SPELEOARCH

Speleothems and other cave sediments from Siberia: an archive from the boreal climate zone with the potential for climate reconstruction on an annual to decadal basis

We assessed moisture fluctuations caused by the west wind drift from the clastic cave deposits and dripstones from Central Siberian caves (near Lake Baikal and upper Lena River).

The study was based on balanced sedimentological, geochemical and rock magnetic investigations of cave sediments which report moisture changes and document sporadic drastic flooding and even permafrost events in Siberian Caves.

The main objectives of SPELEOARCH (i) cave mapping and investigate cave sediments to document the temporal and spatial variation in deposition of detrital cave sediments and speleothems and to sites relevant for the proposed study (Fig. 1); (ii) monitoring daily cave climate (temperature and humidity) with sensors and monitoring seasonally chemistry of seepage water, to reconstruct present day water properties, as well as temperature and humidity conditions in caves (Fig. 2), (iii) to reconstruct the temperature and precipitation patterns from stable isotopes, growth rates, trace element distribution could be achieved

Yet, we failed to develope a sound age model for the detrital cave infillings and on selected speleothems (using ¹⁴C-AMS and ²³⁴U/²³⁰ Th) failed because cave sediments are by far older than expected as they are beyond the dating window of ²³⁴U/²³⁰ Th method. Recently we recieved for a speleothem sample a preliminary age indicating a few million years using U/Pb system for dating (Jon Woodhead, personal communication 2007; according to the method described in : Woodhead, J., et al. 2006. U–Pb geochronology of speleothems by MC-ICPMS. Quaternary Geochronology 1 (2006) 208–221), indicating that the cave sediments document climatic variability of warmer and moist intervals mostly of late Tertiary and Quaternary or even older.

Partner: J. Kadlec Prag, S. Osinziev Irkutsk, D. Nourgaliev Kazan, S. Bortnikova Novosibirsk, A. Kazansky Novosibirsk, F. Heller Zurich, H. Hercman Warsawa