131 o Pleistocene • Miocene A Oligocene Figure 2 • *w • • A A oo ° ® Vi o 360 380 400 420 Tmax 440 460 480 Figure 3 I C7AE=n-alkanes/alkenes RVm= R Vm= 0.61 0.551 ' I ' i • i ' i 1 1 •> LUUJLUUJULlLlJlJUlJJUJUJLiJLULJUUJUJLUllJLU < < < < < < < < < < < < < < < < < < < < < < < < NOOOOT-CVJCO^irXDNOOOO^-CVJCO^iniDNOOOO OOO'-'-'-'-'-'-'-'-'-'-wwcvjrgcvjwcNjwcvjwco OOOOOOOOOOOOOOOOOOOOO A 4.31 ORGANIC PETROLOGY OF PERMIAN COAL, VASSE SHELF, PERTH BASIN, WESTERN ASUTRALIA. B. Santoso* and K.K. Sappal School of Applied Geology, Curtin University of Technology, Perth, Western Australia. Coal seams of economic significance and restricted to a stratigraphic interval of lower Permian age, occur in the Vasse Shelf, southern Perth Basin, Western Australia. The coal bearing sediments described as the Sue Coal Measures are widespread in subsurface over a length of 17 kms, at depths between 180 m and 450 m, Kristensen and Wilson ( 1986). The area is faulted block/graben lying between the Bunbury Trough to the east and the Dunsborough Fault to the west. The coal samples of a 230 m interval from the CRA borehole No.CPCH 1 have been studied for their petrology. The coal predominantly consists of dull, dull banded, and bright banded, with minor bands of banded and bright types. The coal has a high content of inertinite and vitrinite with low exinite and mineral matter. The mineral matter is dominated by pyrite and clay which are usually associated with inertinite and vitrinite. Coal ash ranges from 5% to 49%; specific energy varies from 17-31 MJ/kg; bed moisture ranges Geological Society of Australia Abstracts Number 32, Ballarat 1992 from 6% to 20%; volatile matters are 23%; sulphur contents vary from 0.5% to 1.4% and chlorite is about 0.01 % on a dry basis. The maximum reflectance of vitrinite of is between 0.58% to 0.63%. So, based on these values, the Vasse Shelf coal is of sub-bituminous A rank of the ASTM Classification. The environment of deposition postulated for the coal measures is essentially point bar deposits whereas, the depositional environment of coal is mixed consisting of dry forest moor to open moor conditions. Reference Kristensen, S.E. and Wilson, A.C., 1986. A review of the coal and lignite resources of Western Australia. Proc. 13th. Congr. Min.&Met. Inst. 2, 87-97.