News Archive

Field trip to the atoll of Aldabra, Seychelles (Jan 2018)

Several researchers from the DFG Forschergruppe 1644 (CHARON) have returned recently from their sampling trip to the Aldabra atoll which is the world's second-largest coral atoll. It is situated in the Aldabra Group of islands in the Indian Ocean that are part of the Outer Islands of the Seychelles.

The researchers from the Georg-August university Göttingen are interested in the microbial alteration of geochemical and isotope proxies in fine-grained carbonate sediments. groupA combined approach of pore water analyses, mineralogical and isotope analyses, plus NGS-based metagenomic and metatranscriptomic analyses of sediment microbial communities is developed to trace changes in fine-grained primary carbonates at shallow sediment depth in a tropical lagoonal setting on the atoll of Aldabra. The sediments will be screened for corrosion and recrystallization of existing carbonate crystallites as well as syntaxial growth or even new precipitation, supplemented with δ13C and δ18O analyses. These traditional stable isotope measurements are complemented by δ26Mg and δ44Ca analyses to assess their susceptibility with respect to pore water changes and microbial activity. The study provides an important basis to assess traditional stable isotope signals in the fossil record, which are widely used as palaeoenvironmental proxies, as well as a test for the use of non-traditional isotopes for tracing diagenetic pathways in a natural setting.

More information:

-> CHARON Homepage
-> press release (german only)