湖北长阳资丘二叠纪沉积及演化特征  

Sedimentary facies and evolution of the Permian Ziqiu section in Changyang County,Hubei Province

作　　者：万秋[1] 

机构地区：[1]安徽省地质调查院,安徽合肥230001

出　　处：《地质学刊》2016年第1期7-14,共8页Journal of Geology

基　　金：国家自然科学基金项目(40972082)

摘　　要：湖北长阳资丘二叠系剖面地层出露良好,特征明显,以碳酸盐岩沉积为主。野外剖面测量和室内微相分析表明,二叠系岩相主要由生物碎屑颗粒灰岩、砂屑灰岩、砾屑灰岩、硅质岩、钙质页岩等组成。根据岩相、古生物化石及碳酸盐岩微相分析,研究区二叠系主要为碳酸盐斜坡、台地和盆地沉积。其中,中二叠世发育碳酸盐斜坡沉积和盆地沉积,晚二叠世发育斜坡沉积、碳酸盐台地和盆地沉积。沉积演化表明,该区二叠纪发生了2次海进—海退旋回:第一次海侵发生在栖霞期,茅口期末结束;第二次始于吴家坪初期,持续到长兴末期。在中二叠统栖霞组下部发现了丰富的遗迹化石Zoophycos,形态及沉积构造研究表明此遗迹化石产生于浪基面以下较深水的碳酸盐岩斜坡环境。The Permian Ziqiu section in Changyang County of Hubei Province is well outcropped, with notable characteristics, and is mainly composed of carbonate rocks. Field section measurements and indoor microfaeies analysis suggest that the lithofacies of this sec- tion is dominated by bioclastic grainstone, calcarenite, calcirudite, silica and calcareous shale. A combined analysis of lithofacies, fos- sils and carbonate microfacies indicates that three kinds of sedimentary environments were identified, i.e., carbonate slope, platform and basin deposition. The Middle Permian has mainly deposited on the carbonate slope and basin, and the Upper Permian has mainly deposited on the carbonate slope, platform and basin. The sedimentary evolution indicates that two sedimentary cycles of transgression and regression occurred in the Permian. The first transgression occurred in the Qixia Stage and ended in the late Maokou Stage, while the second transgression occurred in the early Wujiaping Stage and ended in the late Changxing Stage. Abundant trace fossil Zoophycos has been found at the bottom of the upper Qixia Formation, which is considered to be produced in a deep carbonate slope environment below the wave base.

关 键 词：岩相分析 沉积演化 Zoophycos遗迹相 湖北长阳 

分 类 号：P531[天文地球—古生物学与地层学]