Seismic Stratigraphy Of The Tertiary Sediments In The Sedimetology And Diagenesis Of Sandstones Within The Lower Jurassic Cattamarra Coal Measures, North Perth Basin, Western Australia.
Tarabbia, Paul Joseph
Honours Degree, 1991
University of Adelaide
The sandstones of the Lower Jurassic Cattamarra Coal Measures were deposited within a developing rift basin in fluvial-lacustrine environments. These fine to coarse-grained sandstone units were deposited in upward-fining distributary channel fills within fluvial braided-meander-paludal complexes. The bulk of the core samples are texturally and mineralogically immature subarkoses, deposited rapidly and near to a cratonic igneous/metamorphic source terrain.
Three main stages of diagenetic alteration can be identified. Early diagenesis was controlled by near surface and shallow meteoric waters. Etching of framework quartz, early grain coating cements, compaction, quartz overgrowths and calcite cementation characterise this phase. The intermediate stage was marked by the dissolution of calcite and the precipitation of authigenic chlorite and kaolinite by acidic basinal brines. Late stage diagenesis was associated with deep burial and is represented by secondary porosity from the dissolution of feldspar and calcite, suturing of quartz grains and authigenic illite development. Authigenic elay minerals were studied using x-ray diffraction, optical microscopy and the scanning electron microscope.