Quantifying Surface Processes
This project aims to quantify earth surface processes, particularly erosion, over geological timescales in the anomalously elevated regions of Southern Africa and Madagascar, in order to resolve causal links between mantle processes, epeirogeny (a sort of gentle crustal uplift), climate change and ecodynamics. Key to this project is the use of cosmogenic nuclides, particularly of 3He and 21Ne, in order to measure current (103 to 106 yr) surface exposure ages and erosion rates at choice geomorphic localities under a range of surface conditions. By comparing our findings with other, long-term proxies for weathering and erosion, notably exhumation thermochronology, laterite geochronology and offshore sediment studies, we intend to assess current tectonic and geochemical (climate) models for the response of erosion and weathering to Mesozoic flood basalt volcanism and epeirogeny in the independent continental fragments of Southern Africa and Madagascar. Furthermore, we intend to dovetail our study with ongoing molecular biology and drainage studies in these regions, in order to better appreciate the influence of epeirogeny on the evolution of habitats and endemic biodiversity. Our results will also provide a baseline for understanding human-induced surface erosion in order to formulate sustainable land management policies.