西藏色林错12ka以来的湖泊退缩过程——基于古湖岸线的OSL测年

青藏高原内陆封闭湖泊的水体演化是古气候变化的良好地质载体,其中湖泊古湖岸线变迁蕴含了丰富的地质信息,对其识别和研究是认识导致湖泊退缩的气候或构造变化的关键。色林错是青藏高原第二大内陆湖泊,保存了一系列古湖岸线。我们对色林错东北岸保存完好的古湖岸线进行了研究。对这些古湖岸线样品中的石英颗粒使用单片再生法(Singlealiquot regeneration)进行OSL测年,测定年龄分别为12.2±0.8 ka、6.3±0.4 ka和2.3±0.2 ka。表明色林错在约12.2 ka、6.3 ka和2.3 ka±至少出现了3次阶段性湖泊收缩过程。

The shrinking process of Siling Co in the past 12 ka:Based on OSL dating of past shorelines

The evolution of inland lakes in Tibet Plateau provides important information about past climatic change. The retreating processes of lake shorelines can be used to infer lake evolutions forced either by tectonic events or climatic change. Identification of the past shorelines is very important in the recognition of climate and tectonic events. In this paper,we focused on studying the lake of Siling Co,which is the second largest inland lake in Tibet Plateau. Our field investigations indicate that well-preserved shorelines can be found in the northeastern bank of this lake. By using single-aliquot regenerative-dose(SAR)protocol method,we yielded three ages for the past shorelines,which imply that stepwise retreating of the lake occurring at 12.2 ka, 6.3 ka and 2.3 ka,respectively.