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Epithermal gold deposits in volcanic terranes. richard henley. 1993, Gold Metallogeny and Exploration. See full PDF download Download PDF. Related papers. Osmanlı Devleti'nde Kadınların Nüfus Sayımına Dahili ve Bu Süreçte Yaşanan Sorunlar.
rich ore fluids from the relatively shallow level granitoids implicated as ore-fluid sources. Gold deposits with atypical metal associations are a particularly diverse and controversial group, are …
Deformation and remobilisation of syngenetic massive sulphide deposits in volcanic and metamorphic terranes have yielded a large volume of literature (e.g ... Similar Pb-isotope contamination from the wall rocks was reported by Chen (1994) for the ores in the Jiapigou gold deposit, which is about 70 km northeast of the Hongtoushan deposit ...
The so-called 'mesothermal' gold deposits are associated with regionally metamorphosed terranes of all ages. Ores were formed during compressional to transpressional deformation processes at convergent plate margins in …
Metamorphic belts are complex regions where accretion or collision has added to, or thickened, continental crust. Gold-rich deposits can be formed at all stages of orogen evolution, so that evolving metamorphic belts contain diverse gold deposit types that may be juxtaposed or overprint each other. This partly explains the high level of controversy on the origin of some …
Abstract. Epigenetic gold deposits in metamorphic terranes include those of the Precambrian shields (approx 23,000–25,000 t Au), particularly the Late Archean greenstone belts a
Phanerozoic orogenic gold deposits worldwide are commonly considered to be formed from metamorphic devolatilization of marine carbonaceous sedimentary rocks. Here we show that …
The Sino-Vietnam (Tri, 1998) (=Huanan–Yangzi of Howell et al., 1985) terranes of northeastern Vietnam are the lateral extension of southern China (Fig. 2), which consists of Precambrian basement and Silurian metamorphic rocks intercalated with volcanic rocks, tightly folded during the Caledonian orogeny.The Huanan terrane amalgamated with the Yangzi …
Current unknowns for orogenic gold deposits include the following: (1) the precise tectonic setting and age of mineralization in many provinces, particularly in Paleozoic and older metamorphic belts; (2) the source of ore fluids and metals; (3) the precise architecture of the hydrothermal systems, particularly the relationship between first ...
The formation of the Air Piau Gold Deposit in North-East Peninsular Malaysia due to Permo–Triassic subduction and collision between Sibumasu and East Malaya blocks and resulted in several phases of deformation, contraction, and metamorphism. Kinematic and petrography study of quartz veins in Air Piau area observed whether following the foliation of …
Phanerozoic orogenic gold deposits worldwide are commonly considered to be formed from metamorphic devolatilization of marine carbonaceous sedimentary rocks. Here we show that the Yindongpo gold deposit from the Qinling orogen (central China) is genetically associated with the metamorphism of volcanic rocks during the late Paleozoic orogeny, which involved the closure …
It is concluded that the mineralization at Renco illustrates the rare case of a midcrustal high-grade metamorphic gold mineralization in southern Africa where the vast majority of Late Archean lode gold deposits are related to low-grade metamorphic granite-greenstone terranes.
Ore Geology Reviews 13 Ž1998. 7–27 Orogenic gold deposits: A proposed classification in the context of their crustal distribution and relationship to other gold deposit types D.I. Groves a a,), R.J. Goldfarb b, M. Gebre-Mariam a,c, S.G. Hagemann a, F. Robert d Centre for Teaching and Research in Strategic Mineral Deposits, Department of Geology and Geophysics, UniÕersity …
• Structurally hosted vein systems in metamorphic terranes Recent work by Groves and others (1998) ... Ore Shoots Control and Distribution of Gold Mineralization Kerrich and Feng (1992) make the point that quartz and quartz-carbonate veins are common in metamorphic belts. The majority of these veins are from a centimeter to a
Epigenetic gold deposits in metamorphic terranes include those of the Precambrian shields (approx 23,000-25,000 t Au), particularly the Late Archean greenstone belts and Paleoproterozoic fold belts, and of the late Neoproterozoic and younger Cordilleran-style orogens (approx 22,000 t lode and 15,500 t placer Au), mainly along the margins of Gondwana, Laurentia, and the more …
The types of mainly metallic mineralization found in metamorphic terranes are reviewed and an attempt is made to define the genetic relations between the mineralization and the metamorphic events.The terms metamorphosed, metamorphic, and metamorphogenic as applied to ores are also considered.The development of thought and the history of investigations on ores in …
Gold-quartz vein fields in metamorphic terranes such as greenstone belts provide evidence for the involvement of large volumes of fluids during faulting and may be products of seismic processes near the base of the seismogenic regime. In the Val d'Or district of the Abitibi greenstone belt, Canada, quartz-tourmaline-carbonate veins form a vein field (30 × 15 km) in …
Like the Otago Schist, in both terranes detrital rutile is identified as being the most important host mineral for W in the lowest metamorphic grade rocks, and its prograde metamorphic recrystallization (to ilmenite) makes significant amounts of W available for mobilization (0.65 and 1.85 g of W per tonne of rock from the Goldenville and ...
Multidisciplinary research carried out on primary gold ores in the evolving Cretaceous island arc terranes of the Dominican Republic has shown the existence of three groups of deposits and occurren...
Ridley et al. (2000) classified a number of orogenic gold deposits hosted in high-grade metamorphic rocks in the Yilgarn block, Western Australia, according to prominent minerals in the proximal ...
Anomalously gold-rich fluids may also occur in deeper metamorphic terrains, but representative regional-metamorphic fluid inclusions are difficult to relate to the formation of orogenic gold deposits due to the crustal-scale extent of these ore-forming systems (Groves, 1993), and because primary fluid inclusions are rare in regional metamorphic ...
Relationships among gold endowment, shear-zone trend, and geologic complexity, as measured by fractal dimensions, indicate that (1) ore fluids were focused into those parts of the shear zone with greatest misorientation from the regional trend, which define dilational sites during shearing and became the sites of world-class gold deposits; and ...
Deposits are also found in higher-grade metamorphic rocks, known as hypozonal gold deposits. These deposits are mostly hosted in amphibolite-facies rocks in greenstone belts and are characterized by high-temperature alteration assemblages such as garnet, diopside, hornblende, and K-feldspar and ore-forming temperatures as high as ~500–700 °C (Kolb et …
The new Hg isotope evidence is consistent with previous evidence for a sub-crustal source that includes (1) the occurrence of gold mineralization under retrograde metamorphic conditions in high-grade metamorphic terranes during which significant devolatilization was absent (Groves et al., 2020); and (2) a range of compatible geochemical …
grade metamorphic granite-greenstone terranes. Introduction IN CONTRAST to the vast majority of lode gold deposits in Zim- babwe that are associated with Late Arehean greenschist facies granite-greenstone terranes of the Zimbabwe eraton, the Reneo mine is one of the very few economic-grade gold deposits
From overlaps in the tectono-metamorphic history, it is concluded that gold mineralization occurred during two tectonic events, affecting the eastern Dharwar craton in south India between ca. 2550 – 2530 Ma: (1) The assemblage of various terranes of the eastern block, and (2) a tectono-magmatic event, which caused late- to posttectonic ...
Epigenetic gold deposits in metamorphic terranes include those of the Precambrian shields (approx 23,000–25,000 t Au), particularly the Late Archean greenstone belts and Paleoproterozoic fold belts, and of the late Neoproterozoic and younger Cordilleran-style orogens (approx 22,000 t lode and 15,500 t placer Au), mainly along the margins of Gondwana, …
Gold deposits are widely distributed in the Archean southern Kalgoorlie and Norseman greenstone terranes, Eastern Goldfields superterrane, Western Australia, which have collectively produced more ...
Metamorphic belts are complex regions where accretion or collision has added to, or thickened, continental crust. Gold-rich deposits can be formed at all stages of orogen evolution, so that …
Similarly, large gold endowments in numerous juvenile oceanic terranes, indicate an enriched SCLM cannot be the direct gold source. A crustal or subduction-zone metamorphic model remains the most viable ore-genesis model that can be …