板桥—北大港地区沙一段发育多层碳酸盐岩沉积，岩性主要为生物灰岩、鲕粒灰岩、白云质灰岩、泥灰岩，形成碳酸盐－陆源碎屑混积岩，既有成分上的混积，也有纵向地层剖面上的混积层序。北部受物源影响含陆源碎屑较多，主要为碳酸盐与砂、泥岩混积，成分上以灰质粉砂岩和灰质砂岩为主；南部主要为碳酸盐与泥、页岩混积，成分上以灰质页岩为主。沉积相类型有滨浅湖、浅湖、半深湖等，其中生物浅滩、鲕滩等微相具有较好的油气勘探价值。

Carbonate reservoir develops well in the first member of Shahejie Formation in Banqiao-Beidagang area. The lithologies are mainly composed of biogenic limestone, oolitic limestone, dolomitic limestone and marlite, which formed carbonate-siliciclastic mixosedimentite not only in the component but also in the vertical sequence. The sediments in the north mainly have terrigenous clastic, and the mixosedimentite are composed of carbonate rocks, sandstone and mudstone, with the main component of lime-siltstone and lime-sandstone. the mixosedimentite in the south are formed by the carbonate rocks, mudstone and shale, with the main component of limestone shale. The sedimentary facies include shore-shallow lake, shallow lake, semi-deep lake, while the microfacies of biology bank and oolitic beach are more valuable for the oil and gas exploration.