‘Look around you - all you can see is really there. Yet, behind each thing lies a mystery, hidden from view. If you try hard, you may get a glimpse of that world, but never will you be able to see it all’. Life as a Geological Force - Dynamics of the Earth’, by Peter Westbroek, W.W. Norton & Company, 1991. I rediscovered this quote in a book I had bought years ago, when I had just started my new job as a ‘Geoarchaeology Technician’ at the University of Cambridge. After working nearly ten years as part of a small team in an archaeological rescue unit, I was asked to join the new science movement at the Department of Archaeology with Dr Charles French. My real reasons for change were due to the strong feeling that there was more to investigating the past than using a trowel, and that the answers I was seeking were in the soil and sediment that I dug away. When I went to dig a site, I began to think; ‘where does the archaeology really begin – does a history start in the layers of soil above and below where we are looking for the material evidence of the past? Can we pick up the imprint of ancient landscapes and the signatures of human interaction with the earth? Can we pick up the physical “memories” left behind by people long ago?’ These very thoughts have kept my hunger and enthusiasm for Geoarchaeology fuelled for fifteen years. There isn’t a day that passes, that I don’t revel in the delight of looking down my microscope. I have watched the fields of Archaeology, Geography, Biology, Zoology, and Earth Sciences conjoin in a most marvellous way. The tools we are now able to use to unravel the past are exquisite, and the answers they give us are intimate and powerful. Soil micromorphology can offer the ability to pickup ‘rainfall sequences’ on the floor rubble of an abandoned and collapsed mudbrick house from Neolithic Turkey, as evidenced in Dr Wendy Matthew’s poster. In Dr Gillian Wallace’s poster from Lac Du Chalain, France, we are able to view the seeds, cereal grains, the woods and charcoals - the very movement of the water itself in the debris left behind by people living near and over the lake in the Neolithic. You are invited in Dr Steve Boreham’s and my poster to stretch your imagination to the warm, lush interglacial environment of Britain over 700,000 years ago at Pakefield, Suffolk, where layers of rich organic muds and sands were laid down on a marshy floodplain intersected by river channels and frequented by animals and people. In ‘Hidden Worlds’, I would like to invite the viewer to see the extraordinary - the detailed stories that are not normally seen or told within the confines of standard archaeological field practice. As an observer, you are given the opportunity to explore the depths of ancient cave sites in the far-off places of Chile, Argentina, and Borneo. You can look into the refuse of a Neolithic waste dump from archaeologyrich Wiltshire, UK. You can step into a Viking household in Norway, or gaze at Mayan agricultural fields in the highlands of Peru. These are just some of the vast worlds a geoarchaeologist is privileged to visit.
Soil micromorphology, although time-consuming and labour intensive can sharpen, bring forward and separate the threads that makeup the tapestry of the past. The world is changing at a remarkable and sometimes frightening rate. It is possible to see in this show, that through renewed energy and responsibility for guardianship of the earth we can continue to look through the looking glass of deep-time and perhaps bring some of that understanding to use in bettering our future. Julie Boreham - June 2008 Note: Each poster image in this exhibition has a public description, and a scientific description for the professional practitioners in the field. The title of the scientific micromorphology description is italised, unless the contributor chose to combine the two methodological approaches. The public is invited to read both. I would like to dedicate the ‘Hidden Worlds Exhibition’ to the memories of two very special women, Anne McBurney and Jane Forbes. Both women helped to remind me that I had a voice to be heard and an art to share. And to my husband, there are no words to say… and to all my daughters, my love. Frontispiece: The Ancient Saar Project, London-Bahrain Archaeological Expedition This image was taken from a slide donated by Dr Wendy Matthews, Department of Archaeology, School of Human and Environmental Sciences, University of Reading. As a Geoarchaeology specialist, she was part of the Saar excavation team from 19931995. The London-Bahrain Archaeological Expedition was formed in 1989 to contribute to the archaeology of the Arabian Gulf by excavating a settlement of the so-called Early Dilmun period in Bahrain. On the basis of pottery comparisons, the duration of the settlement is estimated to be about 250 years, from 2100 to 1850 BC. Our understanding of the country at this early time had depended largely on robbed tombs and isolated religious sites, and lacked information on how the islands people interacted with their environment and their neighbours, how they harnessed their resources, what they ate, how their society worked and how they actually lived. The excavations at Saar, Bahrain, took place between 1990 and 1999. The UK academic supporter of the project was the Institute of Archaeology, University College, London. In Bahrain, the Expedition received the patronage of the Amir, the late Shaikh Isa bin Sulman Al-Khalifa. The project was funded mainly by the business community in Bahrain, as well as by the British Academy and other academic funding bodies. The directors were Robert Killick, Jane Moon, and Harriet Crawford (for the period 1990-5). Dr Robert Killick 2007. Abridged from the Archaeological Data Service; http://ads.ahds.ac.uk/
Exhibition catalogue An Archaeology of Surfaces: Life-histories of buildings at the Neolithic site of Çatalhöyük, Turkey. Dr Wendy Matthews, Department of Archaeology, School of Human and Environmental Sciences, The University of Reading These thick orange and brown mud-plaster floors closely resemble those from a flat roof/upper storey, which had a collapsed into an abandoned building, Building 3, BACH Area. These surfaces are thicker than those laid on ground-floors within the buildings at Çatalhöyük. In this building, Building 5, these surfaces had been broken up into large aggregates and used to infill the ground floor rooms to provide a stable foundation for construction of a later building. In this intact sequence of mud-plaster floors, the surfaces bear the traces of matimpressions, irregular abrasion and lenses of occupation ‘dust’, less than 2 mm thick. Towards the end of this sequence, there are several layers of undisturbed water-laid crusts, which suggest the building started to fall into disrepair and may have been abandoned for sometime, before it was finally dismantled. The absence of rain or wind-laid deposits throughout most of the earlier sequence suggests that this area was itself roofed, and was probably an upper-storey room, probably above the ladder entrance. Dismantled flat-roof/upper-storey floors in room-fill, Building 5, Space 154, North Area, Level VII/VIII The mud-plaster floors were made from poorly to moderately sorted silty clay loam to sandy silt loam sediments, ranging from greyish brown to yellowish brown and orange in colour. The coarse material includes quartz, feldspar and carbonate minerals, up to 0.7 mm in size. The fine material is mineral with a crystallitic birefringence fabric. Some plasters include intact aggregates of oxidised alluvium. Many mud-plasters include: 2-5% charred flecks; <2% burnt aggregates, and sparse burnt and non-burnt bone, less than 2mm in size, incorporated into the plaster during manufacture. Inclusions are generally unoriented and randomly distributed in each mud-plaster layer. Linear and curvilinear impressions of plant remains, 2 10%, up to 8mm in length, are randomly distributed and strongly oriented parallel to the floor surfaces. These originally fresh plant remains were probably added as stabilisers to provide tensile strength and flexibility. The related distribution between the coarse and the fine material is embedded, from mixing, pugging, laying and smoothing of the mud-plasters. The upper boundaries of the mud-plasters vary from smooth and undulating, with probable mat impressions, to irregular and slightly truncated. Accumulated lenses of occupation residues are rare, and only < 2 mm thick. These comprise sandy loam with: up to 30% charred plant remains, 2-5% phytoliths, ash, <2 % bone, rounded aggregates, and sparse organic staining, all < 2mm in size.
There are 7 lenses of well-sorted sandy loam to silt clay with: strong parallel basic and referred orientation, linear basic and referred distribution, embedded graded bedding, up to 0.7 mm thick, of water-laid deposition. These lenses include flecks of charred plant remains. There is some distortion and cracking, but the lenses are intact. Post-depositional alterations are localised and include: vertical cracks, particularly in the earlier plasters with fewer plant stabilisers; channels and chambers from bioturbation; and very sparse reprecipitated gypsum salts. Original glass thin-section size: 137mm x 67mm x 3mm.
Fine Layers from a Prehistoric Cemetary Sequence from Niah Cave, Borneo, Malaysia. Dr Helen Lewis, School of Archaeology, University College Dublin, Ireland. The layers in this thin-section are primarily composed of guano, with a variety of colours resulting from a number of diagenetic processes. Bone fragments are frequently seen; these are of the right size to be from swiftlets or small mammals, probably bats. A layer rich in mollusc shells represents one of several small ‘clumps’ of shells found across the upper exposed layers of the cemetery. In thin-section, this layer is intermixed with charcoal and some possible wood ash. A thin reddish layer at the base of the shells also contains possible ash, and overlies a thin dark layer, which is composed primarily of charcoal with rare burnt bone remains. These layers appear to represent an in situ hearth or firing event, apparently related to cooking; whether this is simply occupation activity or ceremonial activity associated with the cemetery is unclear. A second series of hearth deposits dominates the middle of the slide, composed of charcoal, ash and oxidised sediment. There are several guano layers, reworked by faunal activity, and including frequent bone, charcoal remains and red clay-rich aggregates from elsewhere in the cave system. One thin white layer was identified as possible cloth in the field. In thin-section, this ‘cloth’ layer is composed of currently unidentified authigenic minerals, overlying another thin layer of charcoal. Bodies wrapped in cloth along with several types of cremation burial are seen in the cemetery sequence. It is possible that this small sequence is related to burial practice. Acknowledgements. Evans Fund, British Academy CSEAS, Niah Cave Project, Dr. Steve Boreham, Prof. Graeme Barker, Dr. Charles A.I. French, Dr. Mark Pollard, Dr. Chris Doherty, University of Cambridge, Department of Archaeology and Department of Geography, Oxford University Research Laboratory for Archaeology and the History of Art. Original glass thin-section size: 137mm x 67mm x 3mm.
Late Neolithic Village Remains on the Lac de Chalain, France. Dr Gillian Wallace. The McBurney Geoarchaeology Laboratories, Department of Archaeology, University of Cambridge, UK. Farmers in the Neolithic age frequently settled around lakes in the circum-Alpine region, as well as wetlands elsewhere. This particular sample is from one such village, Site 19 from the Lac de Chalain in France. Lakeside villages offer excellent preservation, and this particular slide is striking in that charred cereal grains are clearly visible in addition to fragments of wood. The lighter substrate is lake marl, which is also the overlying sediment. Between 3200 â€“ 3000 BC, the usual duration of settlements was around 12 years. The lack of artefacts at this particular level indicates that the settlers may have intentionally burnt their buildings so to discourage interlopers from occupying the space. Late Neolithic Village Remains on the Lac de Chalain, France. Site 19, Slide 7, France. Horizon
% Void Space
5 (top) 4
Lake marl Orientated organicsedimentary mix Organics with little matrix
Orientated organicsedimentary mix Lake marl
Ratio Coarse: Fine
% Mineral Components 65 40
Inter-grain microaggregrate microstructure Complex
Charred wood and cereal grains
Acknowledgements. Anne-Marie and Pierre PĂŠtrequin, CNRS, for permission to take and analyse the sample; German Academic Exchange Service (DAAD) for funding. Original glass thin-section size: 137mm x 67mm x 3mm.
A House Floor from Kaupang: the Earliest Town in Norway. Dr Karen Milek, Department of Archaeology, University of Aberdeen, UK. This thin section was taken from the floor of a Viking Age building. The layer of reddish-brown clayey aggregates near the top of the thin section is the clay hearth in the centre of the building. The layer has been badly disturbed by soil fauna. Below this, there is a dark-brown, organic-rich, charcoal-rich, sandy sediment typical of most of the floor layers on the site. This floor deposit contains small fragments of burnt and unburnt bone, which suggested that the building was used for domestic activities such as cooking and eating. Below the floor layer there is a lens of charcoal. This was probably derived from intentionally dumped wood ash, but the silty grey component of the ash (calcium carbonate) has been leached away.
Acknowledgements. The urban settlement of Kaupang, on the shores of the Viksfjord in southern Norway was excavated in 2000-2002 by Dagfinn Skre, at the University of Oslo. The anthropogenic sediments making up the site were analysed by Karen Milek and Charles French at the University of Cambridge. Milek, K. and French, C. (2007) Soils and sediments in the settlement and harbour at Kaupang. In D. Skre (ed.), Kaupang in Skiringssal. Aarhus: Aarhus University Press. Pp. 321360. Original glass thin-section size: 137mm x 67mm x 3mm.
A Late Neolithic Midden Deposit from Durrington Walls Henge, Wiltshire, UK. Dr Charles French. The McBurney Geoarchaeology Laboratories, Department of Archaeology, University of Cambridge, UK. This slide was taken through the later Neolithic midden deposit that had accumulated on the earlier Neolithic rendzina soil, all buried beneath chalk rubble erosion slip from the Durrington Walls henge bank, just near its eastern entranceway. The midden is largely composed of wood ash with large amounts of bone fragments. There are several interruptions evident in its accumulation, suggesting an episodic accumulation history.
Durrington Walls 2007. This sample is a midden accumulation built-up on the buried soil preserved beneath the slumped chalk of the henge bank at Durrington Walls' eastern entranceway. The midden material is primarily comprised of calcitic ash with greater and lesser amounts of finely comminuted charcoal, or wood ash, abundant charcoal fragments from silt to small pebble size, some amorphous iron impregnated/oxidized plant tissue and variable quantities of large and small fragments of burnt and unburnt bone. These deposits exhibit at least three distinct horizons, with denser zones of compacted fabric (over 2-5mm) evident towards the top of these horizons, perhaps indicating compacted/trampled surfaces. Acknowledgements. The soils work at Durrington Walls is part of The Stonehenge Riverside Project under the direction of Professor Mike Parker Pearson of the University of Sheffield, which is funded by the Arts and Humanities Research Council, with funding also received from the McDonald Institute for Archaeological Research, University of Cambridge. Original glass thin-section size: 137mm x 67mm x 3mm.
Lanashuaia Cave, Bay of Cambaceres, Beagle Channel, Tierra Del Fuego, Argentina. Prof Marco Madella, ICREA, Research Professor in Environmental Archaeology, Director of the Laboratory for Palaeoecology and Plant Paleoeconomy. Institucion Mila y Fontanals, ESPAÑA. Dr Charles French. The McBurney Geoarchaeology Laboratories, Department of Archaeology, University of Cambridge, UK. This slide represents different dumping episodes in an earlier 20th century Yamana midden deposit composed of largely organic material overlying a mixed deposit of fine stones and organic matter, severely bioturbated by the soil faunal since deposition. Lanashuaia Cave Deposits 2007, Sample 2. Bay of Cambaceres, Beagle Channel, Tierra Del Fuego, Argentina. This sample is comprised of three fabric units. The lower fabric unit 1 (8-13cm) is composed of pellety, amorphous, black organic matter (30-65%) inter-leaved with plant tissue fragments which are partially replaced by amorphous iron and/or clay, and 35-70% fine, lenticular to sub-rounded, stone fragments (<2cm). The middle fabric unit 2 (2.5-8cm) is composed of black to reddish black, amorphous, pellety organic matter (80%), minor amounts of very fine and fine quartz (5%) and very fine (<8mm) stone fragments (<5%). The upper fabric unit 3 (0-2.5cm) is predominantly composed of fine angular stone fragments (<2cm in all orientations, 10% shell fragments, 5% micritic calcium carbonate and 20% pellety, amorphous, black organic matter. The latter unit exhibits a slightly lensed aspect. This material would appear to represent different dumping episodes of largely organic material overlying a mixed deposit of fine stones and bioturbated organic matter. Acknowledgements. This slide was taken as part of a larger project entitled ‘Evaluation of the potentialities of residual analysis as a approach to the integral study of lithic material: the application to an ethnoarchaeological case-study in Tierra del Fuego’. ‘Evaluación de la potencialidad del análisis de residuos en el marco de una propuesta integral de estudio del material lítico: aplicación a un caso etnoarqueológico en Tierra del Fuego’. Funding was provided by the Spanish National Research Council (CSIC), and the Argentina National Council for Scientific and Technical Research (CONICET). We would like to thank M. Alvarez, A. Vila, I. Briz and D. Zurro for help during the fieldwork and project administration. Original glass thin-section size: 137mm x 67mm x 3mm.
Pizzulic Site, Englefield Island, Magallanes, Chile. Dr Manuel A. Kalin, The McBurney Geoarchaeology Laboratories, Department of Archaeology, University of Cambridge, UK. In Southern Patagonia, ancient shell middens are dated as early as the 6th millennium BP, the height of the mid Holocene marine transgression. This timing is reflected in the elevation of these archaeological sites, generally over ten meters higher with respect to the present sea-level than shell middens of the last two millennia. Insular sites such as Pizzulic evidence the use of sea-worthy watercraft in what are undoubtedly extremely challenging conditions for navigation. Researchers believe the human communities responsible for these sites were hunter-gatherers specialized in the acquisition of maritime resources not unlike those recorded in ethnographic descriptions of the 19th and 20th century AD. The latter are known to have lived on and adjacent to large accumulations of shells, employing the latter as building materials for windbreakers. Whilst by definition shell middens concentrate large amounts of shells discarded after consumption of shellfish, it is important to state that their excellent preservation does not mean that the bulk of dietary requirements were met with shellfish! Bone of sea lions and fish are not uncommon in these sites and were most likely far more significant than shellfish. Pizzulic 2005, Profile 1.5. The thin section shows well-bedded fresh (purple, yellow, white) and burnt (light grey) shell fragments packed with sand to silt-sized crumbs of moderately organically-stained light brown clay, beach pebbles, charcoal fragments, fish bone, and rootlets replaced with calcium carbonate. At high magnification the soil material can be seen to embed a significant amount of silt-sized charcoal and microscopic bone fragments, in turn suggesting an origin in soils upon which people's debris was accumulating. Whilst the generally porous aspect of the thin section would suggest that these shells accumulated directly at the 'toss-zone' of ancient meals, it seems more likely that their ultimate resting place is an outcome of site maintenance practices in which shells were preferentially accumulated or remobilized to one or another place on site. Patterns of fragmentation - of shells and of charcoal fragments - indicate some trampling took place as they accumulated. Acknowledgements. The research which led to the study of the Pizzulic site is part of the Southern Patagonia Geoarchaeological Project, directed by M. Arroyo-Kalin and C. French (University of Cambridge). This research would not have been possible without the generous support of CHILE Projects, Centre for Latin American Studies, University of Cambridge; the Centro for Quaternary Studies of Fuego-Patagonia and Antarctica (CEQUA), Magallanes, Chile; the McBurney Geoarchaeology Laboratory, University of Cambridge; and the McDonald Institute for Archaeological Research, University of Cambridge. We would like to particularly thank Manuel San Romรกn, Pedro Cรกrdenas, Fabiana Martin, Alfredo Prieto and Flavia Morello for both making this research possible and for acting as co-partners in Chile for the Southern Patagonia Geoarchaeological Project. Samples have been collected with due authorization of the Chilean Consejo de Monumentos Nacionales. Original glass thin-section size: 137mm x 67mm x 3mm.
Cromer Forest Bed, Pakefield, Sufffolk. UK. Dr Steve Boreham, The Physical Geography Laboratories, Department of Geography, University of Geography. UK & Julie Boreham, earthslides.com, Cambridge, UK. This pair of slides is taken from a single block sample of the Cromer Forest Bed exposed in a sea cliff section at Pakefield, Suffolk. This site recently became famous for producing early Palaeolithic flint tools, which evidenced some of the earliest hominin activity in Europe. The warm, lush interglacial environment of Britain 700,000 years ago at Pakefield, produced rich organic muds and sands laid down on a marshy floodplain intersected by river channels and frequented by animals and people. Cromer Forest-bed Formation (‘rootlet bed’) The upper part of the Cromer Forest-bed Formation at Pakefield (the ‘rootlet bed’) comprises laminated alluvial overbank floodplain deposits. These laminated sands and silts represent cyclical flooding events, resulting in multiple fining-upwards sequences, each representing sedimentation during declining flood flow. Layers of fine-grained organic mud, were probably laid down in shallow pools on the floodplain. There is plastic deformation of some sediment layers (possible footprints) and occasional bioturbation. Rootlet channels are surprisingly rare, as are shell debris or charcoal. At the base of the sequence, there is modest erosion between flood events giving rise to ‘fluting or ‘ripple marks’. Towards the top of the sequence there is apparently little erosion between or during flood events, suggesting an increasingly distal position on the floodplain. Iron and manganese staining, replacing organic material in some places, is evident. At the top of the sequence, the iron staining does not always respect the stratigraphy. During the drying process, the sediment block split along several sandy laminae causing deformation cracking in the final thin section. Original glass thin-section sizes: 137mm x 67mm x 3mm.
Peruvian Agricultural Terrace Deposits Dr Melissa Goodman Elgar, Department of Anthropology, University of Washington, USA. Andean farmers built stone terraces in the highlands of Peru to facilitate crop production in their steep landscapes. Topography and harsh weathering make terrace soils highly variable from terrace to terrace. This subsoil has weathered rock and a very high clay concentration. Clay absorbs water in the wet season which is released as soils dry out. This helps crops dependent on rainfall to grow during the dry season. Cycles of wetting and drying contribute to the spectacular colors of this slide. Paca 1, 5F, 1995. Terrace Subsoil, Paca Valley, Peru. The microstructure is blocky, platy in well-developed peds. The composition is roughly 50:50 coarse rounded pebbles to fine material. The b-fabric is bright mosaic-speckled, red to yellow clay in an open, single-double porphyric related distribution. Laminated textural pedofeatures dominate the fine material as both in situ and reoriented domains indicating vertisol properties. Porosity is low and root is rare suggesting that this horizon limits root depth. Original glass thin-section size: 75mm x 50 mm x 1mm.
This exhibition was solely funded by
Julie Boreham Thin-Sections of Earth and Archaeological Materials, www.earthslides.com, firstname.lastname@example.org The production and design of the â€˜Hidden Worlds Exhibitionâ€™ was created by the partnership of Julie Boreham, www.earthslides.com, and Dr. Steve Boreham, The Physical Geography Laboratories, Department of Geography, University of Geography. UK. Thanks and gratitude is given to Dr. Helen Lewis, School of Archaeology, University College Dublin, Ireland, for permission to show the exhibition as part of DIG 2008, Developing International Geoarchaeology Session. WAC, Dublin 2008. Special Thanks to John Bashford and Ian Bolton, The Anatomy Visual Media Group, Department of Physiology, Development and Neuroscience, University of Cambridge, for their technological magic and support.