- Portada
- volume 9 (2006)
- number 3-4 - Han-sur-Lesse Symposium - nov. 2004
- COMPLEX STRATIGRAPHIC SEQUENCES IN BELGIAN CAVES: CORRELATION WITH CLIMATIC CHANGES DURING THE MIDDLE, THE UPPER PLEISTOCENE, AND THE HOLOCENE
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COMPLEX STRATIGRAPHIC SEQUENCES IN BELGIAN CAVES: CORRELATION WITH CLIMATIC CHANGES DURING THE MIDDLE, THE UPPER PLEISTOCENE, AND THE HOLOCENE
Abstract
Studies of cave sediments in Belgian caves suggest that continuous sedimentary records through several climatic cycles do not exist. Climate variations induce lithologic variations. In Western Europe, cold periods mainly generate detrital sediments while warm periods are more favourable to speleothems formation. Other factors, as tectonics, can modify type and rate of sedimentation. Uranium-series disequilibrium dating and pollen analysis in karstic sediments allow to construct a chronological evolution of the palaeoenvironments. In this paper, we construct a synthetic climate evolution from caves sedimentary records of the Upper, Middle Pleistocene and Holocene based on the biorhexistasy theory. Cold periods are the frame of mainly physical erosion (freeze, debris flows, etc.). Warm periods represent the biostasy conditions characterized by the development of the forested soils and the predominance of chemical alteration. Thanks to examples coming from the belgian caves, the described phenomena are universal and can be applied to diverse karstic systems, considering the local environments.