摘要
年代学与钕模式年龄资料表明，红河成矿带的哀牢山群和瑶山群深变质岩系属同一地层系列，主体部分形成时代为１．３５—１．７Ｇａ，但也存在晚元古代斜长角闪岩。该区不存在太古宇基底。介于哀牢山群和瑶山群之间的浅变质岩系为前寒武纪火山岩与大理岩，并夹杂印支期洋中脊玄武岩（ＭＯＲＢ）型火山岩，表明原区调队填图时将其划分为三叠纪地层是不正确的。该区晋宁期（８００—９００Ｍａ）、印支期（２６５Ｍａ）、燕山期（７５—１１５Ｍａ）与喜山期（２８—３５Ｍａ）构造与动力变质事件十分强烈。年代学与地质观察证据表明，该区岩石为构造岩片组成，无正常地层系列，应称哀牢山岩群。铜成矿作用主要发生在晋宁期，在印支期、燕山期和喜山期存在铜矿的进一步迁移活化富集作用。
Based on geochronological and Nd model age data, it is indicated that the high metamorphic complexes of Ailaoshan and Yaoshan groups have a bulk age range of 1.35—1.7 Ga, and also there existed amphibolites of late Proterozoic. The light metamorphic zone between the Ailaoshan and Yaoshan groups were mainly composed of Precambrian volcanic rocks and marbles, as well as mingled with MORB of early Indo-Chinese period, which indicated that the initial division of strata proposed by The Yunnan Geological Survey, a suit of Triassic strata, was incorrect. The strong tectonic movements and dynamic metamorphism were occurred during Jinning(800 — 900Ma), Indo-Chinese (265 Ma), Yanshanian (75 — 115 Ma) and Himalayan (28 — 35 Ma) periods. The evidence from geochronology and geological observation shows that the rocks in this area are mainly tectonic rock fragments, instead of normal stratum series, which should be named as the Ailaoshan rock group. Copper mineralization was mainly occurred during Jinning period, and there were Cumigration, reactivation and enrichment during Indo-Chinese, Yanshanian and Himalayan periods.
出处
《地球化学》
CAS
CSCD
北大核心
1997年第2期46-56,共11页
Geochimica
基金
国家科学技术委员会攀登计划
中国有色金属工业总公司地质勘察局联合资助
关键词
地质年代学
成矿作用
壳幔演化
成矿带
geochronology, Proterozoic, mineralization, Yunnan Province
