Funded through DFG grant Ha 1166/17-1. Prof. Bent Hansen in collaboration with Dr. Steffen Kiel []

Developing and testing a method to date fossil methane-seep carbonates using Strontium isotopes

Methane seeps in the deep sea are colonized by an unusual fauna which relies on sulfur- or methane-oxidizing bacteria for nutrition. These faunas are often preserved in the fossil record because the major biogeochemical process at methane seeps, microbial oxidation of methane, results in carbonate precipitation. Such fossils are important for deciphering the evolutionary history of these extraordinary faunas. Unfortunately, it is often difficult to date such carbonates biostratigraphically, for example when they were detached from the originally surrounding sediment or when they are only known from museum collections. This project aims to establish a method to date such carbonates using Strontium isotopes. We will test which of the different carbonate phases within seep carbonates are best suited for Sr-dating. Test cases will be three biostratigraphically well-dated examples of Paleo-, Meso-, and Cenozoic age. When successful, the method will be applied to seep carbonates that are currently poorly dated, but contain fossils that are interesting from evolutionary biologic point of view.