葛洲坝水利枢纽一期工程的基础岩石主要有砂岩、粉砂岩、粘土质粉砂岩、粘土岩及砾岩等。其分布情况为,三江以砂岩为主,二江电厂和安装场以砂岩、粉砂岩互层为主,二江泄水闸以粉砂岩、粘土质粉砂岩为主(靠右区有少部分砾岩)。岩层基本为一单斜构造,其走向大致与河流平行(NE20°～40°),倾向 Gezhouba Water Control Project Phase I basic rock sandstone, siltstone, clayey siltstone, clay rock and conglomerate. The distribution is that Sanjiang is dominated by sandstone, the second power plant and installation site are interbedded with sandstone and siltstone, while the second is mainly siltstone and clayey siltstone (a small part of conglomerate near the right ). The rock is basically a monoclinic structure with a strike roughly parallel to the river (NE20 ° ~ 40 °)