igneous intrusion , and the degree of recrystal lisation. A particula rly detailed evaluatio n of hornfels deposits is therefore essential before quarrying . Hornfels is generally hard, durable and tough when fresh. Fine-grai ned hornfels can,

however be brittle, and foliatio n can lead to loss of soundne ss. When weathere d and fracture d, poor durabil ity can result from clay and other alterati on mineral s. The hornfels derived from basic volcanic rocks is the most suscept ible to deterior ation resultin g from weather ing and alterati on mineral s. Siliceou s hornfels is the most resistan t to degrada tion. The hornfels ed Bunya Phyllite at the Mount Coot-th a Quarry has provided strong and abrasio n-resist ant bitumen screenin gs and some concrete aggrega te in the past. The main use of the aggrega te now is for asphalt ic concret e. The Narangba h Quarry is in hornfels ed basic volcanic rocks (greenst one) of the Kurwongbah Beds. The rock is of variable quality and the aggrega te needs washing to remove clay derived from altered and highly weathere d rock. Wylde (1976a) reports that zeolites , (?)talc and carbona tes occur on joint planes in variable amounts , and some sulphide is present . When fresh and unaltere d, the rock is strong, abrasio n-resist ant, and resistan t to polishin g. Moderat ely weathere d rock, unaltere d slighly weathere d rock and altered slightly weathere d rock have performe d poorly in Washing ton degrada tion and sulphate soundne ss tests conducte d by the Main Roads Departm ent in 1979. Selectiv e quarryin g of fresh rock, scalping , and washing appear necessar y to provide an acceptab le aggrega te. Two hornfels deposits of the Kurwongbah Beds, tested by Willmot t in 1974 and by O'Flynn (1979), should provide durable aggrega te. Foliatio n in the banded biotite hornfels at Bracalb a, southwe st of Caboolt ure, may lead to excessiv e fines on crushing , and there is some chloriti sation of biotite and sericiti sation of potash feldspa r. The hornfels at D'Aguil ar also exhibits quartz-m ica foliatio n. The fresh to slightly weathere d rock appears suitable for concrete aggrega te, but the more weathere d hornfels is very fracture d, with chlorite , epidote and zeolite on joint planes. The fine-gra ined hornfels of the Marongh i Creek Beds crushed at the Hodgleig h Quarry is a recryst allised silicifi ed mudstone which appears to be free from deleteri ous seconda ry mineral s (Warner and Barker, 1979). The aggrega te is tough, durable , and well-sha ped. GREYWACKE Metagrey wacke of the Neranle igh-Fern vale Beds is the major source of quarry rock for concrete and road sealing aggrega tes for the Gold Coast. It is crushed at the Pioneer Gilston Quarry, at the Readymix West Burleigh Quarry, and at the ·Hymix Nerang Quarry. Disused quarries are at West Burleigh , Advance town, and Coombabah. Disused quarries in other parts of Queensla nd are the Stratfor d Quarry in Barron River Metamor phics, the Yarwun Quarry in Berserke r Beds, and the Catfish Creek Quarry in Mount Holly Beds. Fresh to slightly weathere d metagrey wacke of the Neranle igh-Fern vale Beds provides a strong, abrasio n-resist ant and durable aggrega te, and will continue to be a prime source of aggrega te for the Gold Coast. The rock crushes to an angular aggrega te with a rough, granula r surface texture, and low to moderate water absorpti on. Thin intercal ations of argillit e in the greywack e are common; even when fresh, these are likely to be deleteri ous in aggrega te and should be avoided .

•

The petrological significance of some marginally deleterious Mielenz test results for alkali reactivity has not been determined. These results have been obtained from greywacke sampled from the Pioneer Gilston Quarry and from the Merrimac Quarry in 1974, and from the Wolffdene damsite (Wells and Findlay, 1971). The greywacke at Gilston, nevertheless, has been used extensively for concrete aggregate for many years without apparent adverse effects. Fresh to slightly weathered greywacke at the Advancetown damsite proved to be sufficiently strong and durable for aggregate use. At the Wolffdene damsite spillway location, slightly weathered greywacke is sound, moderately weathered rock is sound but weak, and highly weathered rock is unsound. At the quarry site, the rock is more siliceous and is free from intercalations of argillite. A similar relationship between weathering and soundness is evident here also, some of the moderately weathered rock may be satisfactorily sound,but the highly weathered rock crumbles and disintegrates in soundness tests (Wells and Findlay, 1971). Weathered greywacke in Brisbane has also failed tests for strength, abrasion resistance, and durability. The Stratford Quarry previously produced concrete aggregate from relatively fresh metagreywacke of the Barron River Metamorphics (Willmott and Muller, 1980). Other greywacke deposits near Cairns, investigated by Warner and Findlay (1973), are potential sources of aggregate also. In the Gladstone area, relatively hard metagreywacke of the Berserker Beds has been worked for railway ballast at the Yarwun Quarry. It is reported to be of good quality but has a slight tendency to flaky particle shape. The Catfish Creek Quarry produced ballast from hard, fresh to slightly weathered greywacke of the Mount Holly Beds. The rock is sheared and its use was discontinued because the aggregate failed the severe particle shape specifications (Holmes, 1980a). CONGLOMERATE Deeply weathered sandy conglomerate of the Woogaroo Sub-Group is worked for concrete aggregate at the CBR Calamvale Quarry. The conglomerate is relatively free from clay and disintegrates readily. The material is popular for exposed aggregate and for decorative work because of a predominance of white opaque quartz pebbles. The occurrence is unusual in that most Mesozoic conglomerates in the Moreton Region are well indurated, have a high clay content, or contain pebbles that are too weak for use as aggregate (Willmott, 1979). LIMESTONE Limestone of the South Curra Limestone is crushed for road screenings at the Curra Quarry, and concrete aggregate is produced from limestone of the Calliope Beds at the Taragoola Quarry. Limestone is used extensively for aggregates overseas,but has had little use in Queensland. Limestone is comparatively soft, has low resistance to impact, and is susceptible to polishing in use as road sealing aggregate. It is also susceptible to attack by some groundwaters. Dolomitic limestone should be selected for concrete aggregate with caution because of its tendency towards alkali reactivity. Limestone is specified in some specialised concrete uses, however, because of its low co-efficient of expansion.

The agg rega te crus hing and Los Ang eles abra sion valu es obta ined in tes ts on lime ston e from the· Cur ra and Tar ago ola Qua rrie s are high rela tive to othe r rock type s but are with in the lim its spe ci f ied for den se nat ura l agg rega (Sta nda rds Ass ocia tion of Aus tral ia, tes 197 4). The lime ston e at Tar ago ola has been foun d to be uns uita ble for use as bitu men scre enin gs by the Mai Roads Dep artm ent beca use of its sus n cep tibi lity to pol ishi ng. The gre ater stre ngt h and high er poli she d ston e valu e of lim esto ne at the Cur ra Qua rry, and esp ecia lly at the near by Cor ella Ridg e dep osit , illu stra te the ben efic infl uen ce of sili ceo us imp urit ies ial on the pro per ties of lim esto ne for agg rega te. RIVER GRAVEL Riv er gra vel is sti ll the maj or sou rce of con cret e agg rega te for Bris ban e and is a maj or sou rce for the Gol d Coa st and Cai rns. It is a min or to sig nifi can t sou rce for sev eral coa stal tow ns betw een Cab oolt ure and Tul ly, and is also used in the Bowen Bas in and on the Ath erto n Tab lela nd. The re are 49 wor king s known to be prod ucin g allu via l gra vel in Que ensl and , mos sole ly for con cret e agg rega te. tly Cha nne l dep osit s of rive r gra vel norm ally req uire neit her stri ppi ng of ove burd en nor reh abi lita tion and are recon omi cal to wor k. The oth er type s of gra vel dep osit wor ked in Que ensl and are allu via l terr ace s, gra vel bar s, and poi nt bar s. Bec ause of the div ersi ty of the con stit uen t rock type s and the ir pro por tion s, gra vels gen eral ly do not exh ibit a con sist ent pat tern of phy sica l pro per ties from one loc alit y to ano ther . Tra nsp ort of the bed load tend s to remove the wea ker con stit uen ts by attr itio n, but gra vel dep osit s nev erth eles s may be con tam inat ed by par tly wea ther ed, sof t, or foli ated rock s. All uvi al gra vels may also be con tam inat ed by coa ting s of clay and oth er del eter iou s mat eria ls, but mos t of thes e can be rem oved by was hing . A wor kab le con cret e agg rega te of low cem ent requ irem ent is obta usin g roun ded , smo oth- text ured rive ined r gra vel , but the text ure and par ticl e shap e are res tric tive in spe cial ised app lica tion s such as high stre ngt h con cret e. Unc rush ed allu via l gra vels are uns uita ble for use as road sea ling agg rega te beca use of the effe ct of par ticl e surf ace text ure on the fric tion al pro per ties and on bitu men adh esio n. The agg rega te reso urce s of the Bris ban e Riv er and of the Pine Riv ers are des crib ed by Holmes (198 0b) and by Hofmann (198 0). The Bris ban e Riv er sup plie s the cen tral and sou ther n met rop olit an mar ket more eco nom ical ly than any othe r ava ilab ie sou rce of agg rega te. The Pine Riv ers area con stit ute s a maj or reso urce with rese rve s of agg rega te now exc eed ing thos e of the Bris ban e Riv er; it gen eral ly sup plie s the nor ther n par t of the Bris ban e Sta tist ica l Div isio n. Both reso urce s are def icie nt in coa rse agg rega te and are poo rly grad ed. Ove rsiz e gra vel is crus hed , and crus hed qua rry rock is requ ired to supp lem ent des ired grad ing lim its. The two reso the rive r agg rega te to ach ieve mos t urce s have sim ilar sou rce rock s, and both are used sole ly for con cret e agg rega te. The ind ustr y gen eral ly con side rs the Bris ban e Riv er gra vel to be sup erio to the Pine Riv ers gra vel in stre ngt r h, par ticl e shap e, dur abi lity , and con tent of del eter iou s mat eria ls. The agg rega te crus hing and flak ines s inde x tes t res ults on scre enin gs prod uced from the Bris ban e Riv er by the maj or sup plie rs atte st to the stre ngt h and roun dne ss of the gra vel. Sou ndn ess tes t data on Bris ban e Riv er gra vel are not ava ilab le,b ut Hofm ann (198 0), in com pari ng the two reso urc es, rep orts tha t unso und par ticl es in the bed load of the Bris ban e Riv er are elim inat ed thro ugh long er tran spo rt. A pet rolo gic al ana lysi s of a random sam ple of Bris ban e Riv er gra vel by

Holmes (1980b) gave 28 per cent metasedimentary and sedimentary rocks, 26 per cent andesitic volcanics, 22 per cent chert and jasper, 13 per cent quartzite and 11 per cent quartz. In general, the Pine Rivers aggregate is considered to be suitable for a variety of purposes but is not of top quality. The aggregate properties of gravel of the Strathpine terrace and the channel of the South Pine River are described by Hofmann (1980). The general requirements for dense natural aggregates (Standards Association of Australia, 1974) were met in most tests, the main deleterious property of the aggregate being the marginal soundness of some of the constituents of the gravel. The main components of the gravel of the North and South Pine Rivers are quartz, chert, quartzite, greywacke, indurated siltstone and schist, with lesser amounts of intrusive and volcanic rocks. Slate, phyllite, shale, and some basalt clasts tend to break down unde~ chemical weathering, resulting in the marginal sodium sulphate soundness test values. The gravel of the Coomera River between the Pacific Highway and Wongawallan Creek consists dominantly of greywacke and chert (Cooper and Master, 1976). This resource is important because of the quality of the gravel, the low proportion of fines, and its location close to the Gold Coast market. The gravel of the Mulgrave and Little Mulgrave Rivers consists of a large proportion of basalt compared with that of other streams in the Cairns district, where metamorphic rocks give rise to flaky particles unsuitable for concrete aggregate. The crushing plant used is, however, the impactor type, which produces aggregate of acceptable shape from the component of gravel comprised of metamorphic rock types (Willmott and Muller, 1980). CONCLUSIONS Queensland is fortunate in its distribution of suitable rock types and gravel in the populous regions. River gravel is one of the most widely used sources of aggregate and is preferred for use in concrete because of its economy and quality. Basalt is the most widely available quarry rock and, where unweathered, unaltered, and non-vesicular, it provides an excellent aggregate. Rhyolite and other acid to intermediate volcanic rocks are also widely available, but exhibit variation in strength, durability and alkali reactivity. The intrusive rocks quarried include granite, adamellite, granodiorite, microgranite, granophyre, microdiorite, trachyte, and dolerite. All are sources of economical, strong, sound and durable aggregates provided that they are closely jointed, unweathered, of uniform petrology, and free of excessive amounts of deleterious alteration minerals. The metamorphic rocks vary widely in character. Metagreywacke and massive greenstone may provide aggregate of good quality, quartzite and hornfels need careful evaluation,and other metamorphic rocks are foliated and weak, resulting in aggregate of poor particle shape, poor durability, and low strength. In general, all sedimentary rocks, except impure limestone and those that are exceptionally indurated, are suspect as sources of aggregate. This review does not identify serious deficiencies in the suitability or regional availability of natural aggregates in Queensland. However, improved quarrying practice is required to reduce the use of weathered rock and · correct the particle shape of some aggregates. Investigations of the properties of aggregates of marginal quality are needed to define their

58 suitab ility for specif ic uses more accura tely. In partic ular, resear ch is needed on the aggreg ate source s suspec ted to be alkali reacti ve and on aggreg ates contai ning delete rious altera tion miner als. REFERENCES BARKER, R.M., 1976a: Marooc hy water supply - Coolo olabin damsi te, geolog ical report . Geolo gical Survey of Queens land, Record 1976/2 2 (unpu blishe d). BARKER, R.M., 1976b: Hay Point breakw ater, geolog ical report on propos ed quarry site. Geolo gical Survey of Queen sland, Record 1976/3 6 (unpu blishe d). BARKER, R.M., 1979: Gladst one water supply , geolog ical reconn aissan ce of Police Creek damsi te. Geolo gical Survey of Queen sland, Record 1979/4 3 (unpu blishe d). BARKER, R.M., and HOFMANN, G.w., 1973: Gunpowder Creek damsi te, prelim inary geolog ical report on the 109.0 km damsi te. Geolo gical Survey of Queen sland, Record 1973/2 1 (unpub lished ). BASFORD, G., 1975: Evalu ation of mater ials from Brisba ne City Counc il quarry , Hawke sbury Road, Moggi ll. Main Roads Depart ment Mater ials Branch , R 725 (unpu blishe d). BELL, G., 1977: Method s of explo ration and evalua tion of quarri Wylde, L.J., (edito r): Procee dings of the worksh op on the geologes; in y of quarri es, ARRC, Februa ry 1977. Austra lian Road Resear ch Board, Resear ch Repor t ARR 80, 95-113 . COLE, W.F., 1976: Testin g of basalt aggreg ate for concre te; in Confer ence on the produ ction, prope rties, and testin g of aggreg ates, Sydney . Unive rsity .of New South Wales, School of Highway Engin eering , 1976-0 9, 93-109 . COLE, w.F., 1977: Weath ering of rocks; in Wylde , L.J., (edito r): Procee dings of the worksh op on the geolog y of quarri es, ARRC, Februa ry 1977. Austra lian Road Resear ch Board, Resear ch Repor t ARR BO, 55-79. COLE, W.F., 1979: Dimen sional ly unstab le grey basalt s. Concr ete Resear ch, 9(4), 425-43 0.

Cement and

COLE, W.F., and BERESFORD, F.D., 1976: Evalua tion of basalt from Deer Park, Victo ria, as an aggreg ate for concre te; a progre ss repor t. Procee dings of the Eighth Austra lian Road Resear ch Board Confer ence, Perth, 8(3), 23-33. COLE, W.F., and LANCUCKI, c.J., 1976: Forma tion of clay miner als in basalt s. Paper presen ted at the sixth confer ence of the Austr alian Clay Miner als Societ y, Sydney (unpu blishe d). COOPER, w., and MASTER, R., 1976: Valley , Mauds land to Hope Island . 1976/2 0 (unpu blishe d).

Sand and grave l resour ces of the Coomera Geolo gical Survey of Queen sland, Record

DAVIES, A.L., and McINTYRE, G., 1979: Repor t on Petrie Quarry (Farle y and Lewers ) mater ials invest igatio n. Main Roads Depart ment Mater ials Branch , R 969 (unpu blishe d).

59 DENARO, T.J., 1977: Reedy Creek scheme, preliminary geological report. Geological Survey of Queensland, Record 1977/21 (unpublishe d). FINDLAY, J.K., 1975: Mackay water supply, geological report on Dumbleton Rocks damsite. Geological Survey of Queensland, Record 1975/28 (unpublishe d). GORHAN, H.L., 1971: Funnel Creek damsite. Preliminary geological report. Geological Survey of Queensland, Record 1971/10 (unpublishe d). HOFMANN, G.W., 1980: Aggregate resources of the Pine Rivers area. Geological Survey of Queensland, Publication 375, 9-22. HOLMES, K.H., 1980a: Constructio n materials in the Gladstone area. Queensland Government Mining Journal, 81(943), 267-272. HOLMES, K.H., 1980b: Aggregate resources of the Brisbane River between the Bremer River and the Captain Cook Bridge. Geological Survey of Queensland, Publication 375, 1-7. LAYCOCK, J.W., 1963: Caloundra boat harbour investigatio ns, geological report No. 2. Geological Survey of Queensland, unpublished file report. MANION, J.E., 1966: Report on North Pine Dam concrete tests. of Local Government, unpublished report.

Department

MARTIN, J.E., 1979: Quarry rock investigatio n, State Forest 611, Beerwah. Geological Survey of Queensland, Record 1979/40 (unpublishe d). MARTIN, J.E., 1981: Properties of Queensland aggregates. Survey of Queensland, Record 1981/29 (unpublishe d).

Geological

NYOEGER, E., 1978: Quality of stone, Internation al Training Course in road and bridge engineering for African and Asian engineers. Reference papers, Volume 6. Country Roads Board of Victoria (unpublishe d). O'FLYNN, M.L., 1979: Reconnaissa nce of extractive resources in the Caboolture Shire. Geological Survey of Queensland, Record 1979/2 (unpublishe d). SHIPWAY, C.H., 1961: Bruce Highway No. 49 - Burpengary- Landsboroug h Road materials survey. Geological Survey of Queensland, unpublished file report. SHIPWAY, C.H., 1962: Roma district - inspection of basalt deposits. Geological Survey of Queensland, unpublished file report. STANDARDS ASSOCIATION OF AUSTRALIA, 1974: Dense natural aggregates for concrete. Australian Standard, 1465-1974. TREZISE, D.L., 1978: Reconnaissa nce of extractive resources in the Noosa Shire. Geological Survey of Queensland, Record 1978/27 (unpublishe d). WARNER, K.R., 1962: Main Roads Department No. 1 District, Pine Rivers Shire - materials survey. Geological Survey of Queensland, unpublished file report. WARNER, K.R., 1972: Kingaroy Shire quarry investigatio n, geological reconnaissa nce. Geological Survey of Queensland, Record 1972/3 (unpublishe d).

60 WARNER, K.R. , 1975 : Thur sday Islan d quar ry inve stiga tion , preli mina ry geol ogic al repo rt. Geol ogic al surv ey of Quee nslan d, Reco rd 1975 /31 ( unpu blish ed) . WARNER, K.R. , 1976 : Geol ogic al reco nnai ssan ce of Buru a Quar ry, Glad stone . Geol ogic al Surv ey of Quee nslan d, Reco rd 1976 /1 (unp ublis hed) . WARNER, K.R. , 1977 : Glad stone wate r supp ly - geol ogic al repo rt on prop osed rock fill darn on Boyne Rive r. Geol ogic al Surv ey of Quee nslan d, Reco rd 1973 /7 (unp ublis hed) . WARNER, K.R. , and BARKER, R.M. , 1979 : Taro ng power stati on site , geol ogic al reco nnai ssan ce of sour ces of cons truct ion mate rials . Geol ogic al Surv ey of Quee nslan d, Reco rd 1979 /12 (unp ublis hed) . WARNER, K.R. , and FINDLAY, J.K. , 1973 : Copp erlod e Fall s dam site, geol ogic al repo rt. Geol ogica l Surv ey of Quee nslan d, Repo rt 78. WELLS, B.E. , and FINDLAY, J.K. , 1971 : Albe rt Rive r dam site, preli mina ry geol ogic al repo rt, Volume 1. Geol ogica l Surv ey of Quee nslan d, unpu blish ed file repo rt. WILLMOTT, W.F. , 1978 : Reco nnais sanc e of extr activ e reso urce s in the Maro ochy Shir e. Geol ogic al Surv ey of Quee nslan d, Reco rd 1978 /13 (unp ublis hed) . WILLMOTT, W.F. , 1979 : Rock cons truct ion mate rials in the east ern More ton regio n, revie w of prod uctio n and reso urce s. Quee nslan d Gove rnme nt Mini ng Jour nal, 80(9 34), 393- 418. WILLMOTT, W.F. , 1980 a: Work ings of cons truct ion mate rials on the Athe rton Tabl eland . Quee nslan d Gove rnme nt Mini ng Jour nal, 81(9 49), 552- 564. WILLMOTT, W.F. , 1980 b: Work ings of cons truct ion mate rials in the Ingha mTull y-In nisf ail area . Quee nslan d Gove rnme nt Mini ng Jour nal, 81(9 46), 390- 406. WILLMOTT, W.F. , and MULLER, P.J. , 1980 : Work ings of cons truct ion mate rials in the Cairn s-Mo ssma n area . Quee nslan d Gove rnme nt Mini ng Jour nal, 81(9 45), 355- 365. WYLDE, L.J. , 1975 : road cons truct ion.

Lite ratu re revie w: crush ed rock and aggr egate for Aust ralia n Road Rese arch Boar d, Rese arch Repo rt ARR 43.

WYLDE, L.J. , 1976 a: Repo rt on field work i Quee nslan d and New Sout h Wale s, 6-19 th November 1975 . Aust ralia n Road Rese arch Boar d, Inter nal Repo rt AIR 172- 1 (unp ublis hed) . WYLDE, L.J. , 1976 b: In-se rvice dete riora tion of road aggr egat es. Aust ralia n Road Rese arch Boar d, Inter nal Repo rt AIR 172- 2 (unp ublis hed) . WYLDE, L.J. , 1976 c: Anal ysis of a ques tionn aire on the serv ice perfo rman ce of crush ed rock and aggr egat e. Aust ralia n Road Rese arch Boar d, Rese arch Repo rt ARR 61. WYLDE, L.J. , 1976 d: Repo rt on the firs t ARRB work shop on crush ed rock and aggr egat e, 15th Octo ber 1975 . Aust ralia n Road Rese arch Boar d, Rese arch Repo rt ARR 53. WYLDE, L.J. , 1979 : Marg inal qual ity aggr egat es used in Aus trali a. Aust ralia n Road Rese arch Boar d, Rese arch Repo rt ARR 97.

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