塔东地区寒武—奥陶纪岩相古地理分析

通过钻井资料以及露头资料的详细分析,在塔东地区寒武系—奥陶系识别出盆地相、斜坡相、台地相。根据盆地相沉积特征把塔东地区盆地相分为碳酸盐岩盆地、混积盆地、页岩-硅岩盆地三种类型。碳酸盐岩盆地相岩石类型为碳酸盐岩,混积盆地岩石类型为碳酸盐岩与页岩及硅岩互层,页岩-硅岩盆地岩石类型为泥页岩以及硅质岩。台地区发育台地边缘灰泥丘相、台缘滩相、开阔台地相等。灰泥丘主要为藻凝块岩,滩相主要为颗粒灰岩。综合塔里木盆地寒武纪—奥陶纪沉积特征提出了塔东地区碳酸盐岩沉积综合模式,并指出由台地至盆地方向,盆地由碳酸盐岩盆地向混积盆地及页岩-硅岩盆地过渡。在单井分析、露头资料分析、地震剖面分析的基础上,分析了塔东地区寒武纪—奥陶纪古地理展布。

Lithofacies Paleogeography of Cambrian-Ordovician, Eastern Tarim Basin

Based on analysis of wells and outcrops,basin facies,ramp,plateau facies are identified in Cambrian-Ordovician,Eastern Tarim Basin.With different lithology features,basin facies include carbonatite basinal facies,blending basinal facies and shale-silicate basinal facies.Rock types of carbonatite basinal facies are limestone and dolomite,carbonatite and mud shale of blending basinal facies,mud shale and silica rock of shale-silicate basinal facies.In addition,lime mud mound,sands in platform edge,open platform,tidal flat are included in platform.Rock types of lime mud mound are algal limestone and clotted limestone,and psammitic limestone and oolitic limestone of sands.With multidisciplinary analysis on sedimentation features of Cambrian-Ordovician in Eastern Tarim Basin,depositional model is advanced.With the depth of water increasing,carbonatite basinal facies evolved to blending basinal facies and shale-silicate basinal facies.Based on analysis of single wells,outcrops and seismic,paleoreconstruction has been completed.