Age determination of eastern Weddel Sea sediments

The huge ice shelves in West Antarctica -the Ross and Filchner/Ronne Ice Shelves- habe probably extended out on th continental shelf during the late Wisconsin (Stuiver et al., 1981). Previous discussions, which have focused on the Ross Sea, have suggested (1) that the ice extended across the whole continental shelf (Denton et al., 1975; Kellog et al., 1979, doi:10.1130/0091-7613(1979)7<249:LQEOTW>2.0.CO;2) or (2) that there was only a minor ecpansion (Drewry, 1979). Here we present sedimentological data from the Weddel Sea which suggests that a late Wisconsin grounded ice sheet extended to the shelfe edge. The evidence includes a recent thicker ice in Ellsworth Mountains at the head of the Filchner/Ronne Ice Shelf (Rutford et al., 1980). This thickening would lead to an expansion of the inland ice sheet over the continental shelf, filling up the Weddell Sea embayment.西南极洲的巨型冰架——罗斯冰架（Ross Ice Shelf）与菲尔希纳-龙尼冰架（Filchner/Ronne Ice Shelf）——在晚威斯康星冰期大概率曾向大陆架延伸（Stuiver等，1981）。此前针对罗斯海的相关研讨曾提出两类假说：其一，冰盖曾覆盖整个大陆架（Denton等，1975；Kellog等，1979，doi:10.1130/0091-7613(1979)7<249:LQEOTW>2.0.CO;2）；其二，冰盖仅发生了小幅扩张（Drewry，1979）。本研究基于威德尔海（Weddell Sea）的沉积学数据，提出晚威斯康星冰期时陆基冰盖曾延伸至大陆架边缘。相关证据包括菲尔希纳-龙尼冰架源头的埃尔斯沃思山脉（Ellsworth Mountains）近年观测到冰层增厚现象（Rutford等，1980）。该冰层增厚事件将推动内陆冰盖向大陆架扩张，进而填满威德尔海海盆（Weddell Sea embayment）。