The Permian coal in the Muja Coal Measures of Collie Basin of Western
Australia has a subdued lustre because of the fine laminations of
lithotypes, and the dominance of dull and dull banded lithotypes with
minor bright, bright banded and fusinous types. The maceral composition
of the coal is variable, however the macerals of vitrinite and inertinite
groups dominate and the exinite and mineral matter contents are low. The
lithotypes have low concentrations of trace elements and the boron
concentration is between 10 - 100 ppm recorded only from the dull
lithotypes. On the basis of organic petrology, the inter-seam sediments,
flora and the very low concentration of boron, the depositional
environment postulated for the coal is braided, fluvial and
fluvio-lacustrine with marked fluctuations in the water table. The low
water table in the environment accounts for fusain and inertodetrinite in
the coal.