The Potential for High Resolution Climate Records From Ice Deposits in Saline Lakes of the Central Andes

在南部的浅盐湖中发现了层状冰沉积物 玻利维亚和北方智利可能提供第一个高分辨率 中国干旱亚热带地区气候变化的记录 安第斯山脉。 冰沉积物高达7米以上的表面， 浅盐湖并延伸至未知深度。 存款 被一层白色的碳酸盐地壳所覆盖 淡水冰和混合有沉积物的冰之间的区别。 所述站点在 位于一个非常干旱的地区（100毫米a.1年平均 年平均气温为3.6度至 9.6oC. 这些沉积物目前正在融化，这表明它们 与现代气候状况不平衡。 冰芯 将从最大的冰层开始， 存款，发现于拉古纳科罗拉多州（22 o 10'S，4289米）， 确定这些沉积物作为高- 解决气候变化。 一条横贯 沉积物将指示层是否水平 连续的 岩芯还将提供同位素的物质， 化学和矿物分析，这需要确定何时 以及这些层是如何形成的。 单脉冲雷达探测将有助于 确定沉积物的厚度以及潜在的 机械钻以获得长记录。 湖泊水位高， 冰川的进展表明， 年期间安第斯山脉亚热带地区的水文收支 晚更新世 这种变化可能是由两个因素造成的： 热带辐合带的南移， 延长了雨季，气温也降低了 Pr 1消除 结果表明，分层冰沉积可能已经开始， 形成于晚更新世时期， 为这一地区的气候变化提供了独特的记录。

Layered ice deposits found in shallow saline lakes in southern Bolivia and northern Chile may provide the first high-resolution record of climatic change from the arid-subtropical region of the Andes. The ice deposits rise as much as 7 m above the surface of shallow saline lakes and extend to unknown depths. The deposits are covered by a white carbonate crust and the layers alternate between freshwater ice and ice mixed with sediment. The sites are located in a very arid region (100 mm a.1 mean annual precipitation) where mean annual temperatures range from 3.6o to 9.6oC. The deposits are presently melting, which indicates they are not in equilibrium with the modern climatic regime. Ice cores will be retrieved from the ice deposits beginning with the largest deposit, which is found in Laguna Colorada (22o10'S,4289m), to determine the potential of these deposits as archives of high- resolution climatic change. A transect of cores across the deposits will indicate whether or not the layers are horizontally continuous. The cores will also provide the material for isotopic, chemical, and mineral analyses, which are needed to determine when and how the layers formed. Mono-pulse radar soundings will help to determine how thick the deposits are and the potential need for a mechanical drill to obtain a long record. High lake levels and glacial advances indicate there was a significant change in the hydrologic budget in the subtropical region of the Andes during the late Pleistocene. This change was probably caused by two factors: a southward shift of the Intertropical Convergence Zone, which lengthened the rainy season, and colder temperatures. Pr1eliminary results indicate that the layered ice deposits may have started to form during this late-Pleistocene interval and therefore could provide a unique record of climatic change for this region.