东川矿区“小溜口组”地层特征及与因民组的接触关系  

STRATIGRAPHIC CHARACTERISTICS OF“XIAOLIUKOU FORMATION”AND ITS CONTACT RELATION WITH YINMING FORMATION IN DONGCHUAN MINING DISTRICT

作　　者：李天福 

机构地区：[1]西南有色金属地勘局三一四队

出　　处：《云南地质》1993年第1期1-11,共11页Yunnan Geology

摘　　要：东川矿区落因背斜轴部中元古界昆阳群因民组之下发现一套浅变质的海相钠质火山-沉积岩系(暂名“小溜口组”),用Sm-Nd法测得火山岩的同位素年龄为2324Ma。从火山岩的岩石化学、稀土元素、微量元素等特征看,它和中元古界昆阳群差异明显。“小溜口组”与上覆因民组之间多数为不整合接触,仅在落雪人民凹2800坑道见断层接触。A suite of sodic volcanic-sedimentary rock series of marine facies me-tamorphosed at low-grade was discovered under the Yinming Formation of the Kunyang Group of Middle Proterozoic Era, on the axis of Luoxue-Yin-ming anticline, in the Dongchuan Mining District. Its Sm-Nd istopic age is 2324Ma. Petrochemical characteristics, rare earth elements and trace elements in the volcanic strata are apparently different with the Kunyang Group. Contact relations between“Xiaoliukou Formatiom”and the Yinming For-mation of the Kunyang Group are of unconformity almost everywhere in the area except of fault-contact in ftemingwa tunnel, Luoxue.

关 键 词：地层 小溜口组 因民组 沉积岩 

分 类 号：P53[天文地球—古生物学与地层学]