Highly resolved paleoclimate south of the Alps

Cave carbonates, so-called speleothems, represent - compared to lake sediments, deep-sea sediments or tree rings - a relatively new archive of paleoclimatology, which has been the focus of our research group at Leopold-Franzens- Universität Innsbruck during recent years. The goal of this proposal is to successfully complete an investigation of a cave site in the province of Styria, known as Katerloch Cave (Ph.D. student has already started in January 2005). This cave, probably Austria`s most beautiful dripstone cave, was essentially inaccessible for many years. It is interesting to note that most of the up to 6 m tall speleothem formations in this cave are currently inactive. Precipitation of calcite, which gives rise to the vertical extension of stalagmites, is a function of the amount of groundwater dripping into the cave chamber. As the source of this seepage water is meteoric precipitation falling above the cave, dripstones and their internal growth phases can be used as a dipstick for changes in paleo-rainfall. Katerloch Cave offers the opportunity to reconstruct precipitation of past millennia at very high resolution, because its speleothems show a regular internal laminated structure which appears to be of annual origin (based on preliminary absolute age dates). This study will therefore provide new insights into the natural climate variability at the southern fringe of the Alps, which are difficult to achieve using other archives.

Cave carbonates, so-called speleothems, represent - compared to lake sediments, deep-sea sediments or tree rings - a relatively new archive of paleoclimatology, which has been the focus of our research group at Leopold-Franzens- Universität Innsbruck during recent years. The goal of this proposal is to successfully complete an investigation of a cave site in the province of Styria, known as Katerloch Cave (Ph.D. student has already started in January 2005). This cave, probably Austria`s most beautiful dripstone cave, was essentially inaccessible for many years. It is interesting to note that most of the up to 6 m tall speleothem formations in this cave are currently inactive. Precipitation of calcite, which gives rise to the vertical extension of stalagmites, is a function of the amount of groundwater dripping into the cave chamber. As the source of this seepage water is meteoric precipitation falling above the cave, dripstones and their internal growth phases can be used as a dipstick for changes in paleo-rainfall. Katerloch Cave offers the opportunity to reconstruct precipitation of past millennia at very high resolution, because its speleothems show a regular internal laminated structure which appears to be of annual origin (based on preliminary absolute age dates). This study will therefore provide new insights into the natural climate variability at the southern fringe of the Alps, which are difficult to achieve using other archives.