Wstępne badania izotopowe zmienności warunków klimatyczno-limnologicznych w okresie sedymentacji wistuliańskichosadów jeziornych z Jaroszowa
Abstract
PRELIMINARY ISOTOPE STUDIES OF EVOLUTION OF CLIMATIC-LIMNOLOGICCONDITIONS DURING DEPOSITION OF THE VISTULIAN LAKEDEPOSITS IN JAROSZÓW (SW POLAND)
Summary
Calcite concentration, and carbon and oxygen isotope analysis have been carried out in ten samples of sediments
from Vistulian lake 3 m thick sequence from Jaroszow (SW Poland). Two covariance trends, the positive and the negative for the lower and upper part of the sequence, respectively, suggest dramatic change of sedimentary conditions after sedimentation of the first meter of the sequence. Despite subsequent hydrological closing of the lake, the over -7%0 shift of the 81 0 value proves significant cooling of the climate and corresponding increase in Eh value in the sediments. The sediments of the layer ca 2.1 m over the floor of the sequence represent the Vistulian climatic pesimum that were dated due C-14 method on 19.250 yr. BP. The third event of the evolution of the lake corresponds to substantial increase in temperature, slight eutrophication, extensive evaporation and the final extinction of the lake. The gyttjawith several percent of gypsum represents the final stage of the lake sedimentation.
Summary
Calcite concentration, and carbon and oxygen isotope analysis have been carried out in ten samples of sediments
from Vistulian lake 3 m thick sequence from Jaroszow (SW Poland). Two covariance trends, the positive and the negative for the lower and upper part of the sequence, respectively, suggest dramatic change of sedimentary conditions after sedimentation of the first meter of the sequence. Despite subsequent hydrological closing of the lake, the over -7%0 shift of the 81 0 value proves significant cooling of the climate and corresponding increase in Eh value in the sediments. The sediments of the layer ca 2.1 m over the floor of the sequence represent the Vistulian climatic pesimum that were dated due C-14 method on 19.250 yr. BP. The third event of the evolution of the lake corresponds to substantial increase in temperature, slight eutrophication, extensive evaporation and the final extinction of the lake. The gyttjawith several percent of gypsum represents the final stage of the lake sedimentation.