中文摘要：

湖相碳酸盐岩在柴达木盆地西部古、新近系地层中广泛出露,在研究区西岔沟地区主要分布在下干柴沟组、上干柴沟组的顶部,下油砂山组及上油砂山组的底部。通过实测西岔沟剖面、岩性分析、岩相组合特征、生物特征、沉积构造、室内薄片鉴定等研究对西岔沟剖面的碳酸盐岩进行了分析,识别出西岔沟剖面的碳酸盐岩的类型主要有鲕粒灰岩、介壳灰岩、藻叠层石灰岩、泥晶灰岩、砂质灰岩等,沉积环境主要属滨浅湖,并在岩石学特征的基础上对其成因进行了研究。

英文摘要：

Paleogene and Neogene lacustrine carbonate rocks are widely outcropped in the western Qaidam Basin.They are mainly distributed in Xiaganchaigou Formation,the top of Shangganchaigou Formation,Xiayoushashan Formation,the bottom of Shangyoushashan formation in Xichagou area.Based on the measured section,lithologic analysis,lithofacies assemblages,biological characteristics,sedimentary structures and thin section identification,the authors analyzed carbonate rocks of Xichagou section.The results show that the types of carbonate rocks are mainly oolitic limestone,shell limestone,algal-stromatolite limestone,micritic limestone and arenaceous limestone,with the depositional environment being mainly littoral and shallow lake.The genesis of the carbonate rocks are also analyzed on the basis of petrology.