Results 81 to 90 of about 516 (108)
Some of the next articles are maybe not open access.
Journal of Geochemical Exploration, 1995
Abstract The acid insoluble residue of twenty-nine gold-bearing and ten barren jasperoids from Carlin, Nevada, were analysed by electron paramagnetic resonance powder spectroscopy (EPR), and by simultaneous proton-induced X-ray emission (PIXE) and proton-induced gamma ray emission (PIGME) spectroscopy.
J.C. van Moort +2 more
openaire +1 more source
Abstract The acid insoluble residue of twenty-nine gold-bearing and ten barren jasperoids from Carlin, Nevada, were analysed by electron paramagnetic resonance powder spectroscopy (EPR), and by simultaneous proton-induced X-ray emission (PIXE) and proton-induced gamma ray emission (PIGME) spectroscopy.
J.C. van Moort +2 more
openaire +1 more source
Dolomite and jasperoid in the Metaline District, northeastern Washington
Economic Geology, 1938The replacement ore bodies of the Metaline zinc-lead district, in northeastern Washington are limited to the greatly disturbed fault block through which the Pend Oreille River flows and are associated with the major faults but are not in them. They are mostly near the top of the Metaline limestone, of Middle Cambrian age, and below black Ordovician ...
openaire +1 more source
Geochimica et Cosmochimica Acta, 2020
Abstract This study examines the whole-rock geochemistry, Fe-oxide texture and crystal morphology, and Fe-oxide (U-Th)/He date variation of jasperoids, as well as the relationships between these characteristics, in order to evaluate jasperoids as an indicator for gold mineralization.
Dante E. Huff +3 more
openaire +1 more source
Abstract This study examines the whole-rock geochemistry, Fe-oxide texture and crystal morphology, and Fe-oxide (U-Th)/He date variation of jasperoids, as well as the relationships between these characteristics, in order to evaluate jasperoids as an indicator for gold mineralization.
Dante E. Huff +3 more
openaire +1 more source
International Journal of Environmental Analytical Chemistry, 2020
Older and younger granites mainly represent gable El-Missikat in addition to red and black jasperoid veins.
Hamdy A.M. Awad +3 more
openaire +1 more source
Older and younger granites mainly represent gable El-Missikat in addition to red and black jasperoid veins.
Hamdy A.M. Awad +3 more
openaire +1 more source
Mapping of jasperoid in the Cedar Mountains, Utah, U.S.A., using imaging spectrometer data
International Journal of Remote Sensing, 1995Abstract Jasperoid, an important indicator of disseminated gold deposits, is mapped in the Cedar Mountains, Utah U.S.A. using data gathered by the Airborne Visible Infra-Red Imaging Spectrometer (AVIRIS). Ratio analysis is employed to detect the sharp rise in reflectance between 1000 nm and 1700 nm in the jasperoid spectrum due to iron absorption at ...
openaire +1 more source
Jasperoid as a Guide to Mineralization in the Taylor Mining District and Vicinity near Ely, Nevada
Economic Geology, 1974Samples of mineralized jasperoid from the central part of the Taylor silver mining district, near Ely, Nevada, and of unmineralized jasperoid from outlying bodies exhibit characteristics that seem to be useful as guides to the center of mineralization and also to clarify the genesis of the ore deposits.
T. G. Lovering, A. V. Heyl
openaire +1 more source
Jasperoid float and stream cobbles as tools in geochemical exploration for hydrothermal ore deposits
Journal of Geochemical Exploration, 1981Abstract Fragments of silicified rocks that are associated with deposits of base and precious metals may be transported as cobbles and pebbles in alluvium far downstream from the source outcrop. These rocks commonly exhibit certain characteristics which distinguish them from other detrital siliceous material, and may thus serve as a useful tool in ...
openaire +1 more source
1995
Jasperoid, a microcrystalline silica rock, occurs along the crest of the Magdalena Mountains and along the west-facing dip slope. It is the focus of this study because in similar settings in Nevada it is associated with economically important deposits of very fine grained gold.
Jacques Renault +3 more
openaire +1 more source
Jasperoid, a microcrystalline silica rock, occurs along the crest of the Magdalena Mountains and along the west-facing dip slope. It is the focus of this study because in similar settings in Nevada it is associated with economically important deposits of very fine grained gold.
Jacques Renault +3 more
openaire +1 more source
Chemical Geology, 2009
Abstract The age of the Mesoproterozoic Belt Supergroup hosted silver and base metal vein deposits of the Coeur d'Alene mining district in northern Idaho has long been controversial. Evidence for Precambrian mineralization comes largely from many ∼ 1400 Ma Pb model ages for galena throughout the district, and several problematic 1100–1300 Ma 207Pb ...
Robert E. Zartman, Joseph V. Smith
openaire +1 more source
Abstract The age of the Mesoproterozoic Belt Supergroup hosted silver and base metal vein deposits of the Coeur d'Alene mining district in northern Idaho has long been controversial. Evidence for Precambrian mineralization comes largely from many ∼ 1400 Ma Pb model ages for galena throughout the district, and several problematic 1100–1300 Ma 207Pb ...
Robert E. Zartman, Joseph V. Smith
openaire +1 more source
Comparative geochemistry of jasperoids from Carlin-type gold deposits of the western United States
Journal of Geochemical Exploration, 1990Abstract Exploration for Carlin-type gold orebodies in the western United States typically involves sampling and analysis of jasperoid, a distinctive alteration type formed by intense silicification of marine sediments. In this study, rock suites were collected from six orebodies and four similar but barren systems.
openaire +1 more source