Uranium Deposits Short Course
Recent and Not-So-Recent Developments in Uranium Deposits and Implications for Exploration – Michel Cuney & Kurt Kyser
GeoTotal Group mineral exploration management consultants have decades of international experience in the exploration for all types of uranium deposits.
GeoTotal Group Ltd. mineral exploration consultants are experts in the exploration for uranium deposits, education and training, metallogeny, mineral deposits studies, and the development scientific solutions.
Kurt Kyser co-authored this uranium deposit short course publication that was cosponsored by the Society for Geology Applied to Mineral Deposits (SGA) and MAC, is to highlight data and research that have developed over the past 30 years, as well as discuss new techniques and ideas that can be integrated into effective exploration strategies for uranium. A short course in 1978 sponsored by the MAC is included in this volume as a base on which to build the developments over the last thirty years. New models developed for different deposits and the mechanisms that control their genesis are central themes in this new short course volume.
Uranium Deposit Short Course Table of Contents
- The Effect of Economic and Research Factors in Understanding Uranium Exploration and Discovery of Deposits
- Geochemical Characteristics of Uranium and Analytical Methodologies
- Deposits Related to Magmatic Differentiation
- Deposits Related to Partial Melting
- Deposits Related to Na-Metasomatism and High-Grade Metamorphism
- Hydrothermal Uranium Deposits Related to Igneous Rocks
- Unconformity-Related Uranium Deposits
- Sandstone-Hosted Uranium Deposits
- Other Types of Uranium Deposits
- Implication for exploration strategies
This volume is divided into the following chapters:
Introduction discusses the discovery and properties of uranium, which countries have the greatest reserves and which use nuclear energy, what are the types of deposits and in which geological environments are they found.
Economics and Research describes the interplay between the market price of uranium and the exploration and research that have occurred during the past thirty years. As a commodity, interest in uranium is driven by the spot price of uranium, and vice versa, although the spot price serves as a guide for the value of uranium because not anyone can simply purchase it. Most of the uranium sold for use in reactors is brokered through long-term contracts.
Geochemistry of Uranium consists of a brief review of the geochemical properties of uranium that figure greatly in the development of uranium deposits. Our goal here is not to discuss in detail the geochemistry of uranium, which is not very well known except by those in the processing or disposal industries, but to present an overview of the characteristics of uranium in natural fluids at a variety of temperatures.
Magmatic Differentiation describes uranium mineralization generated by high temperature magmatic processes related to peralkaline magmas and granitoid rocks in migmatitic environments such as alaskite and carbonatite bodies. Extreme fractional crystallization of peralkaline magmas can lead to the formation of very large low-grade U and Th resources because of the high solubility of U and Th in highly depolymerized magmas.
Partial melting discusses the effects of crustal melting processes on the production of melts that host uranium mineralization.
Metasomatic Deposits is concerned with high temperature hydrothermal processes associated with regional Na metasomatism and quartz dissolution, forming discontinuous occurrences of uraniferous Na metasomatized granite, metasedimentary or metavolcanic units that extend over several tens of kilometres.
Hydrothermal (granite-related and volcanic related) Deposits is concerned with a diverse category of deposits generally exhibiting veintype morphology, but also as disseminated ore in syenitic bodies. They may be hosted by granite, volcanic rocks or without any direct relation with granite. High-temperature hydrothermal deposits can also be associated with IOCG-type deposits.
Unconformity-related Deposits examines uranium mineralization related to a reduction front near the unconformity between Proterozoic sandstone units and underlying metamorphosed basement lithologies. The deposits are structurally hosted either in the basement or in the overlying sandstone. Models involving the source of uranium from breakdown of uranium-bearing phases in altered basement rocks along fault zones or from an oxidized basinal brine carrying uranium leached from detrital phases are also discussed, as are the role of paleoaquifers in the prospectivity of a basin.
Sandstone-hosted Deposits discusses breccia pipes and sandstone-hosted low-temperature deposits such as roll-front, tabular and sedimentary copper associated deposits. These occur in medium to coarse-grained sandstone deposited in a continental fluvial or marginal marine sedimentary environment such that impermeable shale/mudstone units immediately above and below the mineralized sandstone confine fluid flow so that uranium can precipitate under reducing conditions within the sandstone because of carbonaceous material, sulfides, hydrocarbons and interbedded basic volcanic rocks with abundant ferromagnesian minerals.
Other types of deposits examines the Elliot Lake quartz pebble conglomerate deposits in Canada and the Witwatersrand gold/uranium deposits in South Africa, the latter a resource of increasing importance. Also discussed are surficial deposits that include the young nearsurface uranium concentrations in sediments and soils, with those in calcrete being the largest deposits.
Implication for exploration strategies briefly discusses what we have learned during the past thirty years that may help us to explore for uranium deposits.
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James Marlatt, PhD, MBA, P.Eng.