Peneconcordant deposits

The term stack deposit was first used to describe uranium ore deposits associated with peneconcordant deposits in the Grants Mineral Belt, New Mexico. Stack deposits are also called tecto-lithologic , redistributed or post-fault ore because they represent uranium that was mobilized from earlier peneconcordant or roll-type occurrences and redeposited in near-vertical bodies. The geometry of stack deposits commonly is controlled by faults or fractures that post-date the formation of the other uranium deposits. Stack deposits generally have greater thicknesses than the associated peneconcordant or roll-type deposits, but their shape is irregular. 

Peneconcordant uranium deposits are those that generally lie parallel to bedding in nearly flat-lying sandstones, but in detail they are locally discordant. In cross-section they may be tabular, lenticular or irregular in plan they are equidimen-... 

Low-grade uranium deposits occur in the Quaternary alkaline volcanics of northern Latium (Fig. 10). Thin stratiform peneconcordant uranium mineralization is found in reworked loose tuffaceous deposits and, locally, in diatomite layers. Widespread kaolinization and pyrite-marcasite mineralization occur in the host volcanic beds." Uranium mineralization is related to the supergene environment. 

---