【作者】 金玮；

【导师】 王成善；

【作者基本信息】 成都理工大学 ， 沉积学， 2007， 博士

【摘要】 论文选择青藏高原腹地可可西里盆地、羌塘盆地和措勤盆地晚白垩—古近纪的陆相地层为研究对象，比较详细的开展了青藏高原腹地晚白垩—古近纪的地层学、岩石学、沉积相、物源区分析、磷灰石裂变径迹与油气后期保存的研究。论文的创新及重要研究成果如下：论文根据青海省和西藏地质局的划分方案、孢粉组合和ESR测年数据，结合1：25万区域地质调查和CNPC石油地质调查的最新成果，参考近年来在可可西里盆地和沱沱河盆地进行的古地磁测年数据，将风火山群时代划归始新世—早渐新世，时间为51.0～31.5Ma；根据地层层序、与第三系及下伏侏罗系、白垩系的不整合接触关系结合孢粉组合、ESR年龄值、火山岩定年数据及区域地层资料将羌塘盆地阿布山组、措勤盆地竟柱山组归属于晚白垩世。据沉积岩相特征及其组合，将风火山群沉积相划分为河流沉积体系、扇三角洲沉积体系、湖泊沉积体系和湖泊三角洲沉积体系；将阿布山组的沉积相划分为冲积扇沉积体系、河流相沉积体系、扇三角洲沉积体系和浅湖沉积体系；将竟柱山组的沉积相划分为冲积扇沉积体系、河流相沉积体系、扇三角洲沉积体系和浅湖沉积体系，局部见海侵碳酸盐岩沉积。风火山群物源区为近源的大陆块沉积岩区，古水流方向主要为北东向；双湖托纳木地区阿布山组物源为南部的构造隆起带，古水流方向主要为北东东向；措勤盆地达瓦错地区竟柱山组古水流方向先向南西后向北东流，表明物源方向发生了变化，应该与当时的构造活动和前陆盒地的演化有关。可可西里盆地古近纪沉积岩样品的磷灰石表观年龄均接近地层年龄，平均径迹长度为～12.8μm，表明沉积后未经历过完全退火作用；唐古拉山磷灰石裂变径迹结果表明古近纪开始的快速剥蚀在始新世-渐新世时期转换为低速剥蚀；羌塘盆地裂变径迹年龄数据表明盆地冷却主要集中在两个时间段，一是渐新世，一是白垩纪，这两次冷却事件说明盆地在此时经历了强烈的抬升和剥蚀。在上述研究的的基础上，提出羌塘盆地、措勤盆地主要构造反转开始的时间分别为早白垩世早期和早白垩世末期，结束的时间为晚白垩世早期，表明构造反转的时间早于高原腹地主要生油岩进入生油高峰和生油门限的时间，而高原腹地大型背斜构造主要形成于此构造反转作用下，成为最理想的匹配关系。晚白垩世开始青藏高原腹地处于整体隆升的背景下，有利于油气的保存。更多还原

【Abstract】 This dissertation focuses on the terrestrial strata sequences during thelate Cretaceous- Paleogene period of the Hoh Xil, Qiangtang, and Cuoqin basin in theTibetan Plateau hinterland, where the research degree lags relatively behind, and thedetail studies on stratigraphy, lithology, sedimentary facies, source region analyis,apatite fission track dating and oil-gas reservation process has been carried out. Themain conclusions and progress are as follows:On the basis of former results of geology branch of Qinghai and Tibet province,the pollen proxies and the ESR dating, together with the areal geology investigationon 1:250 thousand scales and the latest geology investigation research of CNPC,consulting the recent geomagnetism dating results in Cenozoic Hoh Xil and TuoTuoriver basin, the epoch of terrestrial Fenghuoshan group belongs to the Eocene- earlyOligocene period and the age is about 51.0～31.5Ma; In according to the study onstrata sequence of Abushan series, the unconformity relation between the Abushanand underlayers, pollen proxies and the ESR dating in Qiangtang basin, the Abushanseries is set to the late Cretaceous stage; As for the Jingzhushan seires in the Cuoqinbasin, it belongs to the late Cretaceous stage.According to further study on the lithology, sedimentary tectonic features andspatial distribution character, Fenghuoshan group is defined as the Fluvial depositionsystem, fan delta deposition system, lacustrine deposition system and the lacustrinefan deposition system, Abushan series belongs to the combined deposition system ofalluvium fan, fluvial sediment, fan delta system and the shallow lake system, andJingzhushan series show large similarity with the Abushan series, which is justcharacteristic of carbonate deposition of ocean transgression process locally.The provenance for the Fenghuoshan group is mainly proximal continentalsedimentary rock regions and the paleocurrents were dominantly to northeastward.The conglomerate of Abushan series hails from the Central Uplifting Zone, theprovenance comes from the southernwest Central Uplifting Zone, which based on theclastic composition of sandstone for the Abushan series of Shuanghu Tuonamu region,and the paleocurrents were dominantly to northeastward. The paleocurrents of Jingzhushan series were begin to southwestward and afterward to northeastward,which shows the direction of palaeocurrent is transformed and related to the tectonicfunction and evolution for foreland basin.Within the Hoh Xil basin, seven out of nine sedimentary samples deposited in thePalaeogene yield apparent fission track ages are～47-～36Ma (Eocene), they areapproached to the stratigraphic timescale, whose mean track lengths are variable butcentred on～12.8μm, which shows the sedimentary samples didn’t experience whollyannealing. The fission track results combined with stratigraphic constraints from theHoh Xil Basin suggest maximum palaeo-temperatures between～100℃and～120℃were experienced in the Oligocene by most of the sediments sampled in this study.Rapid denudation beginning in the Palaeogene followed by a change to slowerdenudation in the Eocene-Oligocene is suggested by the apatite fission track resultsfrom the Tanggula Mountains, and is consistent with reduced erosion in the Hoh Xilregion from the Miocene to Recent implied by the northeast advancing deformationfront model. The cooling of Qiangtang basin is focused on two timescales, they areOligocene and Cretaceous.Based on the above investigation, the dissertation studies the time and thefunction for the inverted structure of hinterland of the Tibet Plateau, which expressesthe time for inverted structure was early to the time for Oil-forming height peak andthe oil source rock, the large anticlines structure of Qiangtang basin are mainlyformed between late Jurassic and early cretaceous, therefore, the essential elementswere spatially well deployed, and temporally, petroleum-forming processes also hadgood relationship. After later cretaceous, the hinterland as a whole becameProto-Tibetan Plateau, benefit to the oil-gas reservation更多还原