Project

 
 
ABOUT

About

The aim of HYRAX is to develop a novel and extremely promising palaeoenvironmental archive from southern Africa: the rock hyrax (Procavia capensis) midden. These stratified accumulations of urine and faecal pellets contain reliable, high resolution records of long-term climate and vegetation change in southern Africa spanning the last 50,000 years. As a new palaeoenvironmental archive, rock hyrax middens offer the first opportunity to obtain reliable high-resolution stable isotope and pollen records that can provide detailed information regarding past climate and vegetation change in the region.
When coupled with high-precision chronologies, these proxies provide sub-annual to multi-decadal records of rapid environmental change spanning thousands of years. In comparison with other terrestrial palaeoenvironmental archives from the region, which can generally only be resolved to millennial to multi-millennial timescales, hyrax middens provide an improvement in resolution of three to four orders of magnitude (Fig. 1).

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Fig 1: Comparison of a recent syntheses of Holocene palaeoenvironmental records from southern Africa ((a) Thomas and Shaw, 2002; (b) Thomas & Burrough, 2012) with the high resolution stable nitrogen isotope record from rock hyrax middens from Spitzkoppe, Namibia (c) (Chase et al., 2009). Whereas scenarios based on the data compiled in diagram ‘a’ and 'b' were conflicting, and ultimately inconclusive, the data obtained from the hyrax middens exhibits strong correlations with a wide range of other records, and has allowed for a substantial and fundamental revision of conceptual models regarding subtropical southern hemisphere climate change during the Holocene (Chase et al., 2009).
This improvement in reliability and resolution makes hyrax middens ideal for acquiring records of long-term climate and vegetation change that:

1) can be directly calibrated and compared to instrumental records to obtain quantitative estimates of palaeoclimatic parameters, and

2) can be found across much of southern Africa, allowing for detailed synoptic palaeoclimatic reconstructions at scales that allow for detailed comparisons with general circulation model (GCM) simulations.

References

Chase, B. M., Meadows, M. E., Scott, L., Thomas, D. S. G., Marais, E., Sealy, J., and Reimer, P. J. (2009). A record of rapid Holocene climate change preserved in hyrax middens from southwestern Africa. Geology 37, 703-706.

Thomas, D.S.G., Burrough, S.L., 2012. Interpreting geoproxies of late Quaternary climate change in African drylands: implications for understanding environmental change and early human behaviour. Quaternary International 253, 5-17.

Thomas, D. S. G., and Shaw, P. A. (2002). Late Quaternary environmental change in central southern Africa: new data, synthesis, issues and prospects. Quaternary Science Reviews 21, 783-797.

 
 
 
 
 
 
 
 
 
 
 
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