Publications

Aeromagnetic and radiometric data were used to map shallow Precambrian basement lithology and structure and determine the depth to magnetic basement, which in most cases, corresponds to the depth to crystalline basement of interest for mineral exploration. These depths, along with those determined from gravity data, help identify basins with hydrologic potential. In addition, the...

PRISM-I summary documents mention the presence of mafic-ultramafic igneous intrusive rocks in several areas of Mauritania and a number of chromium (Cr) and copper-nickel (Cu-Ni (±Co, Au)) occurrences associated with them. Permissive geologic settings generally include greenstone belts of any age, layered mafic-ultramafic and unlayered gabbro-anorthosite intrusive complexes in cratonic...

This report is a companion to the new Geologic Map of Mauritania (Bradley and others, 2015; referred to herein as “Deliverable 51”) and the new Structural Geologic Map of Mauritania (Bradley and others, 2015a; referred to herein as “Deliverable 52”). Section 1 contains explanatory information for these two digital maps. Section 2 covers the analytical methods used in obtaining new U-Pb...

A hydrogeologic study was conducted to support mineral-resource assessment activities in Mauritania, Africa. Airborne magnetic depth estimates reveal two primary groundwater basins: the porous coastal Continental Terminal Basin (fill deposits); and the interior, fractured interior Taoudeni Basin. In the Continental Terminal Basin, there is uniform vertical recharge and localized...

Previous PRISM reports discuss a variety of industrial minerals. Gypsum, phosphate, salt, stone, sulfur, and ilmenite command the majority of the attention in the earlier geologic reports. (Ilmenite is evaluated in a separate U.S. Geological Survey report in the current study). Asbestos, arsenic, barite, fluorite, and kaolin are listed in indices (occurrence datasets) as potential...

High-grade hematitic iron ores (or HIF, containing 60–65 percent Fe) have been mined in Mauritania from Superior-type iron deposits since 1952. Depletion of the high grade ores in recent years has resulted in a number of new projects focused on lower grade magnetite ores in Algoma-type banded iron formation (or BIF, containing approximately 35 percent Fe). Large deposits of oolitic-type...

Potential for base- and precious-metal-bearing volcanogenic massive sulfide deposits (VMS) exists in Mauritania in the greenstone belts of the southwestern Rgueïbat Shield and in the allochthonous portions of the central and southern Mauritanides. Additional potential exists for VMS deposits within the Tiris Complex of the central Rgueïbat Shield. Volcanosedimentary successions of...

The presence of Neoproterozoic through Cambrian, continental, siliciclastic sedimentary rocks interbedded with dolomitic carbonates, shales, and glacial tillites similar to the Katanga Supergroup host rocks of the Central African Copperbelt and other sediment-hosted copper-bearing Proterozoic sequences worldwide, is first order criteria for consideration of the Neoproterozoic units of...

Although Mississippi Valley-type (MVT) deposits have not been recognized in Mauritania there are permissive tracts for these deposits in the regionally extensive Proterozoic carbonate rocks of the Taoudeni Basin. Permissive tracts for undiscovered MVT Pb-Zn-Ag deposits in the Proterozoic carbonate units are supported by the occurrences of MVT mineral and alteration assemblages, presence...

This study, covering the Bureau of Land Management (BLM) Central Yukon Planning Area (CYPA), Alaska, was prepared to aid BLM mineral resource management planning. Estimated mineral resource potential and certainty are mapped for six selected mineral deposit groups: (1) rare earth element (REE) deposits associated with peralkaline to carbonatitic intrusive igneous rocks, (2) placer and...

The Alaska Division of Geological & Geophysical Surveys (DGGS) and U.S. Geological Survey (USGS) are implementing ongoing programs to characterize the petroleum potential of Cook Inlet basin. Since 2009 this program has included work on the Mesozoic stratigraphy of lower Cook Inlet, including the Middle Jurassic Tuxedni Group between Tuxedni and Iniskin bays (LePain and others, 2013...

Shoreline placer Ti deposits are composed of ilmenite, rutile, zircon, monazite, and magnetite in well-sorted, fine- to medium-grained sand in coastal dunes, beaches and inlets. In addition to titanium, zirconium, in particular, and rare earth elements (REE) have become a major source of value in shoreline placer deposits. Shoreline placer deposits form mostly on tropical beaches around...