Inorganic Gas Isotope Geochemistry

Research group Dr. Hubert Vonhof

Biogenic and a-biogenic carbonates are a common constituent of the sedimentary record. The stable isotope geochemistry of such carbonates holds valuable information of past environmental conditions. We develop isotope techniques to use for paleo-environmental and paleo-climatic reconstructions, both in the marine and terrestrial realm.

Typical archives that we work on include

• marine microplankton (foraminifera)·     
• corals
• stalagmites
• tooth enamel

The isotope composition of marine microfossils and bivalve shells yields information on past temperature variation, and on changes in the carbon- and water cycle.

Isotope analysis on tooth enamel and stalagmites gives insight in the terrestrial carbon cycle and animal diet, as well as on changing rainfall patterns through time. These techniques are applied with the aim to unravel past hydroclimate variability, often in relation to biodiversity changes.

Another specific focus for this group is of technical nature, and lies in the development of stable isotope techniques on very small sample amounts, and in the combination of different isotope techniques. Some technical key projects are:

• the further development of the isotope analysis of microscopic amounts of fluid inclusion water in stalagmites.
• the analysis of single specimen planktonic foraminifera.