羌塘盆地查郎拉地区中新生代古气候演化初探 |
修订日期:2001-07-27 |
关键词:palaeoclimate evolution climatic elements climatic sediments climate cycles Mesozoic-Cenozoic Qiangtang basin |
基金项目:原石油天然气集团公司“九五”油气勘探工程重点项目(DQ96YD-04) |
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摘要: |
A Preliminary Study of the Mesozoic-Cenozoic Palaeoclimate Evolution in Chalangla Areas, Qiangtang Basin, Northern Tibet |
This paper has discussed for the first time the distribution features of climatic sediments and the characteristics of climatic majorelements, valence changeable electron elements and minorelements in Chalangla area of Qiangtang basin, northern Tibet, and indicated climatic fossils there. The discussion is based on the field remote sensing survey, the study of a series of climatic sediments in many cross sections and route geological records and petrological and geochemical analysis of majorelements and minorelements. Combined with available information of palaeontology and lithofacies paleogeography, the authors have systematically deduced palaeoclimate characteristics and the Mesozoic Cenozoic transitional evolution in this region, which can be classified into 8 climatic cycles. Late Triassic was warm half humid to humid in the tropics and subtropics, comprising the first climatic cycle. Middle Jurassic showed cyclical variation of semiarid to half humid in the tropics and subtropics, forming the second and third climate cycle. Late Jurassic went through the climatic transition from sweltering half dry to warm half humid and humid to sweltering half dry in the tropics, constituting the fourth and fifth climate cycle. Cretaceous was characterized by warm half moisture in early stage and half aridness to aridness in the tropics and subtropics in late period, which made up the sixth and seventh climate cycle. Tertiary was mainly frigidly dry in the inland subtropics and semiarid to warm and cool in plateau. Quaternary experienced six times of glacial age and five times of interglacial period. Cenozoic totally underwent violent and frequent fluctuation from cold to warm and tended to be increasingly drier and colder. This paper has also analyzed the superposition-coupling relationship of the Mesozoic Cenozoic palaeoclimate evolution to sedimentary cycles and tectonic movement and probed into the main reasons of palaeoclimate variation. |
WEI Yuan-jiang,YANG Xiao-ping,LEI Zhen-yu,ZHANG Hong,LU Wan-yu.2002.A Preliminary Study of the Mesozoic-Cenozoic Palaeoclimate Evolution in Chalangla Areas, Qiangtang Basin, Northern Tibet[J].Acta Geoscientica Sinica,23(1):55-62. |
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