Organic proxies for paleoclimate reconstructions
A further field of research of the Young Investigators Group is the application of organic geochemical proxies for reconstruction of past environmental conditions. We are involved in several projects, most of which are collaborative with colleagues at AWI, at the MARUM research center and from international partner institutions.
Organic geochemical proxies we apply include
- alkenone paleothermometry
- compound-specific stable isotope measurements of biomarkers
- novel indices based on relative abundances of several glycerol dialkyl glycerol tetraether (GDGT) lipids derived from microbial membranes like
- TEX86 as paleotemperature proxy
- BIT index for the reconstruction of terrigenous input
- MBT/CBT index to estimate past mean air temperatures and soil pH
Novel proxy indices based on membrane lipids of archaea and bacteria
Deglacial rise in mean air temperature in subtropical Eastern South America reconstructed using GDGT-based climate proxies.
Using our HPLC-MS system, we test and apply the recently developed proxy indices TEX86, BIT, and CBT/MBT to sediments from various settings and covering different time-scales. Projects include Arctic core-top sediment transects, deglacial to Holocene continental margin sediments (e.g., from subtropical South America), and Late Miocene sediment studies.
Alkenone paleothermometry
We apply the well-established alkenone method for reconstruction of sea-surface temperatures (SST) within several collaborative projects. Study areas include the continental margins of Southern Chile, Northwest Africa, and the East Sea (Sea of Japan).