论文部分内容阅读
西南地区广泛分布黑色岩系,主要分布于上震旦统—下寒武统、志留系、二叠系和三叠系,其中以上震旦统—下寒武统为主,次为志留系。西南地区黑色岩系中分布有众多的铀矿床、铀矿点和铀矿化点,但铀矿床相对较少。西南地区黑色岩系中典型的矿床有四川若尔盖铀矿床(510)、贵州白马硐铀矿床(504)和广西大新铀矿床(373)。这3个富大铀矿床具有许多相似的特点,与深大断裂有关,也与岩性有关,同时还与岩浆—流体活动有关。西南地区黑色岩系沉积和成岩期初步富集较高含量的铀,是西南地区黑色岩系铀成矿的前奏。后期改造作用和叠加成矿的方式及规模,是西南地区黑色岩系中铀矿大矿和富矿形成的必要条件。西南地区黑色岩系中形成富大铀矿需要经过“三部曲”:①前奏:沉积作用形成铀含量高值区(铀异常),②改造:浅源流体改造形成铀的再富集(出现铀矿点、小型或中型矿床),③叠加:深源流体叠加和改造形成富大矿(大型铀矿床)。
The black rock series are widely distributed in southwest China, mainly distributed in the Upper Sinian - Lower Cambrian, Silurian, Permian and Triassic, of which the above Sinian - Lower Cambrian are the dominant, system. There are many uranium deposits, uranium deposits and uranium mineralization sites in the black rock series in southwest China, but there are relatively few uranium deposits. The typical deposits in the black rock series in Southwest China include the Zuoergai uranium deposit (510), the Guizhou Baimaite uranium deposit (504) and the Guangxi Daxin uranium deposit (373). The three rich uranium deposits have many similar features, which are related to deep faults and lithology, and are also related to magmatic-fluid activities. The deposition and diagenesis of the black rock series in Southwest China initially enriched the higher levels of uranium, which is the prelude to the uranium mineralization of the black rock series in southwest China. The role of post-alteration and superimposition of metallogenic methods and scale are the necessary conditions for the formation of large uranium deposits and rich ore deposits in the black rock series in the southwestern region. Formation of large uranium deposits in the black rock series in the southwestern region needs to go through the “trilogy”: ① Prelude: Sedimentary formation of high uranium content area (uranium anomaly); ② Renovation: Reformation of shallow sourced fluids to re-enrich uranium (With uranium ore spots, small or medium-sized deposits), ③ superposition: superposition of deep-source fluids and transformation to form large ore-rich mines (large uranium deposits).