青藏高原上新世构造岩相古地理  

Pliocene tectonics and lithofacies paleogeography of the Tibetan Plateau

作　　者：季军良[1,2] 江尚松[2] 张克信[1,2,3] 陈奋宁[4] 王国灿[2,5] 杨永锋[1,2,6] 骆满生[1] 

机构地区：[1]中国地质大学(武汉)生物地质与环境地质国家重点实验室,湖北武汉430074 [2]中国地质大学(武汉)地球科学学院,湖北武汉430074 [3]中国地质大学(武汉)地质调查研究院,湖北武汉430074 [4]西安地质矿产研究所,陕西西安710054 [5]中国地质大学地质过程与矿产资源国家重点实验室,湖北武汉430074 [6]陕西省地矿局区域地质矿产研究院,陕西咸阳712000

出　　处：《地质通报》2013年第1期19-30,共12页Geological Bulletin of China

基　　金：中国地质调查局项目<全国重要矿产成矿地质背景研究>(编号:1212010733802);<青藏高原新近纪隆升过程与地质事件群研究>(编号:1212011121261);国家自然科学基金项目<准噶尔盆地南缘安集海河剖面第三系磁性地层学研究及其对天山新生代构造隆升的年代学制约>(批准号:40902049);<重大地质突变期生物与环境协同演化>(批准号:40921062);中央高校基本科研业务费专项资金项目<亚洲内陆渐新世--中新世气候变化的粘土矿物记录>(编号:CUGL09206)

摘　　要：在前人研究成果的基础上,划分出青藏高原及邻区上新世残留盆地共95个,探讨了青藏高原及邻区上新世构造岩相古地理演化。青藏高原上新世总体构造地貌格局主要受控于印度板块与欧亚板块沿雅鲁藏布江缝合带的碰撞及持续挤压,影响着青藏高原广大范围内的构造抬升。东北部昆仑山、祁连山地区是两大构造隆起蚀源区,两大山系夹持的柴达木盆地是高原东北部最大的陆内盆地,祁连山以北和以东地区则以盆山相间的格局接受周围山系的剥蚀物质,直到晚上新世(青藏运动"A"幕)高原东北部进一步强烈隆升,山间盆地抬升成为剥蚀区。新疆塔里木和青藏高原东部羌塘、可可西里地区主体表现为大面积的构造压陷湖盆-冲泛平原沉积区。高原东南部为一系列走滑拉分断裂运动形成的拉分盆地,上新世早期堆积洪冲积相砾岩,中期为湖泊、三角洲沉积,晚期随着山体的进一步抬升,盆地又接受冲洪积扇相砾岩堆积,并被河流侵蚀剥露。高原南部上新世多分布一些近南北向盆地,是响应高原隆升到一定程度垮塌而成的断陷盆地,同东南部拉分盆地类似,上新世沉积相也由早至晚分为3个阶段。恒河地区上新世由于喜马拉雅山的快速抬升,沉积以粗碎屑为主,形成狭长的西瓦利克群堆积。上新世青藏高原总体地势继承了中新世西高东低、南高北低的地貌特征,但地势高差明显较中新世增大。Based on the data obtained from 1：250 000 geological mapping conducted by China Geological Survey in 1996-2008 and available data concerning the Pliocene strata, tire authors recognized 95 remnant basins in the Tibetan Plateau and its adjacent areas. In this study, the Pliocene tectonic evolution and lithofacies paleogeography of Tibetan Plateau has been discussed. The continuous colli- sion between the Indian plate and the Eurasian plate along the Brahmaputra suture zone controlled the overall tectonic geomorphology of the Tibetan Plateau in the Pliocene and extensively affected the tectonic uplift. The Kunlun Mountains and Qilian Mountain to the northeast were two tectonic uplift erosion source areas, which sandwiched the Qaidam basin from the south and the north respectively. The Qaidam basin is the largest interior basin in northeastern Tibetan Plateau. The northern and eastern areas of the Qilian Mountain were characterized by the alternate range-basin pattern, which received denudation materials from surrounding mountains. Further strong uplift in the late Pliocene （called Episode A of the Qinghai--Tibet Movement） changed these intermontane basins into erosional regions. The Tarim basin in Xinjiang arid Qiangtang and Hob Xil in northern Tibet constituted an extensive tectonic sag basin-blunt flood plain deposition region. Southeastern Tibet was composed mainly of pull-apart basins caused by a series of strike-slip faults, which accumulated flood alluvial conglomerates in the early Pliocene and lacustrine arid delta deposits in the middle Pliocene. Flood alluvial conglomerates were deposited again in the late Pliocene due to the further uplift of the mountains. Some nearly NS-trending rift basins were developed in the southern part of the Tibetan Plateau in response to a certain degree of plateau collapse. Sedimentary facies of these basins were divided into three stages from early to late Pliocene, similar to those of southeastern Tibetan Plateau. The Ganges area deposited coarse clastic sediments due

关 键 词：青藏高原 上新世 构造岩相古地理 盆地 

分 类 号：P534.622[天文地球—古生物学与地层学]