新疆罗布泊地区第四纪环境演变  

QUATERNARY ENVIRONMENTAL EVOLUTION OFTHE LOP NUR REGION, CHINA

作　　者：闫顺[1] 穆桂金[1] 许英勤[1] 赵振宏 

机构地区：[1]中国科学院新疆地理研究所 [2]新疆地矿局第二水文地质队

出　　处：《地理学报》1998年第4期332-340,共9页Acta Geographica Sinica

基　　金：国家自然科学基金

摘　　要：新疆罗布泊干涸湖盆中的Ｋ１钻孔揭示了该区第四纪沉积地层。孢粉分析表明，早更新世，当地发育森林－草原植被，中更新世以来，荒漠草原与荒漠交替出现，湖泊的发育可上溯至早更新世。The Lop Nur depression is at the east margin of the Tarim Basin. It is the lowermost place and the conflux center of the basin, covers about 50 000 km 2. The lowermost place is 780 m above sea level. The bio species in the region are limited and their quantity is rare. Especially the species are rapidly reduced after the lake dried up due to human activities in 1970's. The data from the field survey of 1980 and 1981 show 13 families, 26 geniuses and 36 species. The boring site of K 1 locates at the middle of the dried up Lop lake, at 90°15′E and 40°17′N. Depth of the well is 100.2 m. The core is totally divided into 92 layers according to natural sedimentation, and classified into 26 depositional cycles in terms of rhythmic sedimentation from coarse to fine. In general, Holocene series is about 2.70 m thick, including the layers from No.1 to 7. The surface is salt crust, and then mainly clay underneath, upper Pleistocene series is about 14.65 m thick, including the layers from No.8 to 17, and mainly composed of earthy yellow and earthy gray clay; mid Pleistocene series is about 48.86 m thick, including the layers from No.18 to 72. Its Lower part is mainly composed of earthy gray, dark gray and grayish green mudstone with thin beds of gypsum, and upper part is mainly the exchange of dark gray muddy rocky gypsum, mudstone with gypsum. At the top there is a buried weathering crust. The mid Plesistocene series is unconformable with an angle about 15° on the lower Pleistocene. The lower Pleistocene series is about 34 m of visible thickness, including the layers from No.73 to 92, and mainly composed of dark gray mudstone and earthy yellow mudstone. Many muddy gypsum beds and gypsum mudstone beds are interbedded in the middle part. The strata decline with an angle change from 15° to 5° top down. In Paleogene the bio group was carring very important characteristics of the tethys region, and the climate of the basin was moistly warm, and produced large coruferous forest and broad leaf forest with some bushes

关 键 词：罗布泊地区 第四纪 孢粉 环境演变 新疆 

分 类 号：Q913.663[天文地球—古生物学与地层学] P534.63[生物学—古生物学]