论文部分内容阅读
通过对青藏高原腹地不同构造部位的班戈、雄梅、羊八井、拉萨花岗岩和甲岗、曲水花岗闪长岩的热年代学分析,剖析了青藏高原腹地构造-热事件与构造-地貌演化过程。结果表明,青藏高原腹地自中生代中、晚期以来发生4期重大区域性构造-热事件,包括121～116Ma沿班公—怒江缝合带发生的强烈中酸性岩浆侵位事件、93～45Ma沿雅鲁藏布江缝合带北缘发生的强烈中酸性岩浆侵位事件和随后发生于78～40Ma的快速隆升事件、25～15Ma沿冈底斯构造-岩浆带发生的强烈构造隆升事件及8～6.5Ma以来在拉萨地块中部发生的区域性伸展裂陷-差异隆升事件。区域性剥蚀夷平事件主要发生于40～25Ma与15～8Ma,区域性整体隆升主要发生在中新世早、中期即25～8Ma,区域性伸展裂陷与差异升降事件的开始时代约为8～6.5Ma。
Based on the geochronology analysis of Bangge, Xiongmei, Yangbajing, Lhasa granite and Jiguan granite dikes with different tectonic positions in the hinterland of the Qinghai-Tibet Plateau, the tectono-thermal events and tectono-geomorphology in the hinterland of the Qinghai-Tibet Plateau are analyzed Evolutionary process. The results show that there are four major regional tectono-thermal events in the hinterland of the Qinghai-Tibet Plateau since the middle and late Mesozoic, including the intense magmatic emplacement event occurring along the Baogong-Nujiang suture zone during 121 ~ 116 Ma. The 93 ~ 45Ma suture along the Brahmaputra A strong magmatic emplacement event in the northern margin of the belt and a rapid uplift event that occurred in the later 78 ~ 40Ma, a strong tectonic uplift event in the Gangdese tectonic-magmatic belt from 25 to 15Ma, Regional stretch rifting in central Lhasa block - differential uplift. The regional eroded and flattened events occurred mainly in 40 ~ 25Ma and 15 ~ 8Ma. The regional uplifting occurred mainly in the early and middle Miocene, ie, 25 ~ 8Ma. The beginning of regional extensional rifting and differential elevation events was about 8 ~ 6.5Ma.