Palaeoenvironmental evidence for synchronous changes in calcite flowstones formation, speleothems erosion and/or (re)dissolution and equatorial wetter conditions in the tropical karst of Mount Hoyo (N.E. Zaire [actually Democratic Republic of Congo])
1998
Michel, R. (Ministere de la Region Wallonne. Direction generale de l'amenagement du territoire, du logement et du patrimoine, Namur (Belgium))
Speleothems and detrital sediments from Mount Hoyo (1.5 N, 30 E) caves reveal clay mineral assemblages and relative pollen composition indicating important changes in tropical karst palaeoenvironments in the past 150,000 year B.P. (before the present). This multidisciplinary study shows a correlation between : three calcite flowstone levels and equatorial mountainous or rain forest conditions; aragonite speleothem formation and open herbaceous wooded savanna; gravel deposits covered by sulfate gypsum and dry-cold grassland and/or afromountainous taxa. Present climatic and edaphic conditions of the pollen taxons observed in these deposits suggest palaeotemperatures oscillating between or or = -4 degrees C during the hypothermal of Pleistocene period from modern (23 degrees C) external value. These geomorphological phenomena are thus very interesting climatic indicators for understanding the karst dynamics and tropical palaeoenvironments.
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