Resolving The Late Paleozoic Ice Age In Time And Space PDF Download

The following dissertation chapters refine the timing and spatial distribution of ice throughout western Gondwana during Earth’s penultimate icehouse. The glaciation history of the Paraná Basin is now restricted to the latest Carboniferous, and likely occurs in sync with a late Carboniferous deglaciation in the Karoo Basin. Furthermore, two additional deglaciation events in the Karoo Basin are contemporaneous with base-level rise in the Paraná Basin and occur at 296 and 282 Ma. Accompanying the deglaciation events and base-level fluctuations across the latest Carboniferous and early Permian in this region of Gondwana are large shifts in detrital zircon provenance. In the Paraná and Tepuel basins, sub-glacial and ice-proximal deposits are largely enriched in local zircon sources, whereas the terminal phase of glaciation in these basins are associated with far-field sediment sources. In the Paraná Basin, the Damara Orogenic Belt and east African Congo and Tanzania cratons supply far-field sediments. In the Tepuel Basin, far field sediments are likely sourced from the Ellsworth Block of Antarctica. In closing, significant questions about the glaciation history, ice distribution and climate system across the LPIA are raised by this contribution, which require future study. The observed deglacial events in the Paraná and Karoo basins track with the pCO2 record across the Carboniferous and early Permian and suggest a global shift in the climate system may be the primary driver for the aforementioned deglaciation events. The refined high-resolution stratigraphic framework for the Paraná and Karoo basins needs to be tested against other high-fidelity ice proximal records in eastern Africa and Australia in order to discern the regional - global response of elevated pCO2 on the ice record. Furthermore, a source for pCO2 needs to be evaluated. Lastly, better temporal and spatial estimates of ice through time are needed to further resolve the scale of deglaciation events and subsequent base-level response across LPIA. These aforementioned opportunities for future study will enable a more holistic view of the Earth’s system and its response in an icehouse-greenhouse transition.