关键词: 古海蚀龛沉积;古环境;粒度特征;化学风化

Abstract:

A great deal of palaeogoes have been found in the area around the Great Wall Station located on Fildes Peninsula in west Antarctica, in which intact sedimental sections are preserved. By the analysis of the grain size characteristics and elemental composition in sediments collected from one of those sections, we can affirm that the sedimental section is composed of lake sediments , by which the evolutional history of paleoenviroment in this area since 4600aBP has been reconstructed. The results indicate that chemical weathering of rocks on the earth surface in the Gread Wall Station area is relatively strong from 4000 to 3000aBP, which is suggestive of a comparatively warm period, and this warm period is also imprinted in some sedimental records such as lake and marine sediments. It is proved that palaeogoe sediments can be regarded as a new geological carrier by which we can research palaeoenvironmental evolution history in the ice-free and periglacial area, Antarctica.