南极无冰区古海蚀龛沉积──古环境研究的新材料

THE PALAEOGOE SEDIMENTS ON THE ICEFREE AREA OF ANTARCTIC: A NEW MATERIAL OF RESEARCH ON PALAEOENVIRONMENT

首次在西南极菲尔德斯半岛长城站地区发现了保存完好的古海蚀龛沉积物 ,研究表明它是后期冰水湖泊沉积环境下的产物 ,该沉积剖面的形成环境反映了本地区距今 46 0 0年以来地貌演化、冰盖进退与古气候的演化过程。古海蚀龛沉积剖面的发现 ,为目前主要基于湖泊沉积物、海洋沉积物及冰芯等进行的南极无冰区古环境研究领域 ,提供了一种新的研究载体。

It is the first time that the palaeogoe sediments kept in good condition were discovered on the Great Wall area,which is located in the Fildes Peninsula,west Antarctic. According to the research on the surface textures of the quartz grains, the grain size features of the sediments and elemental geochemistry such as the ratios of Sr/Ba and B/Ga,we can conclude that the palaeogoe sediments deposit under glaciofluvial lacustrin sedimental environment, and the sedimental environment records the history of the gemorphy evolution ,ice sheet advance and recession and palaeoclimate variability of this area dated from 4600 aBP. The discovery of the palaeogoe sediments is very significant for the palaeoenvironment study on the ice-free area of the Antarctic, because the sediment sections offer a new carrier recording the palaeoenvironment information,except for lake sediments,ocean sediments ,ice core and loess.