德令哈盆地尕海湖DG03孔岩芯矿物组合与古环境变化
- 收稿日期:
1900-01-01
- 修回日期:
1900-01-01
- 刊出日期:
2007-10-10
摘要: 对气候敏感区德令哈盆地尕海湖DG03孔岩芯的矿物学分析表明,DG03孔岩芯的矿物主要包括石英、斜长石、微斜长石、绿泥石、伊利石、方解石、文石、白云石、石膏及石盐等。岩芯记录了尕海湖约11 ka以来(AMS14C年龄)的古环境变化。根据矿物、碳酸盐含量及岩性的变化,整个岩芯可划分为三个部分:Ⅰ. 约11 ka~10 ka BP,晚冰期末期;Ⅱ. 10 ka~4 ka BP,全新世早中期;Ⅲ.4 ka至今,全新世晚期。矿物组合表明,自晚冰期以来,尕海湖先后经历了湖泊演化的逆向和正向演化阶段,即尕海湖先后经历了晚冰期的干冷气候,早全新世的暖干气候,中全新世的暖湿气候以及晚全新世以来的逐渐干冷的气候。岩性分析还表明,尕海湖沉积环境复杂,存在多种微相沉积。
Mineral Assemblages and Palaeoenvironmental Changes of Core DG03 of Gahai Lake in Delingha Basin
- Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008
- Received Date:
1900-01-01
- Rev Recd Date:
1900-01-01
- Publish Date:
2007-10-10
Abstract: Gahai Lake lies in the conjunction area of some largescale climatic systems such as East Asian monsoon area, southwest monsoon area and westerly wind and so on. Through studies on some palaeoenvironmental proxies such as minerals, grain size and carbonate content in Core DG03, we have analyzed and discussed the characteristics of palaeoenvironment changes in Gahai Lake, where is a sensitive area for climatic change. The research results show that the main minerals in core DG03 include quartz, plagioclase, microcline, chlorite, illite, calcite, aragonite, dolomite, gypsum and halite. The core records the palaeoenvironmental change information of Gahai Lake since about 11ka BP (AMS14C age). According to change characteristics of minerals and lithology, the core is divided into three parts: Ⅰabout 11 ka~10 ka BP, the last period of lateglacial (Younger Dryas event); Ⅱ 10 ka~4 ka BP, the early and middle Holocene; Ⅲ 4 ka ~0 BP, the late Holocene. The mineral assemblages in different period indicate that the water level of Gahai Lake experiences a process of lowhighlow and accordingly salinity highlowhigh. Gahai Lake orderly experiences the reverse and forward process of lake evolution. Combining the lithology and grain size, we speculate that Gahai Lake area orderly experienced the cold and dry climate of lateglacial, the warm and dry climate of early Holocene, the warm and wet climate of middle Holocene and the gradually cold and dry climate of late Holocene. The analysis of lithology also shows that there is a complex sedimentary environment and there are some different types of terrestrial deposits in Gahai Lake and the influence of alluvialproluvial deposition is through the whole Holocene. But we believe that the complex sedimentary environments can better reveal the change characteristics of regional environment.
张西营. 德令哈盆地尕海湖DG03孔岩芯矿物组合与古环境变化[J]. 沉积学报, 2007, 25(5): 767-773.
引用本文: |
张西营. 德令哈盆地尕海湖DG03孔岩芯矿物组合与古环境变化[J]. 沉积学报, 2007, 25(5): 767-773.
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ZHANG Xiying. Mineral Assemblages and Palaeoenvironmental Changes of Core DG03 of Gahai Lake in Delingha Basin[J]. Acta Sedimentologica Sinica, 2007, 25(5): 767-773.
Citation: |
ZHANG Xiying. Mineral Assemblages and Palaeoenvironmental Changes of Core DG03 of Gahai Lake in Delingha Basin[J]. Acta Sedimentologica Sinica, 2007, 25(5): 767-773.
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