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柴达木盆地北缘苏干湖若干钻孔岩芯发现,水深大于3.0m的沉积物均具有裸眼可分辩的由深色层和浅色层组成的纹层层理.以湖泊中心SG03I孔上部5.5m具有纹层结构的沉积岩芯为研究对象.基于沉积物收集装置的现代过程研究发现,苏干湖夏秋季以浅色的单水方解石为主,冬半年以深色有机质为主,现代湖泊能够形成冬半年深色层和夏半年浅色层的纹层沉积.岩芯中有四种类型的纹层沉积:单水方解石-有机质纹层、白云石-有机质纹层、碎屑-硅藻(碎屑)纹层与文石-有机质纹层,均具有季节特征,属可靠的年纹层,且顶部纹层计年与210Pb测年结果一致.根据纹层计年,年纹层沉积形成于距今2670a以来.苏干湖纹层沉积是中国西部干旱区发现的第一个能够确认为是年纹层的湖泊沉积,4种不同类型的年纹层指示了不同气候类型及其季节差异,具有重建高分辨率气候变化的重要意义.
A number of boreholes in Lake Sugan, the northern margin of the Qaidam Basin, have found that sediments with water depths greater than 3.0 m have laminar bedding composed of dark and light-colored layers that are visible to the naked eye. 5.5m textured sedimentary core is the research object.According to the modern process of sediment collecting device, it is found that the light and light single calcite in the summer and fall of the Lake Sugan, dominated by the dark organic matter in the first half of winter, the modern lake can Forming a dark layer in the winter half-summer and summer half-year light layer deposition layer pattern There are four types of core sediment deposition: single-water calcite - organic textured layer, dolomite - organic textured layer, debris - diatoms Detritus and aragonitic-organic textured layers, all of which have seasonal characteristics, are reliable annual layers, and the top layer ages are consistent with the 210Pb dating results. Since 2670a, the deposition of the Lake Sugan is the first lacustrine sediment to be identified as an annual pattern in the arid region of western China. Four different types of annual patterns indicate different types of climate and their seasonal variations, With the reconstruction of high-resolution climate change of great significance.