摘要
在中国,业已厘定出准噶尔-天山、阴山-辽河、祁连-秦岭、华南和滇西等五个主要铀矿省。它们大多分布在地台与显生宙活动带的接合部位,在空间上趋附于前震旦纪地体。铀矿省内花岗质岩浆或碱性岩浆活动强烈,并发育有陆架式、裂谷式及陆相磨拉石式等在稳定条件下形成的沉积建造或火山沉积建造。铀成矿作用大多发生在地壳经长期挤压之后出现的拉张陆相环境中,形成于挤压过程中的矿化居次要地位。如果以1.4Ga为界把地壳演化史分为两个巨时域,世界上大部分重要铀矿省都形成于2.8—1.4Ga之间的前一巨时域,这显然与地壳演化的方向性和不可逆性有关;中国已厘定的铀矿省却主要形成于后一巨时域。所以,中国地质学家在已知成矿域内扩大找矿成果的同时,正积极探素圈定主要形成于前一巨时域的铀矿省的可能性。
Five major uranium provinces have been known in China as the Junggar-Tianshan, theYinshan-Liaohe, the Qilian-Qinling, the South China and the West Yunnan, Which occupythe junacticn rcgions of platforms and Phanerozoic mobile zones, Crossing the contacts betweenthem. The provinces are usually characterized by the development of magmatism, tendingto differentiated K-enriched granites and continental acid volcanics or alkaline rocks or deepsource and the deposition of marginal marine shelf, rift valley and molasse facies sediments.Similar to those in the rest of the world, most of uranium deposits discovered in China havebeen shaped under the tensile conditious in the later waning stages of orogenies except so-calledpegmogranite/pegmoalaskite type and Na-metasomatic type deposits which might be producedin compressive environments. On the other hand, nearly all uranium provinces in Chinawere formed during the Late Mega-time-domain (post-1.4Ga), except the Liaodong Block ofYinshan-Liaohe Province and the West Longshoushan of Qilian-Qinling Province, whereasAthabasca, Pine Creek, Olympic Dam and other critically important provinces were formed inthe Early Mega-time-domain (2.8-1.4Ga). Thus, Chinese geologists are attempting to recog-nize new provinces formed in the Early Mega-time-domain in Sino-Korean Platform in ad-dition to continuing prospection within the range of known provinces.
出处
《铀矿地质》
CSCD
北大核心
1990年第6期326-337,共12页
Uranium Geology
关键词
铀矿
分布
中国
China
Geotectonic evolution
Uranium province
Distribution pattern
