Glaucony As An Environmnetal Indicator, With Examples From The Cretaceous Of The Northern Carnarvon Basin, Western Australia.
Quinn, Matthew J.
Honours Degree, 1997
University of Adelaide
The aim of the study was to investigate the degree to which glaucony, from within the M. australis Sandstone Member of the Muderong Shale in the Barrow and Dampier sub-basins, can he used to define the environment of deposition. Using this information, the degree to which glaucony can be used to support a sequence stratigraphic framework was to be investigated.
Twenty-four samples were analysed from the Cherring #l, Wandoo #3, Centaur #1 and Saffron #1 wells.
Glaucony composition, morphology and internal structure were analysed using transmitted light microscopy, scanning electron microscopy, x-ray diffraction and electron microprobe techniques.
Sedimentological analysis of core and microscopic analysis of the samples taken, defined the environment of deposition.
Electron microprobe results were the most useable and %SiO2, SO2, TiO2, Al2O3, MgO, CaO, FeO, Na2O, K2O and Cl were compared against varying depositional environments.
The results indicate that with increasing distance from the sediment provenance area aluminium and magnesium increase and iron decreases within the glaucony lattice. No trend in glaucony composition with changing lithofacies can be detected.
The degree to which glaucony composition can be used to define a sequence stratigraphic framework is not well defined by this data set.