Palynofacies and Palynological Analysis of Late Triassic Sediments from the Kentish Knock-1 Well (Northern Carnarvon Basin) : Reconstruction of vegetation history, interpretation of climate and sea level changes and placement in regional zonation
This study has integrated palynofacies and palynological analyses of samples from the Northern Carnarvon Basin (NCB) to ascertain sea level, vegetation and climate variations of the North West Australian shelf during the Late Triassic, as well as correlating the sediments with a major biovent within the regional stratigraphy. The sediments were found to be deposited in an environment grading between floodplain, marginal marine and oxic shelf settings. Using the palynological assemblages, mostly dominated by Falcisporites australis, the section was found to fall in the Middle M. Crenulatus spore-pollen zone of Norian age, deposited in the Mungaroo Formation in the Northern Carnarvon Basin. The palynological data were assigned to botanical affinities and manipulated to be used in a Sporomorph Eco Group (SEG) study. This enabled the reconstruction of vegetation history, the interpretation of sea level based on available niche areas for different ecological groups, and the interpretation of climate based on changes in flora within an ecological group. Climate oscillated, but overall showed a shift towards warmer and drier conditions. Sea level was determined by both palynofacies and SEG results, and found to slowly fall for most of the section, except for at the event associated with the oxic shelf conditions and the major bioevent: H. balmei Microplankton zone.