...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Quaternary geochronology >OSL chronology for lacustrine sediments recording high stands of Gahai Lake in Qaidam Basin, northeastern Qinghai-Tibetan Plateau
【24h】

OSL chronology for lacustrine sediments recording high stands of Gahai Lake in Qaidam Basin, northeastern Qinghai-Tibetan Plateau

机译：青藏高原东北部柴达木盆地盖海湖高位湖相沉积物的OSL年表

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Qaidam Basin in the northeastern Qinghai-Tibetan Plateau (QTP) is one of the largest hyper-arid intermontane basins in the northern hemisphere, and has abundant records for the study on palaeo-lake level fluctuations and palaeoclimatic changes. Significant efforts have been invested to define the timing of shoreline deposits using radiocarbon dating. However, due to the dating limit, the absence of organic materials and carbon reservoir effects for radiocarbon dating in arid areas, it is difficult to establish a reliable chronology for shoreline deposits. Therefore, controversy exists regarding the chronology for the high lake level in the Qaidam Basin, as well in the QTP. Some proposed that high lake levels occurred during late Marine Isotope Stage (MIS) 3, while others recently argued that the highest lake level in the QTP and adjacent regions existed in MIS 5. In Gahai Lake (now a salt lake), we investigated a section comprising lacustrine and shoreline deposits, which was about 25 m above the present lake level. Seven samples were collected for quartz optically stimulated luminescence (OSL) dating. A sample collected from a fine sand layer (the bottom of the section, and 12 m above the present lake level), which was assumed to have been deposited underwater, gave an OSL age of 82 +/- 8 ka. It suggested that the lake level was at least 12 m higher than present in late MIS 5. The high lake level could maintain till about 73 +/- 6 ka, and then decreased. This lake level decrease resulted in a gravel layer deposit between 73 +/- 6 and 63 +/- 6 ka (roughly during MIS 4). The lake level rose again (about 24 m above the present lake level) between 63 +/- 6 and 55 +/- 5 ka (roughly in early MIS 3). No lacustrine or shoreline deposits higher than the top of the current section were found around Gahai Lake. Thus, higher than present lake levels in Gahai Lake occurred in both late MIS 5 and early MIS 3.
机译：青藏高原东北部的柴达木盆地是北半球最大的高干旱山地间盆地之一，在研究古湖水位波动和古气候变化方面有着丰富的记录。已投入大量精力来确定使用放射性碳测年的海岸线沉积时间。然而，由于日期限制，干旱地区放射性碳定年的缺乏有机材料和碳储集作用，很难为海岸线沉积物建立可靠的年表。因此，在柴达木盆地以及QTP的高湖水位的年代问题上存在争议。一些人提出在海洋同位素阶段3（MIS）后期发生高湖位，而另一些人则提出在MIS 5中存在QTP及其附近地区的最高湖位。在嘎海湖（现为盐湖）中，我们调查了一个包含湖相沉积物和海岸线沉积物的断面，其高度比目前的湖面高约25 m。收集了七个样品用于石英光激发发光（OSL）测年。从细砂层（该区域的底部，并高于当前湖面高度12 m）收集的样品（假定已沉积在水下）的OSL年龄为82 +/- 8 ka。这表明湖泊水位比MIS 5后期的水位至少高出12 m。湖泊高水位可以维持到大约73 +/- 6 ka，然后下降。湖泊水位下降导致砾石层沉积在73 +/- 6和63 +/- 6 ka之间（大约在MIS 4中）。湖泊水位在63 +/- 6和55 +/- 5 ka之间（大约在MIS 3早期）再次上升（比目前的湖面高约24 m）。在嘎海湖附近未发现高于当前断面顶部的湖泊或海岸线沉积物。因此，MIS 5后期和MIS 3初期都发生了高于目前Gahai Lake湖水位的情况。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号