Reconstruction of Palaeoenvironment in the Victoria Land and Central Transantarctic Mountains Using a Multiproxy Approach

Abstract

The Ferrar Large Igneous Province is thought to have been emplaced around ~182 Ma. The province includes intrusive, extrusive, and effusive volcanism forming a linear belt for 3500 km, covering parts of Antarctica, Australia, and Tasmania. The intrusive components are the Dufek intrusion and the Ferrar Dolerite sills and dikes; the extrusive components are the Exposure Hill, Mawson, Carapace Sandstone, and Prebble formations, and the effusive component is the Kirkpatrick Basalt. The volcanic sequence is recorded in North and South Victoria Land (NVL and SVL, respectively) and the Central Transantarctic Mountains showing the pre-Ferrar ash units followed by initial stages of violent explosive volcanicity with dolerite dikes and sills. This resulted in the deposition of volcanoclastic units in the region. Afterwards, the nature of volcanism became quieter and covered all three areas (CTM, NVL, and SVL) by the Kirkpatrick Basalt. This project investigates the effect of Ferrar magmatism on the sedimentology, palaeoclimate, palaeoenvironment and palaeobotany of the VL and CTM in Antarctica during the Late Triassic- Early Jurassic. Bulk chemical analysis and petrographic analysis are accomplished to study the influence of the Ferrar volcanism on these areas. All rock samples were affected by the same volcanic events. This is evident from their chemical composition, which fall in the same range and they are dominated by silica. This is also shown in the petrographic analysis, as most samples contain quartz, feldspar, chalcedony, and zeolite. Further information on secondary minerals and their connection to hydrothermal activity after lava solidification are acquired from petrographic analysis. Literature-based paleobotanical collection aids in determining the palaeoclimate and palaeoenvironment in which these fossil plants grew. Graphic illustrations of NVL, SVL, and CTM are constructed using all gathered information and obtained data to visualize the effect of the Ferrar Magmatism on these areas (Pre-, syn-, and post-Ferrar magmatism).

Date of Award	May 2021
Original language	American English