scholarly journals Diamonds in Alberta: studies of potential host rocks of deep-seated origin and applications of indicator mineral exploration techniques

1997 ◽  
Author(s):  
B A Kjarsgaard
Keyword(s):  
Mineral Exploration ◽  
Potential Host ◽  
Indicator Mineral ◽  
Host Rocks

Shale, mudstone, and claystone as potential host rocks for underground emplacement of waste

1973 ◽  
Author(s):  
E.A. Merewether ◽  
J.A. Sharps ◽  
J.R. Gill ◽  
M.E. Cooley
Keyword(s):  
Potential Host ◽  
Host Rocks

Paragenesis of veins of the Duck Pond tin prospect, Meguma Group, East Kemptville, Nova Scotia

1989 ◽  
Vol 26 (10) ◽  
pp. 2032-2043 ◽  
Author(s):  
Christian V. Pitre ◽  
Jean M. Richardson
Keyword(s):  
Nova Scotia ◽  
Manganese Oxides ◽  
Open Pit ◽  
Granitic Magma ◽  
Sulphide Minerals ◽  
Main Indicator ◽  
Argillic Alteration ◽  
Mineral Assemblages ◽  
Indicator Mineral ◽  
Host Rocks

The Duck Pond tin prospect is a vein- and strata-bound cassiterite prospect that is located 2 km west of the East Kemptville open-pit tin mine in southwestern Nova Scotia. The host rocks of the Duck Pond prospect are interbedded metawacke and meta-argillite that belong to the transition unit of the Meguma Group. These rocks contain quartz, sericite, chlorite, hematite, rutile, manganese oxides, feldspar, and porphyroblastic garnet, but not detrital cassiterite. The prospect is structurally controlled and contains several cross-cutting vein sets that have alkalic, chloritic, or argillic alteration assemblages. Muscovite is the main indicator mineral for alkalic alteration and occurs in veins that contain anorthoclase or quartz. Cassiterite is associated with chloritic alteration and occurs as subhedral to euhedral grains, acicular needles, and colloform layers in veins in meta-argillite and as strata-bound disseminations in metawacke. Most cassiterite precipitated under externally buffered conditions with respect to oxygen. Fe, Cu, Zn, and As sulphide minerals and quartz were deposited during argillic alteration. Late-stage processes such as recrystallization, sulphidation, and oxidation also occurred. Chalcopyrite is replaced by bornite and covellite; pyrite is replaced by marcasite.Unlike the F-rich East Kemptville deposit, fluorine-rich and tin-sulphide minerals are not present in the Duck Pond prospect. Trace tourmaline, absent at East Kemptville, is found at Duck Pond. However, the source of tin-mineralizing fluids at Duck Pond and East Kemptville was likely the granitic magma of the Davis Lake complex, which also hosts the East Kemptville deposit. From the mineral assemblages and textural relationships, it appears that as the temperature dropped from 425–405 °C to less than 200 °C at Duck Pond, the pH dropped from 5.2 to no lower than 3. Log [Formula: see text] dropped from at least −19 to −43. Log [Formula: see text] rose from < −15 to > −10. Cassiterite precipitated at the higher ends of the temperature and pH ranges and the lower end of the log [Formula: see text] range.

Application of indicator mineral methods to mineral exploration

2014 ◽  
Author(s):  
M B McClenaghan ◽  
A Plouffe ◽  
D Layton-Matthews
Keyword(s):  
Mineral Exploration ◽  
Indicator Mineral

scholarly journals Characterizing mineralogy and redox reactivity in potential host rocks for a UK geological disposal facility

2015 ◽  
Vol 79 (6) ◽  
pp. 1353-1367 ◽  
Author(s):  
J. Quirke ◽  
C. M. B. Henderson ◽  
R. A. D. Pattrick ◽  
K. M. Rosso ◽  
A. Dent ◽  
...  
Keyword(s):  
Iron Content ◽  
Host Rock ◽  
Azo Dye ◽  
Total Iron ◽  
Geological Disposal ◽  
Potential Host ◽  
Fine Grained ◽  
Reducing Conditions ◽  
Redox Reactivity ◽  
Host Rocks

AbstractGeological disposal facilities (GDF) are intended to isolate and contain radioactive waste within multiple protective barriers, deep underground, to ensure that no harmful quantities of radioactivity reach the surface environment. The last line of defense in a multi-barrier GDF is the geosphere, where iron is present in the host rock mineralogy as either Fe(II) or Fe(III), and in groundwater as Fe(II) under reducing conditions. The mobility of risk-driving radionuclides, including uranium and technetium, in the environment is affected significantly by their valence state. Due to its low redox potential, Fe(II) can mediate reduction of these radionuclides from their oxidized, highly mobile, soluble state to their reduced, insoluble state, preventing them from reaching the biosphere. Here a study of five types of potential host rocks, two granitoids, an andesite, a mudstone and a clay-rich carbonate, is reported. The bulk rocks and their minerals were analysed for iron content, Fe(II/III) ratio, and for the speciation and fine-grained nature of alteration product minerals that might have important controls on groundwater interaction. Total iron content varies between 0.9% in clays to 5.6% in the andesite. X-ray absorption spectroscopy reveals that Fe in the granitoids and andesite is predominantly Fe(II), and in mudstones, argillaceous limestone and terrestrial sandstone is predominantly Fe(III). The redox reactivity of the potential host rocks both in the presence and absence of Fe(II)-containing 'model' groundwater was investigated using an azo dye as a probe molecule. Reduction rates as determined by reactivity with the azo dye were correlated with the ability of the rocks to uptake Fe(II) from groundwater rather than with initial Fe(II) content. Potential GDF host rocks must be characterized in terms of mineralogy, texture, grain size and bulk geochemistry to assess how they might interact with groundwater. This study highlights the importance of redox reactivity, not just total iron and Fe(II)/(III) ratio, when considering the host rock performance as a barrier material to limit transport of radionuclides from the GDF.

Fracture-fluid relationships: implications for the sealing capacity of clay layers – Insights from field study of the Blue Clay formation, Maltese islands

2014 ◽  
Vol 185 (1) ◽  
pp. 51-63 ◽  
Author(s):  
Yves Missenard ◽  
Audrey Bertrand ◽  
Pierre Vergély ◽  
Antonio Benedicto ◽  
Marc-Edward Cushing ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Co2 Storage ◽  
Complex Deformation ◽  
Potential Host ◽  
Maltese Islands ◽  
Sealing Capacity ◽  
Fracture Fluid ◽  
Clay Layers ◽  
Clay Formation ◽  
Host Rocks

Abstract Sealing capacity of clay layers is a key parameter in many fields of geoscience, such as CO2 storage, hydrocarbons trapping, and waste disposal. In the context of deep geological disposal of radioactive waste, clayey formations are studied as potential host rocks. This work deals with tectonic fracturing, fluid flow, and the sealing capacity of clay layers in an outcropping formation sharing similarities to these potential host rocks. The Blue Clay formation (Maltese islands) outcrops between two limestones affected by slight extensional tectonics. Zones of oxidation around fractures are interpreted as evidence of palaeofluid circulation, and are used to assess the role of joints and faults in controlling the hydrological communication between adjacent layers. Joints and small faults (displacement &lt; 5 m) seem to die out quickly up-section within the Blue Clays, and appear to have played an insignificant role in the palaeohydrology of the area. In contrast, large faults (displacement &gt; 50 m) display clay smear structures, and the lack of oxidized zones around them suggests they served as barriers to fluid flow. Intermediate-sized faults die out up-section into complex deformation zones comprised of irregular joints that are filled with gypsum and surrounded by oxidation zones. These observations indicate that these intermediate-sized faults, usually considered as sealed by classical predictive methods such as “Shale Smear Factor”, may have played a significant role in the local palaeohydrology.

Alteration Mineralogy of the Zhengguang Epithermal Au-Zn Deposit, Northeast China: Interpretation of Shortwave Infrared Analyses During Mineral Exploration and Assessment

2020 ◽  
Author(s):  
Le Wang ◽  
Jeanne B. Percival ◽  
Jeffrey W. Hedenquist ◽  
Keiko Hattori ◽  
Kezhang Qin
Keyword(s):  
Northeast China ◽  
Mineral Exploration ◽  
White Mica ◽  
Absorption Feature ◽  
Hydrous Minerals ◽  
Propylitic Alteration ◽  
Identification Software ◽  
Shortwave Infrared ◽  
Host Rocks ◽  
Epithermal Au

Abstract Alteration mineralogy from shortwave infrared (SWIR) spectroscopy was compared with X-ray diffraction (XRD) analyses for samples from the Zhengguang intermediate sulfidation epithermal Au-Zn deposit, eastern Central Asian orogenic belt, northeast China. The SWIR and XRD analyses indicate that alteration minerals in the vein-adjacent halo mainly comprise quartz, illite, and locally pyrite (QIP) and chlorite, whereas samples from the pervasive propylitic alteration of host basaltic andesite lava contain epidote, chlorite, carbonate, montmorillonite, and locally illite. SWIR mineral identifications from automated mineral identification software may not always be accurate; thus, the results should be validated by the user. The wavelength position of the Al-OH (~2,200 nm; wAlOH) absorption feature can be used to approximate the composition of illite or white mica. However, caution is required when using the wAlOH value to assess paleotemperatures, as the composition of illite can be influenced by the composition of the host rocks or the hydrothermal fluid. In addition, values of the illite spectral maturity (ISM; ratio of the depth of the ~2,200 nm minima divided by the ~1,900 nm minima) can be affected by the presence of other hydrous minerals, quartz-sulfide veins, and absorption intensity (which can be a function of rock coloration). Despite these cautions, the spatial distribution and variation of the wAlOH and ISM values for illite suggest that the high paleotemperature hydrothermal upflow zones related to the Zhengguang Au-Zn deposit were located below ore zones I and IV, which are predicted to be proximal to the intrusive center of the system.

scholarly journals Application of Geochemical Technique in Exploration and Evaluation of Copper, Lead and Zinc Resources of Nepal

1993 ◽  
Vol 9 ◽  
Author(s):  
B. M. Jnawali ◽  
K. M. Amatya
Keyword(s):  
Base Metal ◽  
Host Rock ◽  
Mineral Exploration ◽  
Soil Sampling ◽  
Reliable Estimate ◽  
Soil Geochemistry ◽  
Potential Host ◽  
Lead And Zinc ◽  
Copper Lead

Application of Geochemical technique in mineral exploration was used in Nepal during 1975-1985 by the Mineral Exploration Development Board (MEDR). Systematic drainage reconnaissance over 40,000 km2 area resulted in the recognition of a large number of anomalies several of which are related to previously unknown mineralizations. The anomalies were categorized  into  1  to 4   assessed  on  the  basis  of  magnitude,  homogeneity,  area and potential host rock. All anomalies of category 1 and 2 that were investigated by follow-up stream sediment and soil geochemistry of varying stages were finally found to disclose the mineralized sources. In all cases, detailed grid soil sampling results in conjunction with geologic observations enabled to ascertain the location, extent and continuity of sub­ outcropping bedrock source with considerable precision, but it was not possible to make reliable estimate of grade. It has been attempted to evaluate the base metal resource based on the data available of the MEDR work as well as Department of Mines and Geology (DMG) and others. Although no economic deposits have been discovered except Ganesh Himal Zinc Lead, about 20 base metal prospects have been drilled and tonnage and grade proved and estimated. Of these, Kalitar Copper and Wapsa Copper deposits are considered to be of marginal economic grade, while the rest are inventoried a deposits of subeconomic to non-economic grade.

scholarly journals Mineral Exploration in Mawat Region, Kurdistan-Iraq, Based on Satellite Data and Terrain Prospection

2021 ◽  
Vol 8 (4) ◽  
pp. 249-272
Author(s):  
Marinko Oluić ◽  
Sreten Romandić ◽  
Ratko Vasiljević
Keyword(s):  
Satellite Data ◽  
Mineral Exploration ◽  
Digital Processing ◽  
Field Work ◽  
Measured Concentration ◽  
Copper Mineralization ◽  
Rock Formations ◽  
Lithological Composition ◽  
Color Composite ◽  
Host Rocks

The main goal of the presented exploration was to estimate potential for mineralization in the Mawat ophiolitic massif in Kurdistan, Iraq. The aim of the study was to explore existing copper mineralization and assessor elements gold, platinoids and chromium. Geological exploration detected two types of Cu occurrence a) secondary Cu carbonates (malachite) and b) Cu sulfides (chalcopyrite-pyrite). The Mawat region is mostly built of ultrabasic and basic rocks: peridotites, gabbros, serpentinites and basalts which are heavily deformed, with faults mostly oriented NNW-SSE, and NE-SW. The first phase of exploration comprised digital processing of ASTER and QuickBird satellite images, with appropriate geometrical and radiometric corrections and transformation into coordinate system. Color composite images were produced in different scales. They served to define lithological composition, tectonic settings, location of the points of interest etc. The field work was designed to check satellite data in situ, with focus on perspective rock formations, which might host copper mineralization, and other elements. The host rocks of the ore occurrences are primarily gabbros and metagabbros intersected by diabase dykes, epidote and quartz veins. Secondary mineralization is the product of surficial weathering and it is represented by malachite and limonite. The geophysical survey was very useful in the detection of area with elevated induced polarization and low resistivity. Three perspective areas have been selected for detailed explorations: Waraz, Mirava-Chenara and Konjirin-Kuradawi. The concentration of copper varies highly in very wide ranges; the maximum measured concentration of Cu was determined in Waraz area 6.7%. Some rock samples also show concentration of gold from 0.36 to 2.59 ppm Au. Keywords: Mawat ophiolitic massif, geologic-geophysical explorations, copper mineralization, Kurdistan-Iraq

scholarly journals Exploration Potential of Fine-Fraction Heavy Mineral Concentrates from Till Using Automated Mineralogy: A Case Study from the Izok Lake Cu–Zn–Pb–Ag VMS Deposit, Nunavut, Canada

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 310 ◽  
Author(s):  
H. Donald Lougheed ◽  
M. Beth McClenaghan ◽  
Dan Layton-Matthews ◽  
Matthew Leybourne
Keyword(s):  
Mineral Exploration ◽  
Fine Fraction ◽  
Test Site ◽  
Massive Sulfide ◽  
Heavy Mineral ◽  
Morphological Data ◽  
Indicator Mineral ◽  
Automated Mineralogy ◽  
Sediment Cover ◽  
Liberation Analysis

Exploration under thick glacial sediment cover is an important facet of modern mineral exploration in Canada and northern Europe. Till heavy mineral concentrate (HMC) indicator mineral methods are well established in exploration for diamonds, gold, and base metals in glaciated terrain. Traditional methods rely on visual examination of >250 µm HMC material, however this study applies modern automated mineralogical methods (mineral liberation analysis (MLA)) to investigate the finer (<250 µm) fraction of till HMC. Automated mineralogy of finer material allows for rapid collection of precise compositional and morphological data from a large number (10,000–100,000) of heavy mineral grains in a single sample. The Izok Lake volcanogenic massive sulfide (VMS) deposit, one of the largest undeveloped Zn–Cu resources in North America, has a well-documented fan-shaped indicator mineral dispersal train and was used as a test site for this study. Axinite, a VMS indicator mineral difficult to identify optically in HMC, is identified in till samples up to 8 km down ice. Epidote and Fe-oxide minerals are identified, with concentrations peaking proximal to mineralization. Corundum and gahnite are intergrown in till samples immediately down ice of mineralization. Till samples also contain chalcopyrite and galena up to 8 km down ice of mineralization, an increase from 1.3 km for sulfide minerals in till previously reported for coarse HMC fractions. Some of these sulfide grains occur as inclusions within chemically and physically robust mineral grains and would not be identified visually in the coarse HMC visual counts. Best practices for epoxy mineral grain mounting and abundance reporting are presented along with the automated mineralogy of till samples down ice of the deposit.

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