To see the other types of publications on this topic, follow the link: Volcanogenic massive sulfide.
Dissertations / Theses on the topic 'Volcanogenic massive sulfide'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 16 dissertations / theses for your research on the topic 'Volcanogenic massive sulfide.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Hettula, J. (Jesse). "Pyhäsalmi volcanogenic massive sulfide deposit, central Finland." Bachelor's thesis, University of Oulu, 2017. http://urn.fi/URN:NBN:fi:oulu-201710253010.
Full textAbstract:
Pyhäsalmi mine is located in central Finland, at the eastern side of the Pyhäjärvi lake. The Pyhäsalmi deposit is polymetallic Zn-Cu VMS ore body with total reserve, mined and yet to be mined, of 58.3 Mt @ Cu 0.9 %, Zn 2.4 %, S 37.8 %, Au 0.4 g/t and Ag 14 g/t. At the end of 2013, 51 Mt of ore has been mined. The mine will be in operation until August of 2019.
The Pyhäsalmi deposit is hosted in a felsic-dominated bimodal Proterozoic succession. Local hydrothermal alteration is composed of sericite-quartz alteration, and intensifies when it is in close proximity with the upper ore body. The deep ore body is thrusted into unaltered metamorphosed hangingwall volcanic rock, thus separated from the alteration zone.
The Pyhäsalmi district and deposit has been subjected to four different tectonic phases (D1–D4) and intrusions accompanied by them. These tectonic processes have thrusted the deposit in upright position from the original position.
Basic theory of VMS formation processes can be used for modeling Pyhäsalmi deposit formation process, which in turn can benefit massive sulfide exploration.
2
Miranda, Gasca Miguel Angel. "The volcanogenic massive sulfide and sedimentary exhalative deposits of the Guerrero Terrane, Mexico." Diss., The University of Arizona, 1995. http://hdl.handle.net/10150/187087.
Full textAbstract:
More than 60 volcanogenic massive sulfide and sedimentary exhalative deposits are located in the composite upper Jurassic-lower Cretaceous Guerrero terrane of western Mexico. The deposits range from less than 100,000 metric tons up to 6 million metric tons. Most of the deposits are Zn-Pb-Cu Kuroko type and are located within the Zihuatanejo and Teloloapan subterranes. The Guanajuato and Calmalli, Baja California, deposits are Zn-Cu. The Cu type Copper King, Guerrero, deposit is located in the Papanoa complex. Arroyo Seco, Michoacan, is the only Pb-type and can be classified as a sedimentary-exhalative deposit. The sulfides lenses have suffered metamorphism. The δ³⁴S values of Teloloapan deposits are mainly negative. The mean δ³⁴S values of the deposits of Zihuatanejo subterrane are mainly positive. Lead isotopic data suggest that the source of metals for the Zihuatanejo, Teloloapan and Huetamo Tertiary epigenetic deposits of the Guerrero terrane was a combination of metal sources e.g. the Mesozoic crust, the middle-Tertiary volcanic rocks, and the Sierra Madre Oriental. Guanajuato, Zacatecas, Fresnillo, and Real de Angeles districts are located at the suture zone between Guerrero terrane and Sierra Madre Oriental that could have provided channels for hydrothermal systems that extracted metals from different sources.
3
Lalonde, Erik. "Alteration and Cu-Zn mineralization of the turgeon volcanogenic massive sulfide deposit (New Brunswick, Canada)." Thesis, Université Laval, 2014. http://www.theses.ulaval.ca/2014/30505/30505.pdf.
Full textAbstract:
Le gîte Turgeon est un sulfure massif volcanogène (SMV) riche en Cu-Zn, encaissé dans les roches volcano-sédimentaires ordoviciennes du Groupe de Fournier dans la Boutonnière Elmtree-Belledune, au Nouveau-Brunswick (Canada). Le Groupe de Fournier comprend les formations Devereaux et Pointe Verte, qui sont tous les deux composées de gabbros et de basaltes cousinés. Le gîte Turgeon est composé de deux lentilles de sulfures massifs Cu-Zn avec des stockwerks chalcopyrite-pyrite sous-jacents aux deux lentilles. La géochimie indique que les roches encaissantes sont des basaltes et des andésites d’affinité tholéiitique de type MORB. Les roches encaissantes proximales aux lentilles de sulfures massifs sont composées de chlorite + quartz dans les zones stockwerks, tandis que les zones adjacentes aux lentilles de sulfures massifs sont altérées en calcite + sidérite + pyrite + talc. Les sulfures à Turgeon ont une valeur δ34S moyenne de 6.9 ‰ (5.8 – 10‰), indiquant que le soufre est principalement dérivé de la réduction thermochimique de sulfate d’eau de mer ordovicienne.The Turgeon deposit is a mafic-type Cu-Zn volcanogenic massive sulfide (VMS) deposit hosted in the Middle Ordovician gabbros, sheeted dykes, and pillow basalts of the Devereaux Formation of the Fournier Group in the Elmtree-Belledune Inlier, northern New Brunswick (Canada). The Turgeon deposit consists of two lensed-shaped Cu-Zn massive sulfide zones (“100m Zinc”, “48-49”) composed of pyrite, chalcopyrite, pyrrhotite, and sphalerite, underlain by chalcopyrite-pyrite stockworks. Trace element geochemistry indicates that the host rocks are composed primarily of tholeiitic basalts and andesites with mid-ocean ridge basalt (MORB) signatures. Alteration mineral assemblages of the footwall basalts proximal to mineralization are dominantly chlorite ± quartz in the stockwork zone, and calcite ± siderite ± pyrite ± talc near the massive sulfide lenses. Sulfides at Turgeon have an average δ34S of 6.9 ‰ (5.8 – 10‰), indicating that sulfur was derived from thermochemical reduction of Ordovician seawater sulfate.
4
van, Hees Gregory W. H. "Chemostratigraphy and Alteration Geochemistry of the Lundberg and Engine House Volcanogenic Massive Sulfide Mineralization, Buchans, Central Newfoundland." Thesis, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20659.
Full textAbstract:
The world-class Buchans Mining Camp hosts a number of high-grade, low-tonnage volcanogenic massive sulfide (VMS) deposits. The Lundberg and Engine House zones form the lower-grade stockwork to the Lucky Strike deposit and have yet to be mined. A detailed study of the Lundberg and Engine House zones was conducted to establish the stratigraphic setting of the deposits, to determine the petrology of the host volcanic rocks and distribution of alteration facies, and to characterize the mineralization with the goal of improving exploration for polymetallic massive sulfide deposits in the Buchans camp.
5
Ruks, Tyler William. "Stratigraphic and paleotectonic studies of Paleozoic Wrangellia and its contained volcanogenic massive sulfide (VMS) occurrences, Vancouver Island, British Columbia, Canada." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54599.
Full textAbstract:
Wrangellia is a fundamental component of the North American Cordillera and contains significant mineral deposits, including Myra Falls (Nyrstar N.V.), which is currently the largest producing volcanogenic massive sulfide (VMS) deposit in western Canada. Understanding the evolution of Wrangellia is therefore important for understanding the crustal growth and metallogenic history of the North American continent, and in doing so, facilitating the discovery of new mineral wealth. Geochronological, lithogeochemical and Nd and Pb isotopic studies of the Paleozoic Wrangellia arc (PWA), Vancouver Island have significantly revised our understanding of the terrane, suggesting that the PWA comprises a progressively rifting Late Devonian through Early Permian oceanic volcanic arc complex developed above an east dipping subduction zone (modern coordinates) with Late Devonian through middle Mississippian, and Pennsylvanian through Early Permian pulses of bimodal volcanism and associated VMS mineralization. The relatively primitive lithogeochemical and Nd isotopic signatures of PWA intrusive and volcanic rocks indicate that the PWA originated in an oceanic arc environment close enough to a continental margin to undergo slight contamination via the subduction of continent derived sediments. Recently recognized, Pennsylvanian-Early Permian aged, VMS associated bimodal volcanic rocks in the PWA have lithogeochemical and Nd isotopic signatures indicative of derivation from more primitive and significantly hotter source melts than their Late Devonian counterparts, suggesting that Late Paleozoic volcanic rocks in the terrane are prospective for VMS mineralization. Lead isotope geochemistry of newly discovered VMS style mineralization in the PWA indicates that host areas for the new mineral occurrences are prospective for Myra Falls-like VMS deposits of Late Devonian-Early Mississippian age. Lead isotope geochemistry for recently recognized Pennsylvanian-Early Permian VMS mineralization in the PWA supports lithogeochemical and Nd isotopic arguments which suggest that Late Paleozoic bimodal volcanic rocks in the PWA were derived from more primitive melts than their Late Devonian-Early Mississippian counterparts, reflective of an origin in a progressively rifting, oceanic island arc environment.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
6
Gemmell, Thomas P. "Geology of the Kidd Creek Deep Orebodies - Mine D, Western Abitibi Subprovince, Canada." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26116.
Full textAbstract:
The giant Kidd Creek Mine is an Archean Cu-Zn-Ag deposit in the Abitibi Greenstone belt, located in the Superior Province of Canada and is one of the largest known base metal massive sulfide mines in the world with a tonnage of 170.7 Mt (Past production, Resource and Reserve). The massive sulfides in Mine D comprise a number of ore lenses that are interpreted to be the downplunge continuation of the Central orebody from the upper mine. These are referred to as the West, Main, and South lenses. The massive sulfides overlie a silicified rhyolitic unit at the top of a mixed assemblage of rhyolite flows, volcaniclastic sediments and ultramafic flows. The sheared nature of the fragmental units in the hanging wall of the deposit, at depth, illustrates the greater deformation that has occurred than in the upper mine. Metal zonation and the distribution of Cu stringer mineralization suggest that the West and Main lenses may be part of a single massive sulfide body (Main orebody) that has been structurally dismembered. The South Lens is a detached body, separated by late faults. The large Cu stringer zone beneath the West and Main lenses has a thickness of up to 150 metres, and is much broader and structurally remobilized in Mine D partially due to a newly identified series of vertically trending offset faults, that extends along the entire length of the massive sulfide bodies. A number of features of the North, Central and South orebodies in the upper part of the mine (e.g., Se-rich halo around Cu-rich zones) have been recognized in Mine D and provide an important framework for correlating the deep orebodies with the upper levels of the mine. Drilling below the current mine levels indicates that the massive sulfide and Cu stringer zones continue below 10,200 feet (3109 m) and highlight the remarkable continuity of the deposit downplunge with no end in sight. Two main ore suites have been recognized in the upper part of the mine and in Mine D: a low-temperature, polymetallic assemblage of Zn, Ag, Pb, Cd, Sn, Sb, As, Hg, ±Tl, ±W, and a higher-temperature suite of Cu, Co, As, Bi, Se, In, ±Ni. More than 25 different ore minerals and ore-related gangue minerals are present, including Co-As-sulfides, Cu-Sn-sulfides, Ag-minerals, and selenides. The massive ores consist mainly of pyrite, pyrrhotite, sphalerite, magnetite and chalcopyrite, together with minor galena, tetrahedrite, arsenopyrite, and native silver with a quartz and siderite gangue. Despite the high Ag content of the ores, the majority of the massive sulfides are remarkably Au poor except for a local gold zone that has been recognized in the deep mine in association with high-temperature mineralization. The trace elements in the ores exhibit strong zonation and diverse mineralogy. Spectacular albite porphyroblasts, up to 1 cm in size occur in the most Cu-rich ores of Mine D which are coincident with the peak of regional metamorphism and likely represent higher metamorphic or hydrothermal temperatures. Overall the orebodies have remained remarkably similar downplunge. However, unlike the upper part of the mine, pyrrhotite is dominantly hexagonal, only tetrahedrite was observed as the dominant sulfosalt, and magnetite occurs as both blebby porphyroblasts and as abundant intergrowths with sphalerite-chalcopyrite ores and siderite. These characteristics suggest that the deep mine has been subjected to higher metamorphic temperatures, possibly related to depth of burial, and that the original hydrothermal fluids may of had a lower H2S/CO2 and/or higher temperatures.
7
Wilson, Ryan. "Hydrothermal Fe-Carbonate Alteration Associated with Volcanogenic Massive Sulfide (VMS) Deposits in Cycle IV of the Noranda Mining Camp, Rouyn-Noranda, Quebec." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/22838.
Full textAbstract:
Massive sulfide deposits in the Noranda mining camp, northwestern Québec, are mainly associated with extensive footwall alteration defined by intense chloritization and sericitization. However, Fe-carbonate alteration also occurs in proximity to some deposits. To test the exploration significance of carbonate alteration in the camp, two areas of intense carbonate alteration were examined, around the small Delbridge deposit and near the new Pinkos occurrence in the Cyprus Rhyolite. Between 1969 and 1971, the Delbridge deposit produced 370,000 t of ore grading 9.6% Zn, 0.61% Cu, 110 g/t Ag, and 2.1 g/t Au. Recent drilling at the new Pinkos occurrence intersected 2.64 m of massive to semi-massive sulfides grading 8.1% Zn and 18.2 g/t Ag. Alteration mapping has shown that the distribution of Fe-carbonates can be used to identify vertically extensive zones of hydrothermal upflow at both properties. At Delbridge, intense Fe-carbonate alteration in brecciated rhyolite defines a pipe-like upflow zone that extends vertically for up to 300 m within the stratigraphic footwall of the massive sulfides and 100 m into the hanging wall. The location of known massive sulfide mineralization coincides with the intersection of the alteration pipe and a favorable horizon marked by the occurrence of fine-grained volcaniclastic rocks. At Pinkos, a similar zone of Fe-carbonate alteration occurs in outcrops of coherent rhyolite. Fe-carbonate alteration is most intensely developed along polygonal cooling fractures in massive rhyolite and decreases in intensity towards the centers of the columns. Fe-carbonate stringers and locally abundant matrix carbonate occur in fragmental rocks at the stratigraphic top of the coherent rhyolite flows and are most intense at the location of sulfide-bearing outcrops that mark the known mineralized horizon. Whereas Fe-carbonate alteration defines the central part of the hydrothermal upflow zones at both properties, disseminated pyrite occurs at the margins and is widespread outside the main upflow zones. This may indicate that Fe-carbonate in the main upflow zones formed at the expense of earlier disseminated sulfides. Replacement of pyrite by synvolcanic Fe-carbonate alteration at Delbridge and Pinkos can probably be attributed to a relatively high concentration of dissolved CO2, possibly of magmatic origin, in the main-stage ore-forming fluids.
8
Jamieson, John William. "Tracing sulfur sources in an Archean hydrothermal system using sulfur multiple isotopes a case study from the Kidd Creek volcanogenic massive sulfide deposit /." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2697.
Full textAbstract:
Thesis (M.S.) -- University of Maryland, College Park, 2005Thesis research directed by: Geology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
9
Steeves, Nathan. "Mineralization and Alteration of the Late Triassic Glacier Creek Cu-Zn VMS Deposit, Palmer Project, Alexander Terrane, Southeast Alaska." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/23654.
Full textAbstract:
The Glacier Creek volcanogenic massive sulfide (VMS) deposit is hosted within Late Triassic, oceanic back-arc or intra-arc, rift-related, bimodal volcanic rocks (Hyd or Tats Group) of the allochthonous Alexander terrane known as the Alexander Triassic Metallogenic Belt (ATMB). The deposit presently consists of four tabular massive sulfide lenses with a resource of 4.75 Mt. at 1.84% Cu, 4.57% Zn, 0.15% Pb, 0.28 g/t Au and 29.07 g/t Ag. A deposit-scale thrust fault offsets stratigraphy along the axial surface of a deposit-scale anticline.
The massive sulfide lenses are barite-rich and are divided into 6 main ore-types based on mineral assemblages. There is a large range of sphalerite compositions, with low-Fe sphalerite dominant throughout the lenses and high-Fe sphalerite at the top and bottom of the lenses in pyrrhotite-rich zones. Lenses contain anomalous Sb, Hg and Tl. Gangue minerals include barite, quartz, barian-muscovite, calcite, albite, highly subordinate chlorite and locally hyalophane and celsian. Overlying massive sulfide is a tuffaceous hydrothermal sediment with anomalous REE patterns and local hyalophane.
The general footwall to all four lenses is a thick unit of coherent to volcaniclastic feldspar-phyric basalt containing extensive lateral alteration. Four alteration facies are recognized based on mineral assemblages. Mass balance calculations for the footwall indicate general gains of S, Fe, Si and K with coincident loss of Ca, Na and Mg, along with trace element gains of Tl, Sb, Hg, Ba, Zn, Cu, As and loss of Sr with increased alteration intensity. Short wavelength infrared (SWIR) spectroscopy shows a general decrease in Na, K and Al content of muscovite and increase of Fe+Mg and Ba content towards ore.
Integrated petrographic, mineral, chemical and sulfur-isotope data suggest a transition during deposit formation, from high-temperature, acidic, reduced hydrothermal fluids mixing with oxidized, SO4-rich seawater, to later cooler, low fO2-fS2 conditions of formation and a lack of SO4 in seawater.
10
Prior, Glen James Carleton University Dissertation Earth Sciences. "Volcanology and geochemistry of archean rhyolites and related volcaniclastic rocks associated with the Kidd Creek volcanogenic massive sulfide deposit, Abitibi Greenstone Belt, Superior Province, Canada." Ottawa, 1996.
Find full text
11
Drieberg, Susan L. "The magmatic-hydrothermal architecture of the Archean Volcanic Massive Sulfide (VMS) System at Panorama, Pilbara, Western Australia." University of Western Australia. School of Earth and Geographical Sciences, 2003. http://theses.library.uwa.edu.au/adt-WU2004.0064.
Full textAbstract:
[Truncated abstract. Formulae and special characters can only be approximated here. Please see the pdf version of this abstract for an accurate representation.] The 3.24 Ga Panorama VMS District, located in the Pilbara Craton of Western Australia, is exposed as a cross-section through subvolcanic granite intrusions and a coeval submarine volcanic sequence that hosts Zn-Cu mineralization. The near-complete exposure across the district, the very low metamorphic grade, and the remarkable preservation of primary igneous and volcanic textures provides an unparalleled opportunity to examine the P-T-X-source evolution of a VMS ore-forming system and to assess the role of the subvolcanic intrusions as heat sources and/or metal contributors to the overlying VMS hydrothermal system. Detailed mapping of the Panorama VMS District has revealed seven major vein types related to the VMS hydrothermal system or to the subvolcanic intrusions. (1) Quartz-chalcopyrite veins, hosted in granophyric granite immediately beneath the granite-volcanic contact, formed prior to main stage VMS hydrothermal convection, and were precipitated from mixed H2OCO 2-NaCl-KCl fluids with variable salinities (2.5 to 8.5 wt% NaCl equiv). (2) Quartz-sericite veins, ubiquitous across the top 50m of the volcanic sequence, were formed from an Archean seawater with a salinity of 9.7 to 11.2 wt% NaCl equiv at temperatures of 90° to 135°C. These veins formed synchronous with the regional feldspar-sericite-quartz-ankerite alteration during seawater recharge into the main stage VMS hydrothermal convection cells. (3) Quartz-pyrite veins hosted in granophyric granite, and (4) quartz-carbonate-pyrite veins hosted in andesitebasalt, also formed from relatively unevolved Archean seawater (5.5 to 10.1 wt% NaCl equiv; 150° to 225°C), but during the collapse of the VMS hydrothermal system when cool, unmodified seawater invaded the top of the subvolcanic intrusions. (5) Quartz-topaz-muscovite greisen, (6) quartz-chlorite-chalcopyrite vein greisen, and (7) hydrothermal Cu-Zn-Sn veins are hosted in the subvolcanic intrusions. Primary H2O-NaCl-CaCl2 fluid inclusions in the vein greisens were complex high temperature hypersaline inclusions (up to 590°C and up to 56 wt% NaCl equiv). The H2O-CO2-NaCl fluid inclusions in the Cu-Zn-Sn veins have variable salinities, ranging from 4.9 to 14.1 wt% NaCl equiv, and homogenization temperatures ranging from 160° to 325°C. The hydrothermal quartz veins and magmatic metasomatic phases in the subvolcanic intrusions were formed from a magmatic-hydrothermal fluid that had evolved through wallrock reactions, cooling, and finally mixing with seawater-derived VMS hydrothermal fluids.
12
Schmandt, Danielle. "Mineralogy and origin of Zn-rich horizons within the arctic volcanogenic massive sulfide deposit, Ambler District, Alaska." 2009. http://hdl.handle.net/10090/8994.
Full text
13
Danielson, Thomas J. "Age, paleotectonic setting, and common Pb isotope signature of the San Nicolás volcanogenic massive sulfide deposit, southeastern Zacatecas State, central Mexico." Thesis, 2001. http://hdl.handle.net/2429/11279.
Full textAbstract:
The San Nicolas deposit is a world class polymetallic volcanogenic massive sulfide
(VMS) deposit located in southeastern Zacatecas State, central Mexico. The location of the
deposit in a metallogenic province previously thought to be barren with respect to VMS
mineralization, coupled with the large size of the deposit, make understanding the framework
within which the deposit formed important for further mineral exploration efforts in the
region, as well as for providing a more complete understanding of the geology of the region.
A geological, geochronological, lithogeochemical, and isotopic study was undertaken to
address the age of the volcano-sedimentary succession which hosts the San Nicolas deposit
and the paleotectonic setting in which it formed. U-Pb zircon dating of felsic volcanic units
within the volcano-sedimentary succession indicates that the volcanic rocks, and by
extension, the associated sulfide mineralization, formed in Late Jurassic time, at -148 Ma.
The succession comprises Upper Jurassic submarine, mafic and felsic flows,
volcaniclastic rocks, and hypabyssal intrusions. A limited number of thinly bedded, finegrained
clastic sedimentary rocks are locally intercalated with the volcanic units. Volcanic
rocks within the lower part of the succession (stratigraphically below and interfingering with
sulfide mineralization) display geochemical and isotopic characteristics which are consistent
with formation within a back-arc basin. Geochemical and isotopic characteristics of volcanic
rocks within the upper part of the succession (stratigraphically above VMS mineralization)
reflect a change in paleotectonic setting to a relatively juvenile volcanic arc environment.
Isotopic and geochronologic constraints suggest that the entire package was formed above
attenuated continental crust, perhaps as old as Precambrian in age.
In a separate, but related study, sulfide Pb isotope ratios were examined as a means of
distinguishing between styles of mineralization within central and southwestern Mexico. Pb
isotopic compositions from syngenetic and epigenetic mineralization in the region form two
distinct fields, suggesting that Pb isotopic compositions can be used as an inexpensive and
effective tool for discriminating between syngenetic and epigenetic mineralization. The
consistency of Pb isotopic compositions of sulfide minerals from syngenetic and epigenetic
deposits may also indicate a similar basement for all of central and southwestern Mexico.
14
Grant, Hannah Lucy Jane. "The distribution and controls on silver mineralization in the Main Zone of the 2.68 Ga Archean Hackett River Zn-Pb-Cu-Ag volcanogenic massive sulfide (VMS) deposit, Nunavut, Canada." Thesis, 2009. http://hdl.handle.net/1974/1719.
Full textAbstract:
The 2.68 Ga Zn-Pb-Cu-Ag Hackett River Main Zone (HRMZ) volcanogenic massive sulfide (VMS) deposit, within the Hackett River Greenstone Belt of the Archean Slave Craton is highly enriched in Ag (and Pb) compared to other VMS deposits of a similar age and type. The mineralization has been sub-divided into five categories based on mineralogy, textures and stratigraphic location: 1) disseminated footwall sulfides, 2) copper-rich stringer sulfides, 3) pyrite-poor sphalerite-pyrrhotite-chalcopyrite mineralization located at the top of the stringer zone, 4) mineralization in calc-silicate altered units and 5) sphalerite-pyrite massive sulfide mineralization. Using a mass-balance for Ag calculated from electron microprobe analyses, pyrrhotite and chalcopyrite in type 1 mineralization contain negligible Ag and in type 2, Bi-Ag-(Pb) sulfides, Ag-Bi-Se enriched galena and chalcopyrite are the dominant Ag hosts. Within type 3, freibergite and galena are the main silver hosts. In type 4, Ag is hosted in disseminated electrum and freibergite while freibergite in type 5 hosts 99% of the Ag. Overall, Ag-rich freibergite contains 79.4% of the total Ag, chalcopyrite hosts 6.3% and galena contains 1.8% of the Ag. Trace minerals such as electrum, stephanite, acanthite and Bi-bearing sulfides host the remainder of the Ag (12.5%) and have a restricted spatial distribution. Mineral assemblages have undergone pervasive recrystallization and annealing during amphibolite grade metamorphism with localized redistribution of base and precious metals from metamorphism at a grain scale only. Within freibergite and chalcopyrite, Ag directly substitutes for Cu within the mineral lattice and replaces Pb in galena by coupled substitution with Bi and to a lesser extent, Sb. The principal controls on Ag residence in the HRMZ are temperature and redox conditions (which varies with distance to the hydrothermal vent) and the ratio of Bi and Sb available for coupled substitution with silver within galena. Subsequent deposit-scale zone refining is the principal factor influencing the distribution of Ag. Lower temperatures and more oxidizing conditions favour partitioning of Ag into freibergite and less oxidizing conditions favour galena. At higher temperatures, the most reducing conditions favour incorporation of Ag in Ag-Bi rich galena (plus Se) and Bi-bearing sulfides or Ag-rich chalcopyrite under lesser reducing conditions.Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2009-03-12 10:46:49.993
15
Crowe, Douglas Edward. "Geochemistry of volcanogenic massive sulfide and high-grade Au granite-hosted ore deposits, southern Alaska ; and, Development and application of laser microprobe techniques for analysis of sulfur, carbon and oxygen isotope ratios." 1990. http://catalog.hathitrust.org/api/volumes/oclc/23277076.html.
Full textAbstract:
Thesis (Ph. D.)--University of Wisconsin--Madison, 1990.Typescript. Four plates on folded leaves in pocket. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
16
Weick, Reinhold James. "Petrography and stable isotope geochemistry of alteration and mineralization in the Rambler volcanogenic massive sulphide deposit, Baie Verte, Newfoundland /." 1993. http://collections.mun.ca/u?/theses,74228.
Full text