陕北地区奥陶纪马家沟组五段沉积时期岩相古地理演化*
曹红霞1, 李文厚2, 吴海燕1, 王振国1, 武渝1, 任星民1

Lithofacies palaeogeography evolution of the Member 5 of Ordovician Majiagou sedimentary stage in northern Shaanxi Province
Cao Hong-Xia1, Li Wen-Hou2, Wu Hai-Yan1, Wang Zhen-Guo1, Wu Yu1, Ren Xing-Min1
陕北地区马家沟组五段沉积特征 a—A930井,3912.9m,黑褐色泥质云岩;b—A265井,2892.2m,褐色膏斑云岩,发育膏斑溶孔;c—A451井,2976.6m,灰白色膏盐岩,块状构造;d—A579井,4016.4m,浅灰色岩溶垮塌角砾岩;e—A579井,4015.9m,垮塌角砾岩,见变形层理;f—A265井,2885m,深灰色藻云岩,见包卷层理;g—B56井,3367.3m,深灰色泥云岩夹白色膏岩;h—A568井,2749m,灰白色云岩,见鸟眼构造;i—A557井,3262.1m,灰色云岩,见示顶底构造;j—A225井,2877.2m,灰色云灰岩,见缝合线;k—A432井,2895.9m,深灰色粉晶 云岩,见白色石膏充填孔隙;l—A1038井,2431.9m,砂屑灰岩与泥灰岩互层,发育水平层理,见微裂缝充填方解石