Evolution and Later Reformation of Early-Middle Jurassic Coal-Bearing Basins in Western Mongolia—A Case Study from the Shinejinst Basin
作者: 吴根耀 ：中国科学院地质与地球物理研究所;
关键词: 控盆断裂； 盆地演化； 后期改造； 区域构造分异； 找煤方向； 早–中侏罗世； 蒙古西部； Basin-Controlling Fracture； Basin Evolution； Later Reformation； Regional Tectonic Differentiation； Coal-Search Direction； Early-Middle Jurassic； Western Mongolia摘要:
Abstract: Owing to variation of the basement structures, syn-orogenic stress fields and regional tectonic evolution, the Early-Middle Jurassic coal-bearing basins in western Mongoliashow different geometric and kinematic features from the simultaneous molasse basins in easternMongolia. The west segment of the Mongolia-Okhotsk suture is a NW- striking transfer zone, which constraints two transpressional fracture belts developing in western Mongolia. The tran- spressional fracture consists of the oblique thrust with NWW- to nearly E-W-striking, and the NW-orientated oblique thrust-strike slipping fault. The front fault of the oblique thrust controls a coal-forming basin in its lower plate. The ba- sin-controlling fault thrusts north(east)wards, with the basin dynamics resulting from a northward push-compression caused by closure of Tethyan ocean in the end of Early Jurassic in western China and followed continent-continent col- lision. The evolution of the Shinejinst Basin can be divided into three stages, which experiences four episodes of refor- mation after its reversion. The coal-search direction for the Lower-Middle Jurassic large coal fields in western Mongo- lia should be a kind of the South Sub-Basin of Shinejinst Basin, which could be indicated by three characters: 1) the basin-controlling faults being NWW- to nearly E-W-striking oblique thrust as well as NE-striking sinistral shearing fault, 2) to be situated at upper side of normal fault in Early Cretaceous extension, and 3) to be located along the piedmont belt of thrust or foothill of range in the Cenozoic uplifting.
文章引用: 吴根耀 (2013) 蒙古国西部早–中侏罗世含煤盆地的演化和后期改造—以希奈金斯盆地为例。 地球科学前沿， 3， 253-266. doi: 10.12677/AG.2013.34035
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