二连盆地巴彦乌拉铀矿床控矿成因相特征及成矿规律研究

Characteristics of ore-controlling genesis facies and metallogenic regularity in Bayanwula uranium ore deposit

巴彦乌拉矿床位于马尼特坳陷的西部,通过对其控矿成因相研究,研究其控矿体系域、控矿沉积体系、控矿结构面等特征,总结其成矿规律。矿床控矿成因相为辫状河—层间氧化型,控矿体系域类型为水退体系域,矿体和异常主要位于进积型、加积型准层序组中。控矿沉积体系为辫状河沉积体系,控矿成因亚相为辫状河道亚相、心滩微相。控矿结构面主要为地球化学结构面和物理结构面,地球化学特征主要为氧化还原地球化学障控矿,横向上主要划分为氧化带、氧化还原过渡带、还原带。通过价态铀分析,认为由于流体动力学变化导致的机械、吸附沉淀对成矿起重要作用。通过控矿成因相研究,希望对巴彦乌拉铀矿床外围及其他区域找矿具有指导意义。

The Bayanwula sandstone type uranium deposit is located in the western part of Manite depression. Based on study of ore-controlling genesis facies, the characteristics of ore-controlling system domain, ore-controlling depositional system, ore-control- ling structures were studied and the metallogenic regularities were summarized. The ore-controlling genesis facies is identified as brai- ded channel river-interlayer oxidation type and the ore-controlling system domain is regressive stage system domain. The ore body and mineralizated anomalies mainly occur in the prograduated and aggradated parasequence set. The ore-controlling depositional system is braided river depositional system, the ore-controlling subfacies is braided river channel, and microfacies is channel bars. The ore-con- trolhng structure surfaces mainly are geochemical and physical structural surfaces. In geochemical characteristics is characterized with the oxidated reduction geochemical barrier which mainly control the deposit deposition. It can be＇subdivided into oxidation zone, redox transitional zone and reduction zone in the horizontal direction. Based on the analysis of valence state uranium, it is thought that the mechanical and adsorption process play an important role for mineralization precipitation due to fluid dynamics changes. Through the ore -controlling genesis facies study, it is valuable for guiding the prospecting in the surrounding area of Bayanwula uranium ore deposit and other areas.