Sandstone-Hosted Uranium Deposits as a Possible Source for Critical Elements: The Eureka Mine Case, Castell-Estaó, Catalonia

Abstract

The Eureka deposit in Castell-estaó in the Catalan Pyrenees is a Cu–U–V deposit, hosted by Triassic red-bed sandstones, and classified here as a low-temperature, sandstone-hosted stratabound metamorphite U deposit. The main mineralisation is stratabound, related to coal-bearing units and produced during the Alpine deformation by migration of hydrothermal fluids. In this stage, the original sedimentary and diagenetic components (quartz and calcite, micas, hematite and locally apatite) were replaced by a complex sequence of roscoelite, fine-grained REE phosphates, sulphides and Ni–Co arsenides and sulpharsenides, Ag–Pb selenides, bismuth phases, sulphosalts and uraninite. The black shales of the Silurian sediments underlying the deposit and the nearby Carboniferous volcanoclastic rocks are interpreted as the source of the redox-sensitive elements concentrated in Eureka. The sulphur source is related to leaching of the evaporitic Keuper facies. The REE transport would be facilitated by SO4-rich solutions. The reduction of these solutions by interaction with organic matter resulted in the widespread precipitation of REE and redox-sensitive elements, including many critical metals (V, Bi, Sb, Co), whereas barite precipitated in the oxidized domains. The occurrence of similar enrichments in critical elements can be expected in other similar large uranium deposits, which could be a source of these elements as by-products.

Micro-Mechanisms and Implications of Continental Red Beds

“…Fe and other trace metal elements in the matrix and cement were dissolved in low-pH reduction fluids and eventually reprecipitated near the redox front with fluid transport [93,99,100]. In addition, because the creation of reduction areas usually consumes large amounts of fluids, when they carry dissolved metals such as Cu, U, V, Co, and Au, creating enrich mineralization near redox fronts, geologists often locate copper, uranium, and other sedimentary minerals near the reduction areas [7,15,42,82,[101][102][103][104].…”

Моделирование Движения Жидкостей В Процессе Эксплуатации Скважинного Фонда На Месторождениях Урана, Отрабатываемых Методом Псв

“…В условиях пластово-инфильтрационных месторождений с высокой проницаемостью и с учетом проблематики проведения контроля движения растворов в условиях подземного скважинного выщелачивания сернокислым раствором риск техногенного образования регенерируемых урановых залежей существенно высок [18]. Это обуславливает достаточно перспективный научно-прикладной характер проблемы мониторинга растекания технологических растворов с использованием методов математического моделирования.…”

Distribution of Uranium and Rare Elements in Radioactive Phosphate-Bearing Anomalies in Southeast Mongolia

“…The demand for uranium, rare earth and related rare elements (REE) has increased in recent times to meet new technological requirements and this has increased interest in exploration activity for these elements [6][7][8]. More than 1100 uranium and radioactive anomalies and~300 such zones were discovered during earlier Soviet exploration and more recent exploration undertaken by Western companies.…”