Dr Brian Chase
My present research focuses on the development and evaluation of new palaeoenvironmental proxy data sources in the arid to sub-humid environments of southwestern Africa. While this region is highly sensitive to cycles of regional and global environmental change, and has the potential to be a valuable indicator of past climatic variability, only a very few palaeoenvironmental archives have been recovered from the area, and its environmental history remains poorly understood. As a result, models that have been developed to elucidate the dynamics of regional ecosystems, and the environmental context for human and cultural evolution are often contentious, lacking sufficient evidence to make robust interpretations.
This paucity of palaeoenvironmental information is largely a function of: 1) the region's climate that often precludes the preservation of organic proxy data sources, and 2) the limitations of radiocarbon dating. My research concentrates on overcoming these obstacles by identifying and analyzing proxy archives that have either not experienced or are resistant to the effects of the region's pronounced seasonality, and by applying luminescence dating techniques to both palaeogeomorphological and palaeoecological archives to expand both the range of material that can be dated, as well as the length of the functional chronology that can be obtained.
At the moment, I am exploring three primary research themes, two of which are focused on improving our understanding of environmental change in southwestern Africa, and a third that is broader in scope, exploring the Southern Hemisphere as a whole. These themes are:
- The analysis of the aeolian deposits of southwestern Africa and their implications for the past dynamics of atmospheric and oceanic circulation systems in the African sector of the Southern Hemisphere.
- The identification of palaeoecological proxy archives along the west coast of southern Africa, including fossilized herbivore middens and pollen records from coastal wetlands in the Western Cape that predate the Last Glacial Maximum.
- The creation of a database of proxy information from the Southern Hemisphere that will allow for:
- the visualization and identification of the spatial and temporal patterning of palaeoenvironmental trends,
- the evaluation of hypotheses for the forcing mechanisms of environmental change, and
- the development and evaluation of models that can be used to explore the dynamics and relative importance of different forcing mechanisms on Southern Hemisphere climates.