Ore Mineralogy of the Louvem Copper Deposit Val d'Or, Quebec

1972 ◽  
Vol 9 (12) ◽  
pp. 1596-1611 ◽  
Author(s):  
Jayanta Guha ◽  
Richard Darling
Keyword(s):  
Copper Deposit ◽  
Wall Rock ◽  
Textural Features ◽  
Ore Deposit ◽  
Ore Body ◽  
Ore Minerals ◽  
Wall Rock Alteration ◽  
Ore Mineralogy ◽  
Rock Alteration ◽  
Host Rocks

Microscopic study of samples from the Louvem copper deposit shows that the principal ore minerals are pyrite, chalcopyrite, and sphalerite and the accessory ore minerals are rutile, tetradymite, two unidentified tellurides, cobaltite, molybdenite, galena, and four optically distinct phases having compositions along the digenite–bornite tie line.The Louvem ore body is a pipe-shaped mass of mineralized rhyolitic tuff and agglomerate that is conformable with enclosing volcanic and pyroclastic rocks. The ore body is zoned, with a copper-rich core and pyrite-rich margins. Wall-rock alteration spatially related to the ore deposit suggests that it was formed by replacement of porous tuffaceous host rocks by a hydrothermal fluid. Textural features of the ore indicate that it was subjected to post-emplacement thermal metamorphism.

Reactions between uranium veins and their host rocks in Vendée and Limousin (France)

1981 ◽  
Vol 44 (336) ◽  
pp. 417-423 ◽  
Author(s):  
M. Cathelineau ◽  
J. Leroy
Keyword(s):  
Structural Characteristics ◽  
Wall Rock ◽  
Structural Features ◽  
Gangue Mineral ◽  
List Type ◽  
Vein Formation ◽  
Wall Rock Alteration ◽  
Rock Alteration ◽  
Host Rocks ◽  
Basic Rocks

AbstractHydrothermal uranium veins, associated with the Hercynian leucogranites show important variations in their mineralogical, chemical and structural features in relation to the host rock lithology. These are described with particular reference to the Chardon deposit, Vendée where the veins cut granite, basic lithologies, and shales. The following features are described: 1Changes in the thickness of veins near to contact zones, particularly those between granites and basic lithologies, lamprophyres, and shales.2Changes in the gangue mineral assemblage with the preferential development of carbonate in veins cutting basic lithologies, and of silica in veins which cut granite.3Paragenetic zoning in the veins in passing from granites to their metamorphic aureoles.Comparisons between deposits of Vendée, Limousin, and Erzgebirge allow the following generalizations to be made: 1Open faults and subsequent mineralization are concentrated at boundaries between competent and more plastic lithologies.2Mineralizing fluids cause wall-rock alteration characterized by the removal of Si from granite and of Ca, Mg, Fe from metamorphic and basic rocks.3The chemical and structural characteristics of wallrocks are important controls on the mineralization but in acid lithologies the main controls on the pitchblende vein formation are the structural characteristics of the wallrock.

Geological Characteristics and Prospecting Criteria of Sanbao Silver Polymetallic Ore Deposit in Malipo Cuntry of Yunnan Province

2013 ◽  
Vol 868 ◽  
pp. 88-91
Author(s):  
Jian She Wang ◽  
Yong Feng Yan ◽  
Dong Wang ◽  
Peng Yu Feng
Keyword(s):  
Low Temperature ◽  
Yunnan Province ◽  
Wall Rock ◽  
Ore Genesis ◽  
Ore Deposit ◽  
Geological Characteristics ◽  
Polymetallic Deposit ◽  
Wall Rock Alteration ◽  
Rock Alteration ◽  
Polymetallic Ore

Sanbao silver polymetallic deposit is overally located in the front of "North convex" in Laojun Mountain granite body, belonging to polymetallic deposit of stratabounded medium-low temperature hydrothermal reformation genesis. It has been found that six mineralized belt, having developed the wall-rock alteration. The prospecting criterion is determined by ore genesis and ore-controlling factor.

scholarly journals The Buenaventura Sector of the San Finx W–Sn Deposit (NW Spain): Ore Mineralogy, Host Rocks and Associated Hydrothermal Alteration

2021 ◽  
Vol 6 (1) ◽  
pp. 11
Author(s):  
David Garófano-Medina ◽  
Mercedes Fuertes-Fuente ◽  
Antonia Cepedal ◽  
Agustín Martin-Izard
Keyword(s):  
Hydrothermal Alteration ◽  
Nw Spain ◽  
Ore Deposit ◽  
Main Host ◽  
Ore Minerals ◽  
Ore Mineralogy ◽  
Native Bismuth ◽  
Host Rocks ◽  
Spanish Province

The San Finx W–Sn ore deposit is located in the Spanish province of A Coruña (Galicia, NW Spain). Geologically, it occurs in the Galicia-Trás-os-Montes zone which is one of the innermost zones of the Iberian Variscan collisional belt. This ore deposit is characterized by NE–SW trending quartz-dominated veins with centimeter-size hübnerite and cassiterite. This research focuses on one sector of this deposit known as Buenaventura. The aim of this work is to present a mineralogical and petrological characterization of the ore-bearing veins, their host rocks and associated hydrothermal alteration. The vein mineralogy is mainly quartz, muscovite, K-feldspar, apatite and scarce fluorite. The ore minerals are hübnerite, scheelite and cassiterite with columbite and ilmenorutile-struverite inclusions, together with sulfides, mainly chalcopyrite and arsenopyrite, and, in less abundance, molybdenite, löllingite, pyrrhotite, sphalerite, stannite, pyrite, Bi-Pb-Ag sulfosalts and native bismuth. The main host-rocks are micaschist and paragneiss and two types of pegmatites, homogeneous pegmatites and banded aplite-pegmatites with columbite. The host rocks are affected by four types of hydrothermal alterations: tourmalinization, greissenization, feldspathization and silicification. The more widespread alteration is the feldspathization in which the protolith is replaced by massive albite and K-feldspar with fibrous habit, accompanied by apatite, chlorite, rutile, magnetite, hematite, chalcopyrite and sphalerite. In addition, there are highly deformed areas with a complex alteration rich in K-feldspar and sulfides, mainly chalcopyrite, minerals of the stannite group and sphalerite and, in less abundance, bismuthinite, native bismuth, galena and pyrite. This deposit shares features in terms of geological setting, hydrothermal alteration and ore assemblages with exogreisen systems formed in the cupolas of highly fractionated granites in collisional settings.

scholarly journals Spectral Alteration Zonation Based on Close Range HySpex-320 m Imaging Spectroscopy: A Case Study in the Gongchangling High-Grade Iron Ore Deposit, Liaoning Province, NE China

2020 ◽  
Vol 10 (23) ◽  
pp. 8369
Author(s):  
Kun Song ◽  
Ende Wang ◽  
Yuzeng Yao ◽  
Jianfei Fu ◽  
Dahai Hao ◽  
...  
Keyword(s):  
Iron Ore ◽  
Spectral Characteristics ◽  
Wall Rock ◽  
Iron Deposit ◽  
Spectral Features ◽  
High Grade ◽  
Rock Interaction ◽  
Ore Body ◽  
Wall Rock Alteration ◽  
Rock Alteration

Research on wall rock alteration is of great importance to the understanding and exploration of ore deposits. The microscopic changes of the same mineral in different alteration zones can provide information about the migration and enrichment of ore-forming elements. In this paper, a typical profile of a high-grade iron ore body in Gongchangling iron deposit was investigated and sampled. The samples were checked by polarized microscopy, and alterations zonation were delineated according to the hydrothermal mineral assemblages and paragenesis. Moreover, hyperspectral images of wall rocks from each alteration zone were obtained by Norsk Elektro Optikk (NEO) HySpex-320 m imaging system. A customer Interactive Data Language (IDL) software package was used to process the images, and spectral features were extracted from the selected samples. The results indicate that spectral characteristics manifest obviously regular variations; i.e., from proximal to distal for the high-grade iron ore body, the wavelengths at ca. 1200 nm of chlorite and garnet, which accounts for most of the hydrothermal alteration minerals, become longer, and the absorption depths gradually smaller. The spectral features at 1200 nm of chlorite and garnet are always caused by the crystal field effect of Fe2+; therefore, the wavelength variations indicate the increase of Fe2+ and a reduced environment, which can provide more detailed information about the metallogeny and water–rock interaction. Since the hyperspectral features of the altered rocks can disclose unique mineralogical and structural information, the conventional classification of alteration zonation should be combined with the spectral feature, i.e., spectral alteration zonation, which is of great help to the understanding of the forming conditions of wall rock alteration and also the high-grade iron ore bodies.

The Touquoy Zone deposit: an example of "unusual" orogenic gold mineralisation in the Meguma Terrane, Nova Scotia, Canada

2003 ◽  
Vol 40 (3) ◽  
pp. 447-466 ◽  
Author(s):  
Frank P Bierlein ◽  
Paul K Smith
Keyword(s):  
Close Correlation ◽  
Wall Rock ◽  
Convincing Evidence ◽  
Structural Level ◽  
Vein Formation ◽  
Wall Rock Alteration ◽  
Base Metal Sulphides ◽  
Meguma Terrane ◽  
Rock Alteration ◽  
Host Rocks

The Touquoy Zone deposit is host to disseminated gold mineralisation in metasiltstones of lower Palaeozoic age. From the close correlation between ore grades and the intersection of favourable stratigraphy and bounding faults, it is apparent that mineralisation is controlled by both structural and lithological influences. Within the ore zone, disseminated gold, arsenopyrite, pyrite, and rare base-metal sulphides are associated with a network of widely spaced, millimetre-scale, quartz–carbonate veinlets. Quasi-pervasive fluid flow and prolonged interaction with the host rocks resulted in a diffuse, but pronounced halo of wall-rock alteration that is characterized by the breakdown of detrital feldspar and metamorphic chlorite and the development of hydrothermal carbonate phases, K-mica, and disseminated sulphides. These mineralogical changes are accompanied by enrichment in CO2, K, Au, As, and S and depletion in Na across the ore zone. Vein formation occurred at between 250° and 350°C and pressures of less than 1–2 kbar (1 kbar = 100 MPa), corresponding to an estimated depth of between <2.8 and 6 km. Mineralisation resulted from the unmixing of an overpressured (low-salinity, CO2-rich) fluid in response to decreasing pressure during its ascent and penetration into permeable host rocks. Geological and geochemical features of mineralisation in the Touquoy Zone deposit are seen as convincing evidence for a close genetic association between disseminated-style and lode gold mineralisation in orogenic terrains, with the resulting style of mineralisation largely controlled by the overall structural geometry of the mineralising site, rheological properties, permeability and chemical receptiveness of the host rock, and structural level of emplacement.

Pétrographie des Roches Encaissantes du Gisement Cuprifère de Louvem

1973 ◽  
Vol 10 (5) ◽  
pp. 760-776 ◽  
Author(s):  
Guy Spitz ◽  
Richard Darling
Keyword(s):  
Volcanic Rocks ◽  
Volcanic Belt ◽  
Copper Deposit ◽  
Wall Rock ◽  
Structural Features ◽  
Alteration Zone ◽  
Pyroclastic Rocks ◽  
Wall Rock Alteration ◽  
Host Rocks ◽  
Metamorphic Facies

The Louvem copper deposit, discovered by SOQUEM in 1968, is situated in the Precambrian volcanic belt that stretches between the mining districts of Noranda and Val d'Or. The ore deposit is in the upper part of the volcanic pile, near the base of the overlying silicic pyroclastic rocks, and it is conformable with surrounding rocks. Its host rocks are meta-rhyodacite and meta-dacite flows and silicic pyroclastic rocks including tuff, agglomerate, and breccia. The principal structural features are a well-developed shear zone along the original footwall of the deposit and a locally-developed, complexly folded zone that perhaps represents a zone of slumping along the original roof of the deposit. The rocks surrounding the deposit contain mineral assemblages characteristic of the greenschist metamorphic facies. Wall-rock alteration surrounding the deposit includes pyritization, chloritization, sericitization, and silicification. Pyrite and chlorite alteration is characteristic of rocks immediately surrounding the ore while sericite and secondary quartz are present in an outer alteration zone further from the deposit. Ore deposition took place in a zone of permeable pyroclastic rocks sandwiched between two massive bands of volcanic rocks.

Characteristics of Lead and Zinc Polymetallic Deposit and Wall Rock Alteration Zoning in Luziyuan, Yunnan

2013 ◽  
Vol 734-737 ◽  
pp. 52-55
Author(s):  
Lei Zeng ◽  
Ming Guo Deng ◽  
Chang Liang Lv ◽  
Wei Liu
Keyword(s):  
Wall Rock ◽  
Geological Investigation ◽  
Polymetallic Deposit ◽  
Ore Body ◽  
Lead And Zinc ◽  
Alteration Zoning ◽  
Ore Mineralization ◽  
Wall Rock Alteration ◽  
Lead Zinc ◽  
Rock Alteration

The lead and zinc polymetallic deposit in LuziYuan is an ultra-large type skarn deposit. The ore body originated from the interlayer crushed zone between the second and thrid section of stratum marble and slate (schist) interbedding of upper Cambrian series Shahechang group, the wall rock alteration is intensice in the diggings, and the alteration zoning is obvious. Through field geological investigation and data analysis, based on the petrography of alterated rocks and combined with catalog information of drilling, the wall rock alteration in the diggings of LuziYuan is divided into four alteration zones,which are in sequence: carbonate-quartz-chloritization zone; carbonate-quartz-skarn lithification zone; skarn-lead zinc ore mineralization zone; and skarn-pyritization zone. The forming of ore body is related to alterations such as skarn lithification, silicification, marmarization, magnetite, etc.

scholarly journals STUDY OF THE WALL ROCK ALTERATION OCCURRING IN ULTRAM A F I C ROCKS HOSTING MAGNESITE DEPOSITS, EVIA, GREECE,

2004 ◽  
Vol 36 (1) ◽  
pp. 377 ◽  
Author(s):  
Κ. Σερέλης ◽  
Ε. Γκάρτζος ◽  
Π. Τσαουσίδου
Keyword(s):  
Wall Rock ◽  
Open Pit ◽  
Medium Size ◽  
Type B ◽  
Open Pit Mines ◽  
Argillic Alteration ◽  
Wall Rock Alteration ◽  
Alteration Processes ◽  
Rock Alteration ◽  
Host Rocks

Three different kinds of alteration processes occur in the studied ultramafic host rocks of the magnesite deposits of N. Evia. In chronological order: Pre-magnesite event (serpentinization), syngenetic brown alteration and weathering. This paper concerns the syngenetic wall rock alteration of the ultramafic host rocks. Two types of wall rock alteration were distinguished. The first one named type (B-i) concerns cases of brown alteration accompanying thin to medium size veins of magnesite. Alteration is restricted in thin (a few cm to 20 cm) vein-parallel bands occurring on both sides of the vein. Alteration increases gradually towards the edges of the vein. The altered band consists mainly of abundant dolomite and/or quartz. The second type (B2) concerns argillic alteration of large ultramafic masses in areas with intense magnesite mineralization and can be observed along the walls of the open pit mines. Secondary vermiculite has been formed in this case. Both types are related to the genesis of the magnesite deposits

Sign in / Sign up

Export Citation Format

Share Document