摘要
通过磷灰石裂变径迹年龄的测定以及时间-温度热历史的反演,揭示了秭归盆地中新生代构造-热演化过程。结果表明:秭归盆地自120 Ma左右开始缓慢隆升,主要经历了3个强烈的隆升阶段:(1)晚白垩世100~80 Ma开始强烈隆升,是燕山期造山运动在该地区作用的结果,也可能是黄陵背斜晚白垩世强烈抬升向西延伸的响应;(2)晚始新世40 Ma的强烈隆升,可能是印度板块和亚欧板块碰撞初期作用的远程响应;(3)中新世中期到末期10~5 Ma的强烈隆升,是青藏高原东部边界向东扩展及亚洲季风气候变化的响应。秭归盆地内部自白垩纪以来一直隆升剥蚀,展现出与盆地边缘构造-热演化的差异。通过与黄陵背斜东部的当阳盆地构造-热事件的对比,暗示了黄陵背斜在晚白垩世已隆升剥露至地表,分割了两个盆地。晚侏罗世—早白垩世,秦岭大规模挤压变形逆冲推覆构造作用使得米仓山—汉南隆起和黄陵背斜地区成为中上扬子地区磷灰石裂变径迹年龄相对最大的区域,江南—雪峰陆内造山作用向西北方向的扩展使得湘鄂西地区向川东地区磷灰石裂变径迹年龄具有整体变年轻的趋势。晚白垩世以来太平洋板块俯冲挤压效应使得川东褶皱带周缘及川东北磷灰石裂变径迹年龄自南东向北西方向减小,江汉盆地、当阳盆地及龙泉山以西记录的年轻的磷灰石裂变径迹年龄则与青藏高原隆升及其向南东方向构造逃逸的挤压作用和亚洲季风等气候变化的影响有关。
Based on the apatite fission-track dating evidence and modeled time-temperature thermal history, the Mesozoic- Cenozoic tectonic-thermal evolution was quantitatively studied in the Zigui Basin. The results indicate that the uplift of the Zigui Basin began slowly around --120 Ma and continued through three stages; （1） strong uplift during about 100- 80 Ma, resulting from the Yanshanian orogeny and Huangling anticline westward extension since the Late Cretaceous; （2） uplift during the late Eocene around 40 Ma, associated possibly with the collision between the Indochina block and Eurasian plate; and （3） strong uplift during the middle and late Miocene around 10 - 5 Ma, accompanied by the eastward growth of the Tibet Plateau and Asian monsoon climate change. Although there were continuing uplift and denudation since the Cretaceous in the internal Zigui Basin, they differed from the tectonic-thermal evolution at the basin margin. Comparing with the Dangyang Basin located in the east of Huangling, the results indicate that Huangling had exposed to the surface since Late Cretaceous which resulted in the separation of these two basins. During the Late Jurassic Early Cretaceous, large-scale extrusion deformation and thrust-nappe structure in the Qinling Mountains contributed to the relatively older ages of AFT in the Micang Mountains and Huangling anticline among the Middle- Upper Yangtze Block; while the Jiangnan- Xuefeng orogeny extending to the northwest resulted in the younger ages of AFT as whole from western Hubei-Hunan to eastern Sichuan. Similarly, the subduction of the Pacific plate since the Late Cretaceous caused AFT ages younger from southeast to northwest in the eastern Sichuan fold belt and northeastern Sichuan; and the young AFT age in the Jianghan and Dangyang basins west of the Longquan Mountains resulted from the uplift of the Tibet Plateau, southeastward escaping extrusion and change of the Asian monsoon.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2017年第3期116-126,共11页
Earth Science Frontiers
基金
国家自然科学基金项目(41372140
40902038)
湖北省杰出青年基金项目(2016CFA055)
武汉市科技晨光计划项目(2016070204010145)
中央高校基本科研业务费专项资金资助项目(CUG201536)
关键词
裂变径迹
秭归盆地
构造-热演化
中新生代
中上扬子
fission track
the Zigui Basin
tectonic-thermal evolution
Mesozoic- Cenozoic
the Middle- Upper Yangtze block
