华北地台北缘西段主要成矿系统分析

研究了华北地台北缘地质演化、构造分区, 从南到北依次为乌拉山-色尔腾山-大青山陆内隆起区、东升庙-渣尔泰山陆内裂陷区、狼山-石哈河陆缘隆起区、霍各乞-白云鄂博陆缘裂陷区、白乃庙-白银都西隆起裂陷带、温都尔庙-爱力格庙裂陷带、苏左旗-锡林浩特槽内隆起区.分析了陆缘基底建造和裂谷沉积建造, 划分出裂谷裂陷期和沉降期沉积.研究了成矿系统, 以成矿物质来源的同一性和继承性划分出3个成矿系统: (1) 变质岩金矿成矿系统, 以绿岩建造为物源基础, 有多种矿床类型组合, 主要产于古陆隆起带的变质岩区. (2) 海相火山细碧岩及喷流沉积成矿系统, 主要产于裂谷裂陷期形成的火山岩建造中, 与火山活动岩浆同期的热水喷流有关, 有铜、铅、锌多金属矿床. (3) 碱性-碳酸岩及喷流叠生成矿系统, 产于白云鄂博裂谷早期碱性-碳酸岩火山岩中, 其中伴随高温硅钾热水喷流沉积, 形成稀有-稀土-铁叠生矿床.主、东矿床新生代以来经受了强烈风化剥蚀, 并有冲积富集现象. 

ANALYSIS OF MAJOR METALLOGENIC SYSTEMS IN WESTERN SECTION, NORTHERN MARGIN OF NORTH CHINA PLATFORM

This paper addresses the geological evolution and tectonic zonation of the northern margin of North China platform where are successively distributed from the south to the north the Wulashan Seertengshan Daqingshan intracontinental upwarping zone, the Dongshengmiao Chaertaishan intracontinental rift, the Langshan Shihahe pericontinental upwarping zone, the Huogeqi Bayan Obo pericontinental rift, the Bainaimiao Baiyindusi rift and upwarping zone, the Wenduermiao Ailigemiao rift. This paper analyzes the pericontinental basement formation and rift sedimentary formation, classifies the rift sedimentation during the splitting and subsiding periods. In addition, this paper deals with the metallogenic system. The identity and the successiveness of the metallogenic material sources are used for the classification of the metallogenic system as four subsystems as shown below: (1) The metallogenic system of metamorphic gold deposit established on the basis of material sources of greenstone formation and composed of various ore deposit type assemblages. This system occurs mainly in the metamorphic area of the upwarping zone in the palaeo continents. (2) The SEDEX metallogenic system in the marine volcanic spilite. This system, mainly composed of Cu Pb Zn polymetallic deposits and mainly occurring in the volcanic rock formation shaped during the rift splitting period, is related to the hydrothermal erupting in the same period of magmas produced in the volcanic activity. (3) The metallogenic system of the spout telescoped deposit in the alkaline rock and carbonatite. This system occurred early in the alkaline volcanic carbonatite of the Bayan Obo rift, with the spout sediments of high temperature silica potassium hydrothermal solution, resulting in the rare element REE iron telescoped deposits. The main ore deposit and the east ore deposit underwent strong weathering and denudation, and alluvial enrichment occured since Cenozoic era.