Continental & marine geobiology ecosystems

Lacustrine systems

Lacustrine systems show a broad spectrum with regard to their hydrochemistry and corresponding biological communities.
This spectrum reaches from boiling acid lakes of volcanic craters to calcium-rich freshwater lakes of karst areas and extreme alkaline soda and playa lakes of deserts. These environments form potential model oceans for past times in Earth history, when atmosphere and seawater were principally different from those of today.
The major focus in Göttingen lies on microfacies, geomicrobiology, geochemistry and paleontology of carbonate lake systems. This includes present-day salt and soda lakes (e.g., in Nevada, Indonesia, Kiritimati) as well as their fossil counterparts (e.g., miocene Ries crater lake, mesozoic fresh- to saltwater lakes).
Especially the combined approach of investigating sedimentary structures, trace elements, isotopes (13C, 18O, 87Sr/86Sr) and organisms (e.g. prokaryotes, calcareous algae, ostracodes, palynomorphs) in recent and fossil examples results in new insights concerning the biological feed-back on the Earth system.

Reefs

Reefs in the geobiological sense are communities of CaCO3-forming benthic organisms including corals, sponges, bivalves, algae and/or microbes which form a wave‑ and current-resistant framework. Reefs have lots of different ecological niches hosting an extraordinary biodiversity. Reefs react very sensitively environmental changes (Global Change) and therefore they are excellent environmental indicators. The distribution of reefs in the fossil record exhibits the in the long term controlled fundamental oceanic and atmospheric changes in Earth history.

Cold Seeps

Cold Seeps are small scale subaquatic locations from where e.g. hydrocarbon- and hydrogen sulphur cold fluids seep. Normally it is methane seeping, most of which will be anaerobicly and aerobicly oxidised by various microbes (Archaea and Bacteria) to CO2 and water. Cold Seeps are biodiversity hot spots of extremophile organisms such as chemolithotrophic tube worms (Vestimentifera) and bivalves (e.g. Bathymodiolus, vesicomyide bivalves).
A geobiologically important by-product of the anaerobic oxidation of methane is the formation of certain 13C-depleated carbonates which often have a reef-type character.

contact:

PD Dr. Gernot Arp
Prof. Dr. Joachim Reitner