期刊文献+
共找到1篇文章
< 1 >
每页显示 20 50 100
Late Pleistocene Climatic Changes in Central Brazil Indicated by Freshwater Sponges
1
作者 Vanessa de Souza Machado Cecilia Volkmer-Ribeiro Roberto Iannuzzi 《International Journal of Geosciences》 2014年第8期799-815,共17页
The Cemitério Palaeolake deposit in Catalao, Goiás State, Brazil, comprises a single, complete lacustrine sequence, dated from less than 27,500 ± 4000 yr B.P. to more than 51,780 ± 400 14C yr B.P. ... The Cemitério Palaeolake deposit in Catalao, Goiás State, Brazil, comprises a single, complete lacustrine sequence, dated from less than 27,500 ± 4000 yr B.P. to more than 51,780 ± 400 14C yr B.P. The unprecedented presence of spongillite and diatomite layers in this deposit was investigated using spicules of continental sponges as proxy data for environmental and climate reconstruction, which was relatively extensive for the ages examined. From the analysis of the sedimentary features and the associations of spicules preserved in the deposit, it was possible to reconstruct the evolution of the limnic system. Five developmental stages were thus identified, corresponding to the installation (lotic and erosion phase), establishment and development of the lake and its colmatation, the latter correlating to the Last Glacial Maximum (LGM). Moreover, based on the ecological requirements of the sponge species identified in the deposit, it was possible to infer the likely weather patterns related to respective phases of the lake. The presence of the sponge species Corvoheteromeyenia australis, presently recorded only from southern South America, indicated that polar incursions originating from the Antarctic were frequent during the last glacial period and might have played a notable role in what is now central Brazil. However, for a short time, drier and hotter weather conditions might have predominated, as suggested by the presence of the species Corvomeyenia thumi. 展开更多
关键词 Spongillites Lacustrine Palaeoenvironment PALAEOCLIMATE Central Brazil Late Pleistocene
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部