Presents and discusses results of detailed textural examination using scanning electron microscopy on samples from the Giant and Con gold mines, Northwest Territories. The study was a preliminary investigation designed to determine the electrical conductivity mechanisms of the mineralized sericite schist from alteration zones that parallel the gold-bearing quartz veins in the Yellowknife mining district. Results are highlighted for four samples and include schematic representations of rock texture and three-dimensional electrical resistivity. The purpose of the study was to obtain information required to help develop efficient exploration strategies.
Presents and discusses results of effective porosity, bulk density, & electrical resistivity measurements made on samples from the Giant and Con gold mines, Northwest Territories. The samples represent mineralized and non-mineralized sections of the mines' quartz ankerite veins, sericite schist, chlorite schist, and basalt. The objective of the research is to provide basic data to be used in determining the petrophysical characteristics and electrical conductivity mechanism of these rocks, which would give information required to develop exploration strategies for aiding interpretation of electromagnetic survey data.
Formation resistivity factor and pore-surface resistivity values were determined for three mineralized & nonmineralized rock samples from the Giant mine & Con mine areas of the Yellowknife mining district. The purpose was to provide basic information required to understand the electrical conductivity mechanisms of these rocks and to aid interpretation of geophysical surveys conducted in these areas. This paper describes the methods & processes used to obtain the formation factor data & to document the results for use in future studies.
The final year of the Nechako NATMAP project to study the geology of central British Columbia was used to research information collected in the field & laboratory, and to compile & document the study results. This article includes a review of upcoming publications & other products, by type of product: maps, journal articles, conference presentations, and computer products, as well as ongoing research on petrology, palaeontology, terrane characterization, tectonics & structure, and Quaternary geology.
As the importance and dependence of specific mineral commodities increase, so does concern about their supply. The United States is currently 100 percent reliant on foreign sources for 20 mineral commodities and imports the majority of its supply of more than 50 mineral commodities. Mineral commodities that have important uses and face potential supply disruption are critical to American economic and national security. However, a mineral commodity's importance and the nature of its supply chain can change with time; a mineral commodity that may not have been considered critical 25 years ago may be critical today, and one considered critical today may not be so in the future. The U.S. Geological Survey has produced this volume to describe a select group of mineral commodities currently critical to our economy and security. For each mineral commodity covered, the authors provide a comprehensive look at (1) the commodity's use; (2) the geology and global distribution of the mineral deposit types that account for the present and possible future supply of the commodity; (3) the current status of production, reserves, and resources in the United States and globally; and (4) environmental considerations related to the commodity's production from different types of mineral deposits. The volume describes U.S. critical mineral resources in a global context, for no country can be self-sufficient for all its mineral commodity needs, and the United States will always rely on global mineral commodity supply chains. This volume provides the scientific understanding of critical mineral resources required for informed decisionmaking by those responsible for ensuring that the United States has a secure and sustainable supply of mineral commodities.
A well-exposed section about 250 metres wide below the high water line of the Jennings River, Teslin Lake map area in northern British Columbia shows part of the Teslin Fault and provides an opportunity to constrain the fault's kinematic history by direct ground observations. This report describes preliminary structural observations of this section of the Teslin Fault, including the rock types involved, mylonitic & ultramylonitic structures, and deformation. Indications of two main episodes of shearing are discussed.
Describes reconnaissance geological studies conducted in the south-west Nass River area of northern British Columbia. Includes descriptions of the Bowser Lake Group of sedimentary rocks, Eocene plutonic rocks, metamorphic rocks, possibly Miocene granite, mafic dykes, and Pleistocene & Recent volcanic strata, as well as the area's structural geology.
Describes a geologic mapping project in the area of the Nechako reservoir in central interior British Columbia. Includes description of regional geology, stratigraphic units, volcanic & plutonic rocks, and geologic structure. Evidence for two periods of deformation of Hazelton Group rocks in the study area is discussed.
