Major and minor element lithogeochemical anomalies surrounding the Louvem copper deposit, Val d'Or, Quebec

1978 ◽  
Vol 15 (7) ◽  
pp. 1161-1169 ◽  
Author(s):  
Guy Spitz ◽  
Richard Darling

Major element distributions in meta-rhyodacitic flows and fragmental rocks surrounding the Louvem volcanogenic copper deposit show a broad linear anomaly parallel to the local strike. At least 420 m long and up to 210 m wide, this altered area contains rocks that have high Fe+2, S, and low Na2O, CaO, and CO2 values. Included in the central portion of this large anomaly is a 100 m by 50 m highly altered area that contains rocks with high H2O and MgO values and crudely outlines the ore deposit.Element-ratio maps and a map showing percentage peraluminous character all display easily recognizable anomalies that mark the zone of altered rocks enclosing the ore deposit. Of the element ratios investigated at Louvem, Al2O3/Na2O appears to offer the most practical tool for mineral exploration.The chemical zoning of the altered fragmental layer that includes the copper ore is symmetrical about the long axis of the stratigraphically concordant orebody, but in a longitudinal direction this symmetry is absent. Instead, the alteration changes progressively from dominantly chloritic at the western end to pyritic at the eastern end of the study area. This alteration pattern seems to suggest that ore deposition was effected by hydrothermal solutions moving along the layer of now-altered fragmental rocks. By analogy with the chloritic alteration pipes underlying pyritic volcanogenic deposits, it seems probable that the direction of fluid flow was from west to east.

1982 ◽  
Vol 48 (1) ◽  
pp. 459-465 ◽  
Author(s):  
R. F. Tylecote ◽  
P. T. Craddock

Jovanovič has recently drawn attention to the early copper mine at Rudna Glava in the copper mining area of Maidanpek-Bor in Eastern Serbia (Jovanovič 1979, 103). This copper deposit has iron associated with it. In some respects this occurrence of iron and copper together compares with the deposit at Phalabora in South Africa where copper and other minerals are mined today. Rudna Glava has been a copper mine in the Chalcolithic period and an iron mine in the Turkish period. Today it is worked out, but the working of the iron ore has left exposed some of the shafts and galleries used by Chalcolithic and Bronze Age copper miners. It has been possible to obtain a sample of the copper ores used in the early periods and integrate them into a smelting programme (Tylecote et al. 1977, 305), the main purpose of which has been to determine the partitioning of the three elements between the ore, the slag and the metal. The object of this exercise was to try and relate the artefacts, the slag, and metal to the ore source. So far, ores from the British Isles, Spain, and Africa have been examined and reported (Tylecote 1977). The sample from Yugoslavia came rather too late for the first report but the work is continuing.The smelting work described in this report was carried out by Ali Ghaznavi and the analyses were kindly made by R. Hetherington formerly of Newcastle University and Dr P. T. Craddock of the British Museum Research Laboratory. I have to thank Dr B. Jovanovič of the Archaeological Institute, Belgrade, for supplying the material and inspiring the work.


Kakosa South copper deposit is located about 450km northwest of Lusaka between Chingola and Chililabombwe. A comprehensive study of Kakosa South deposit was carried out. In Kakosa area the footwall aquifer rocks comprising sandstone and conglomerates which are thin and as such are not expected to represent major aquifers. Copper mineralisation is found in the upper quartzite and ore-shale. The inclination of the deposit ranges from 250 up to 350 . The hangingwall formations above the upper quartzite are represented by a sequence of dolomite and shale formations. Based on Kakosa geotechnical analysis and rock mass classification, fuzzy TOPSIS approach was employed for the selection of optimal extraction techniques. FTOPSIS approach has precise and specific quantities which are used in order to establish criteria and option weights. Triangular fuzzy numbers were determined to represent semantic variables. The fuzzy numbers for Kakosa South parameters were used as input data in the decision making model and matched against the criteria required for the mining method. Applying FDM model, extraction techniques were ranked. The results indicated that open pit extraction technique was ranked first with 78.90 scores followed by sublevel stoping with 66.88 scores. It is concluded that the Kakosa South copper ore deposit can optimally be extracted by open pit mining up to transition depth and transit from open pit mining to underground mining employing sublevel stoping.


2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Paweł KURZYDŁO ◽  
Witold PAWLOS

The Zechstein copper ore deposit located on the Foresudetic monocline has a complex geological structure both in lithological and mineralogical aspects. The significant variability in quantity and quality of minerals deposited in the ore bed is one of the factors determining the susceptibility of copper ore to beneficiation based on flotation, which is carried out in the KGHM Concentration Plant. Based on the algorithm developed, flotation experiments on a laboratory scale have been conducted to predict the upgrade rates under industrial conditions. This paper provides the results of the mineralogical examination of the flotation products performed by one of the KGHM Concentration process lines and compares the beneficiation of various copper sulphide minerals. The results of the laboratory tests have been compared with the results of sampling carried out simultaneously at the process line. A procedure has been proposed to develop equations defining the industrial upgradability curves for copper sulphide minerals under the KGHM Concentration Plant conditions.


2018 ◽  
Vol 66 ◽  
pp. 01010
Author(s):  
Anna Barbara Gogolewska ◽  
Natalia Czajkowska

The copper ore deposit situated in the south-west of Poland is mined by three underground mines owned by KGHM Polish Copper JSC. Exploitation has been accompanied by rock burst hazard since the beginning. Thus, numerous different preventing measures have been developed such as temporary, organizational and long-term ones. However, no one has been able to predict the time, place and energy of a seismic event. The group winning blasting, with maximum number of blasted faces, is the most effective operation to reduce seismic threat. The more faces are blasted the more seismic energy should be reduced. The study aims at assessing the blasting effectiveness in inducing rock bursts and tremors. For this purpose, the seismic activity induced by mining and blasting were investigated. The number of blasting works and blasted faces as well as length of time between subsequent blasting works were analysed and related to provocation effectiveness. The linear correlation and different regressions were calculated to determine these relations. Moreover, the seismic energy reduction in the rock mass was evaluated by means of SRMS Index, which is a factor measured directly before and after blasting. The analyses covered one mine panel in the Polkowice-Sieroszowice copper mine over four-year period.


2020 ◽  
Vol 115 (2) ◽  
pp. 231-239 ◽  
Author(s):  
Jeffrey W. Hedenquist ◽  
Yasushi Watanabe ◽  
Antonio Arribas

Abstract Surface samples of hypogene alunite that cement late breccia bodies from the El Salvador porphyry copper district of Chile were recently dated. One alunite sample over the principal Turquoise Gulch porphyry deposit has a 40Ar/39Ar total gas age of 40.64 ± 1.04 Ma, overlapping the age of a late latite intrusion. Two other samples associated with quartz-alunite replacement of rhyolite, ~750 m southwest of the collapse zone over the block cave of the porphyry copper deposit, are distinctly younger, at 38.12 ± 0.66 and 38.04 ± 0.22 Ma (averages of duplicate analyses, with ±2σ errors). Previously reported U/Pb ages of zircons from 15 Eocene-age diorite, granodiorite, and granite porphyry intrusions have weighted mean ages that range from about 44 to 41 Ma, with peak magmatic flux interpreted at 44 to 43 Ma. Porphyry copper ores in the El Salvador district formed at about the same time as porphyry intrusions, with intrusive centers that migrated in a south-southwest direction, from the small deposits at Cerro Pelado (~44.2 Ma), to Old Camp (~43.6 Ma) and M Gulch-Copper Hill (~43.5–43.1 Ma), to the main ore deposit at Turquoise Gulch (~42 Ma). The granodiorite porphyry intrusions at Turquoise Gulch are associated with ~80% of the known copper ore of the district; they record waning stages of magmatism at 42.5 to 42.0 Ma, followed by weakly altered latite dikes at 41.6 Ma. Molybdenite in quartz veins returned Re-Os ages of 41.8 to 41.2 Ma. The two alunite samples from our study with coincident dates of ~38 Ma provide evidence for magmatic-hydrothermal activity younger than any recognized to date, consistent with the alteration overprint of quartz-alunite on older muscovite after erosion. This younger activity must have been associated with a blind intrusion, likely located south of the Turquoise Gulch deposit, based on the distribution of alteration minerals, and offset from the zoning associated with the Turquoise Gulch center. Stable isotope values (δ34S, δ18O, δD) of the ~38 Ma alunite indicate a high-temperature hypogene origin, consistent with formation in a lithocap environment that typically is located at shallow levels over and on the shoulders of porphyry copper deposits. Both observations—alteration overprint and markedly younger age of alunite—indicate the potential for porphyry copper mineralization south of Granite Gulch, as much as 1,000 m below the level of the coeval outcropping quartz-alunite replacement, perhaps near ~2,000-m elevation; this is hundreds of meters deeper than the known copper ore of Turquoise Gulch.


1973 ◽  
Vol 39 (301) ◽  
pp. 58-64 ◽  
Author(s):  
F. C. W. Dodge

SummaryOccurrence and major- and minor-element compositions of chlorites from plutonic rocks of the central Sierra Nevada batholith have been studied in detail.Chlorite has formed largely as an alteration product of biotite, presumably late in the magmatie history of the granitic rocks as a result of subsolidus reaction. Major-element composition of chlorite is strongly influenced by composition of coexisting biotite. Minor-element differences between the two minerals can, for the most part, be attributed to structural differences. The minor-element data, particularly for Cu, indicate that the process of chloritization is not a likely mechanism for release of ore metals from primary minerals.


2021 ◽  
Vol 29 (2) ◽  
pp. 189-196
Author(s):  
Martin Števko ◽  
Jiří Sejkora ◽  
Zdeněk Dolníček

An interesting occurrence of olivenite and cornwallite was recently discovered in cavities of quartz at the Podlipa copper deposit near Ľubietová, Slovakia. Olivenite occurs as olive to pale green sprays or radial aggregates consisting of individual acicular crystals up to 5 mm long. Its refined unit-cell parameters (for the monoclinic space group P21/n) are: a 8.6192(13) Å, b 8.2300(11) Å, c 5.9349(8) Å, α 90.055(12)° and V 420.99(7) Å3. Studied olivenite shows intense chemical zoning caused by strong variation of As and P contents. Most of the zones are corresponding to olivenite (with P content ranging between 0.02 to 0.39 apfu), but darker zones or domains of As-rich libethenite (with As content ranging between 0.18 to 0.24 apfu) were occasionally observed. Cornwallite forms dark green massive fillings between olivenite crystals or microcrystalline botryoidal crusts. The refined unit-cell parameters (for the monoclinic space group P21/c) of botryoidal cornwallite from the Podlipa deposit are: a 4.6112(2) Å, b 5.7698(3) Å, c 17.4167(11) Å, β 92.009(5)° and V 463.10(3) Å3. The two compositional types of cornwallite were distinguished. The first type is represented by relatively homogenous aggregates with only minor contents of P (from 0.04 to 0.22 apfu). The second type occurs as polycrystalline fillings with strong chemical zoning and has much more significant variation of As and P contents, representing solid-solution series between P-rich cornwallite (with 1.41 apfu of As and 0.59 apfu of P) and As-rich pseudomalachite (with 1.37 apfu of P and 0.63 apfu of As).


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