EARLY JURASSIC DELTAIC DEPOSITION OF COAL, PERTH BASIN, WA

The Early Jurassic coal of Cattamarra Coal Measures occurs in the Hill River area which is located approximately 280 km north of Perth in the northern Perth Basin of Western Australia. On the basis of petrological study the coal is banded, dull banded and dull lithoypes with minor bright banded, bright and fusainous types. The maceral composition of coal is dominated by vitrinite and inertinite group of macerals, whilst the exinite and mineral matter are in minor amount. The presence of framboidal pyrite of bio-genic origin in the coal has a significanct influence in the depositional environment of coal, and the interaction between microbial ( bacteria ) geochemical and parent vegetation of the coal.

The petrological, geochemical ( trace elements), sedimentological and palynological( acritarchs )studies of the coal support the depositional environment as an upper to lower delta type with a regressive phase of marine transgression.