【摘要】 对西藏羌塘盆地东部边缘贡日地区产出石油沥青脉的中侏罗统布曲组的沉积相和沉积环境进行了详细研究,共区分出9种碳酸盐岩微相类型,即灰泥灰岩、纹层状粉泥晶灰岩、砂屑灰岩、球粒泥亮晶泥粒灰岩、含核形石和团块泥粒灰岩、生物碎屑泥粒灰岩、生物碎屑粒泥灰岩、含鲕粒生屑颗粒灰岩、含生物碎屑灰泥灰岩。根据微相类型组合特征和野外沉积构造,认为布曲组灰岩主要形成于碳酸盐台地浅缓坡、中缓坡和深缓坡3种沉积环境,在布曲组内共识别出4个沉积旋回,组成一个相对海平面逐渐上升的海进序列,与上覆地层布曲组岩层构成一个完整的三级海平面变化旋回。更多还原

【Abstract】 In the present paper, the Middle Jurassic Buqu Formation section containing asphaltum vein is studied in the Gongri area, eastern part of Qiangtang basin, Tibet,nine main types of carbonate micro-facies are distinguished in the deposits. They are lime marl, lamellar power-micrite limestone, calcarenite, pellet micrite-sparite packstone,oncoid lump packstone,bioclastic packstone, bioclastic wackstone, oosparite grainstone, bioclastic line marl. According to microfacies assemblage and sedimentary structure, carbonate rock of Buqu Formation mainly form three sedimentary environments: inner ramp, middle ramp and deep ramp. Four sedimentary cycles are recognized in the Buqu Formation, which constitue of a transgressive sequence, which is composed of entire sea-level cyclic sequence.更多还原