PhD: Death of a biome: sedimentary and palaeoecological consequences of the Pennsylvanian collapse of tropical rainforests

The geological record permits the opportunity to identify global perturbations induced by the collapse of the Earth’s tropical rainforests. It has been postulated that mass extinction of vegetation on land could trigger mass extinctions of marine fauna due to huge sediment influxes associated with increased rates of erosion. Observations centred on the Permian-Triassic mass extinction have suggested that this is revealed through global facies signatures, including an increase in braided river alluvium, dilution of nearshore bioturbation and a global stratigraphic gap of coal deposits. However, 50 million years before the Permian-Triassic event, the Earth’s vegetation suffered its first mass extinction event in the form of the Kasimovian Rainforest Collapse (KRC) . The interval succeeding KRC is presently unstudied from a sedimentological and ichnological perspective: detailed original fieldwork analysis of select Euramerican sites will shed new light on the post-rainforest collapse, repercussions and recovery of ecosystems and sediment erosion rates.
The “coal age” tropical rainforests of the Carboniferous are one of the most famous and visually-recognisable chapters of Earth history. Far less well understood are the repercussions of the dramatic collapse and isolation of these Euramerican rainforests at the end of the Carboniferous, associated with the supercontinent assembly of Pangea, concomitant global warming, and the increasing competition from coniferous vegetation. This project will be the first to understand the palaeoecology and sedimentary environments of this post-extinction world, with detailed field-based sedimentological and ichnological analyses of the post-Kasimovian terrestrial ecosystems that dominated Euramerica (potentially utilizing fieldsites in Spain, the USA, Canada and Kazakhstan).