论文部分内容阅读
研究了西藏吉隆—沃马盆地龙骨沟剖面新近纪沉积环境 ,作了古地磁年代学研究 ,认为喜马拉雅山北坡新生代断陷盆地发育始于 7.2MaB .P .,3.2MaB .P .湖盆萎缩消亡 ,标志着喜马拉雅山地区在 7.2MaB .P .和3.2MaB .P .发生过强烈的隆升事件 .沃马盆地龙骨沟剖面所含三趾马动物群化石层年龄大约为 7.0～ 6 .7MaB .P .,隐示着此时青藏地区三趾马生活区与当时的华北平原三趾马生活区有着大体相当的地理、气候环境 .之后由于喜马拉雅山持续抬升 ,断陷盆地下沉 ,并在 5 .9～ 3.6MaB .P .期间湖盆面积最为广阔 .青藏高原抬升而华北平原沉降 ,中国西部地区地形高于东部 ,东西部气候环境发生重大差异 .3.6MaB .P .由于青藏地区持续强烈隆升 ,西部地区河流切穿古老湖盆 ,3.2 0MaB .P .吉隆—沃马湖盆萎缩 ,于 1.7MaB .P .逐渐消失 ,进入侵蚀切割阶段
The sedimentary environment of the Neogene in the Longgugou section of the Geelong-Wolma Basin, Tibet was studied. Based on the paleomagnetic geochronology, the Cenozoic fault basin developed on the northern slope of the Himalayas started from 7.2MaB .P., 3.2MaB.P. The withering and shrinking of the Himalayas indicate that the Himalayas had a strong uplift at 7.2MaB .P. And 3.2MaB.P. The fossil layer of the Trippodomala fauna contained in the Longgougou section of the Wuma Basin is about 7.0-6. 7MaB.P., Implying that the area of the Three-toed Horse in the Qinghai-Tibet region at this time has a roughly equivalent geographical and climatic environment with the then-North China Plain Tri-Toema Living Area, and then the subsidence basin subsided due to the continuous uplift of the Himalayas During the interval of 5.9 ~ 3.6MaB.P., the area of the lake basin was the largest, with the Qinghai-Tibet Plateau uplifted and the North China Plain subsided, and the topography in western China was higher than that in the east with significant differences in the climate of the eastern and western regions.3.6MaB .P. Strong uplift, the western region of the river cut through the ancient lake basin, 3.2 0MaB. P. Geelong - Woma basin shrinkage, at 1.7MaB. P. Gradually disappear into the erosion cutting stage