王宁, 刘卫国, 常宏, 安芷生. 中更新世以来新疆罗布泊地区气候演化过程[J]. 海洋地质与第四纪地质, 2009, 29(2): 131-137. DOI: 10.3724/SP.J.1140.2009.02131
引用本文: 王宁, 刘卫国, 常宏, 安芷生. 中更新世以来新疆罗布泊地区气候演化过程[J]. 海洋地质与第四纪地质, 2009, 29(2): 131-137. DOI: 10.3724/SP.J.1140.2009.02131
WANG Ning, LIU Weiguo, CHANG Hong, AN Zhisheng. EVOLUTIONARY PROCESS OF THE CLIMATE OF LOP NUR REGION OF XINJIANG SINCE MID-PLEISTOCENE[J]. Marine Geology & Quaternary Geology, 2009, 29(2): 131-137. DOI: 10.3724/SP.J.1140.2009.02131
Citation: WANG Ning, LIU Weiguo, CHANG Hong, AN Zhisheng. EVOLUTIONARY PROCESS OF THE CLIMATE OF LOP NUR REGION OF XINJIANG SINCE MID-PLEISTOCENE[J]. Marine Geology & Quaternary Geology, 2009, 29(2): 131-137. DOI: 10.3724/SP.J.1140.2009.02131

中更新世以来新疆罗布泊地区气候演化过程

EVOLUTIONARY PROCESS OF THE CLIMATE OF LOP NUR REGION OF XINJIANG SINCE MID-PLEISTOCENE

  • 摘要: 综合罗布泊LS2孔的碳酸盐含量、总有机碳、总氮和碳氮比的多指标分析,重建了该地区中更新世以来的沉积环境和气候环境的演化过程。结果表明,中更新世以来罗布泊地区沉积环境经历了中更新世的浅湖相沉积(厚度为12 m)-滨湖相沉积(厚度约为46 m)-浅湖相沉积(厚度为11 m)-滨湖相沉积(厚度为28 m)-晚更新世至今的滨湖相向风成相沉积(厚度约为18 m)环境的演变过程;气候演化过程可以分为7个阶段:阶段Ⅰ(深度115~103 m)气候由暖干向冷干气候转变;阶段Ⅱ(深度103~82 m)冷湿和暖干交替变化;阶段Ⅲ(深度82~67 m)气候相对暖干;阶段Ⅳ(深度67~57 m)气候冷湿;阶段Ⅴ(深度57~46 m.)气候温暖且偏干;阶段Ⅵ(深度46~18 m)气候主要在冷湿背景下夹有3次暖干的气候波动;阶段Ⅶ(深度18~0 m)气候干旱化加剧。该研究表明,中更新世时期罗布泊地区沉积环境以浅湖相-滨湖相为主,并在晚更新世发展为以风成相堆积为主;气候变化的水热组合形式主要遵循着"冷湿-暖干"的变化模式。

     

    Abstract: Climate variability since the mid-Pleistocene is studied from the proxies in core LS2 drilled in the Lop Nur region (N39°46'39.3″, E88°23'18.2 ″) in the eastern Tarim basin, Xinjiang, China. Geochemical properties, including CaCO3 content, total organic carbon content (TOC) and total nitrogen content (TN), have been determined to reconstruct the environmental evolution of the area since the mid-Pleistocene. Change of sedimentary facies of Lop Nur region since the mid-Pleistocene is documented through the lithology of sediments. From bottom to top, the sedimentary facies of LS2 core can be classified into shallow lacustrine, shore-lacustrine, shallow lacustrine, shore-lacustrine and shore-lacustrine to aeolian deposites, with thickness of 12 m, 46 m, 11 m, 28 m and 18 m respectively. Evolutionary process of the climate can be divided into seven stages:Ⅰ(depth of 115~103 m), changing from warm-dry to cold-dry; Ⅱ (depth of 103~82 m), alternating between cold-wet and warm-dry; Ⅲ (depth of 82~67 m), relatively warm and dry; Ⅳ (depth of 67~57 m), relatively cold-wet; Ⅴ (depth of 57~46 m), relatively warm and dry; Ⅵ (depth of 46~18 m), three warm-dry climate fluctuations folded in the cold-wet climate background; Ⅶ (depth of 18~0 m), intensified arid. This study shows that the sedimentary environment is dominated by shallow lacustrine to shore-lacustrine facies during mid-Pleistocene, while mainly aeolian deposits since the late Pleistocene. The hydrothermal characteristics of climate mainly have been following the form of "cold wet-warm dry" in the region since mid-Pleistocene.

     

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