Palaeoclimate Reconstruction in the OGU
The organic matter associated with annually deposited sedimentary materials such as lake and ocean sediments, peat bogs, etc. represent invaluable archives of palaeoenvironmental, particularly of palaeoclimate, information. In this area of research the OGU is using a range of analytical techniques to derive chemical indicators of environment and climate change in the recent past (10,000 years) and over geological time to assist in the building of better predictive models of future climate. Such indicators may be found in a variety of settings including: ombiotrophic peat bogs, the sediments of remote upland lakes and the ocean floor. For the peat we are aiming to develop a range of molecular and compound specific stable isotope (δ13C, δ18O, δD) proxies, based on plant or micro-organsim derived components, that can be related to climate. Our work on sediments is focusing on various remote upland lakes in the UK and abroad whilst oceanic sediments are being studied from a number of sites including: the Benguela upwelling region, Tanzania and the Mediterranean Sea. The chosen sites provide opportunities to investigate the responses of the aquatic environment and the lake/marine catchment to changing climate. Measurements that are being made include total organic carbon, bulk and compound specific stable isotope measurements, concentrations of chlorophyll degradation products (chlorins), and lake and catchment derived biomarker compounds, e.g. n-alkyl, isoprenoid lipids, tetraethers etc. Practically all of the palaeoclimate reconstruction studies are parts of much larger research efforts involving collaborations with other established research groups developing complementary multi-proxy climate records.