高校地质学报2023，Vol.29Issue(6)：872-885,14.DOI:10.16108/j.issn1006-7493.2022057
青藏高原东缘中新生代隆升及构造扩展方式转换
Meso-Cenozoic Uplift and Transformation of Tectonic Extension Mode in the Eastern Margin of Qinghai-Tibet Plateau
摘要
Abstract
In order to analyze changes in of tectonic deformation and extension mode during the process of eastward compression of Qinghai-Tibet Plateau,the eastern edge of Qinghai-Tibet Plateau is selected as the study area,and apatite/zircon fission track studies were carried out.The results show that many differences between the Zoige Basin and the Longmenshan Block in the aspect of low-temperature geochronology and tectonic uplift:the cooling rates of several samples in the Zoige basin are relatively stable,ranging from 1.257℃to 1.285℃/Myr,while the cooling rates of several samples in the Longmenshan Block changes greatly,ranging from 1.243℃to 2.875℃/Myr;Zoige Basin has experienced two obvious tectonic thermal events since 100 Ma with the first in 100-80 Ma(cooling rate is 4.40±0.395℃/Myr)and the second in 21-12 Ma(cooling rate is 2.89±0.597℃/Myr).The eastern edge of Longmenshan Block has generally shown a gradual increase in the degree of tectonic uplift since 70 Ma,and the uplift has continued to increase since 8 Ma with the cooling rate of 5.75±0.238℃/Myr;The tectonic deformation of Zoige Basin can be classified as forward expansion,while the Longmenshan Block has backward expansion(especially since 8 Ma).The process mentioned above is summarized as"reflection and refraction of tectonic expansion",the"reflection tectonic stress"reached current location of Longriba fault in Pliocene(about 4.48 Ma),with the result of the Longriba fault zone with the features of both thrust and dextral strike slip.关键词
裂变径迹/前展式/后展式/构造隆升/青藏高原Key words
fission track/piggyback propagation/overstep propagation/tectonic uplift/Qinghai-Tibet Plateau分类
天文与地球科学引用本文复制引用
金文正,白万奎,叶治续..青藏高原东缘中新生代隆升及构造扩展方式转换[J].高校地质学报,2023,29(6):872-885,14.基金项目
国家自然科学基金项目(41002072) （41002072）
油气资源与探测国家重点实验室开放课题基金(PRP/open-1307) （PRP/open-1307）
云南省科技计划项目(202302AF08001)联合资助 （202302AF08001）
