Michael Weber


„Reconstruction of past climate variability during Marine Isotope Stage 3 and the Holocene using speleothems“

In addition to already established climate proxies, such as stable carbon and oxygen isotope and trace elements, also other less common isotope systems can provide valuable information about past environmental conditions. The 87Sr/86Sr-ratio offers additional information as tracer to identify different sources of drip water and possible end-members in the Sr cycle.

During my Master of Science thesis, we developed a technique for in-situ Sr isotope analysis of speleothems by LA-MC-ICP-MS. The first part of the project focusses on the application of this method to different stalagmite samples from different climate zones and ages.

For the second part, a stalagmite from Bunker cave, grown during the Marine Isotope Stage 3, will be investigated. So far, no speleothem record from north of the Alps is known which grew during this period. Our sample will be precisely dated and we will perform high-resolution stable isotope and trace element analyses. We will also determine Sr isotope ratios by our novel LA-MC-ICP-MS method.

The final part of the project is to build a master record based on several Holocene speleothem proxy records. These records will be improved by further dating and additional proxy analyses, including Sr-isotopes, and finally compiled for constructing a speleothem master chronology for the Holocene. These results will then be compared to already existing master records from other archives.

Master thesis:

Developing a method for measuring Sr isotope ratios with LA-MC-ICP-MS on speleothems.