摘要
近年来,在世界许多古老地台区的下元古宙地层中发现了大量铀矿床。连山关地区具有与澳大利亚、加拿大等国家前寒武纪铀矿床类似的某些地质条件。目前已在太古宙花岗杂岩体与下元古宙沉积变质岩系接触带附近发现一些矿化现象,并且找到一处铀矿床。本文根据历年工作成果,着重讨论该矿床的成矿地质条件,矿化特征及成矿模式等问题。
The rock containing the uranium deposit occurred in Lianshangan region in the northeastern part of Northern China Platform consists of Archaean granitic complex and early protcrozoic mctase-diments with the latter unconformably overlying on the Archaean basement.Uranium mineralization is located in and around the tectonic contact zone between the Archean granite ane early protcrozoic metasediments. There are three types of uranium mineralization. The first type is of low tenor and is impregnated in quartzite and schist distributed outside the tectonic contact zone. The second type is a breccia ted rich ore and occurs within the alkalic metasomatite which directly sits in the tectonic contact zone. The third type is small veins and occurs in the fissures of the altered granite inside the tectonic contact zone. According to their genesis the uranium mineralization is divided into three type, namely.- meta sedimentary, alkalic meso-hypothermal metasomatic fissure filling, and alkalic meso- epithermal fissure filling, u-pb isotopic dating of the three type are 2114m. y. 1891m. y. and 1829m. y respectively. The mineral composition of the uranium ore is rather simple, ' The main economic minerals are pitchblende and uraninite.The location of the uranium ore body is controlled by the processesof sedimentation, regional metamorphism and tectonic fracturing. The form of uranium mineralization is closely related to the alkalic metasomatism leading in the tectonic movement in the age of 1800-1900m. y When the Re-emplacement of the granitoid basement took place.The uranium came from both the granite and the metasediments of this region. Which had higher uranium content. The uranium deposit thus posseses multistage and poly-genetic charactcristiacs.
出处
《吉林大学学报（地球科学版）》
EI
CAS
1982年第S1期84-95,168,共13页
Journal of Jilin University：Earth Science Edition
