The Martabe Au-Ag high-sulfidation epithermal deposits, Sumatra

The majority of epithermal Au-Ag mineralization in the district is characterized as high-sulfidation, based on the sulfide and sulfosalt mineral assemblage and advanced argillic alteration. Ore mineralization consists of enargite-luzonite+tetrahedrite-tennantite-pyrite in veins, vugs and as breccia matrix.

Epithermal Au-Ag and Porphyry Cu-Au Exploration

This introduction sets out the terminology used for epithermal Au-Ag and porphyry Cu-Au ore deposit types (figure 1), in order to facilitate the more detailed analysis of some exploration tools (alteration, structure, breccias) and then the deposit types. That analysis will then facilitate a consideration of what geological features an ...

Mineralogy and geochemical environment of formation of …

The Perama Hill deposit is a high-sulfidation Au-Ag-Te-Se epithermal system hosted in silicic- and argillic altered andesitic rocks and overlying sandstones, which were emplaced on the eastern margin of the Petrota graben, northeastern Greece. The deposit evolved from an early stage silica-pyrite rock and argillic alteration followed by …

Protracted metallogenic and magmatic evolution of the …

The HS epithermal Au-Ag orebody contains a reserve of 33.86 Mt @ 0.69 g/t Au, 9.42 g/t Ag, and a resource of 3.056 Mt @ 0.43 g/t Au, 2.71 g/t Ag (Alamos Gold 2022). The HS epithermal orebody is hosted by the Oligocene basaltic andesite lava flow and lithic-crystal tuffs.

A case of Te-rich low-sulfidation epithermal Au-Ag deposits …

DOI: 10.1016/j.oregeorev.2022.105158 Corpus ID: 253013886; A case of Te-rich low-sulfidation epithermal Au-Ag deposits in a calc-alkaline magmatic arc, NE China @article{Gao2022ACO, title={A case of Te-rich low-sulfidation epithermal Au-Ag deposits in a calc-alkaline magmatic arc, NE China}, author={Shen Gao and Albert H. Hofstra and …

The magmatic origin of propylitic alteration of the …

The origin of propylitic fluids in intermediate sulfidation mineralization has not been investigated in detail. Here, we present an extensive petrographic, geochemical, and isotopic (O-H-Sr) study of propylitic epidote, chlorite, and calcite from the Zhengguang intermediate sulfidation epithermal Au-Zn deposit, NE China. Propylitic minerals can be …

Supergene Alteration of Primary Ore Assemblages fromLow-Sulfidation Au

The Capricornio epithermal Au-Ag vein system is located within the Chilean Paleocene-Eocene metallogenic belt, 60 km ENE of Antofagasta in the physiographic Central Depression, between the Coastal ...

Noble gas data from Goldfield and Tonopah epithermal Au …

This association combined with a statistically significant correlation between 3 He/ 4 He and primary precious metal (Au or Ag) relative grade observed for epithermal …

(PDF) Changes in Ag/Au Ratio due to Mineralization Types

Abstract In the epithermal vein-type Sirawai Au–Ag deposit, zonings of Ag/Au ratios (Ag/Au) and Cu and Pb–Zn zones of the type-1 ore (early stage) are observed. It is estimated that these ...

(PDF) Epithermal ore deposits: First-order features relevant …

In particular, the epithermal Au-Ag system is a well-known hydrothermal Au deposit class, constituting about 8% of gold resources (including past products, reserves, and current resources ...

Gold-telluride-sulfide association in the Sandaowanzi epithermal Au-Ag …

Tellurides of Au, Ag, Pb and other base metals commonly occur as trace minerals in numerous magmatic-hydrothermal mineral deposits, especially in epithermal gold deposits which are temporally and spatially associated with alkaline to calc-alkaline magmatism (Sillitoe 2002; Ciobanu et al. 2006).Normally in these deposits sulfides are …

The Discovery of the Cu (Au-Ag) Epithermal Deposit in the …

DOI: 10.1111/1755-6724.12380_32 Corpus ID: 140163985; The Discovery of the Cu (Au-Ag) Epithermal Deposit in the Duolong Ore Concentrating Area, Northern Tibet @article{Tang2014TheDO, title={The Discovery of the Cu (Au-Ag) Epithermal Deposit in the Duolong Ore Concentrating Area, Northern Tibet}, author={Juxing Tang and Xing …

Geology, porphyry Cu Au, and epithermal Cu Au Ag …

The epithermal Au-Ag mineralization associated with quartz veins at Kaidundu and elsewhere in the district show many mineralogical and textural features of low-sulfidation deposits, such as low total sulfide contents ( < 5 vol.%); comb and cockade quartz partly filling prominent open vugs; chalcedonic, banded silica; weak alteration of …

Controls to low sulphidation epithermal Au-Ag …

Chalcedony-ginguro epithermal Au-Ag deposits commonly display bonanza Au grades and occur as generally Ag-rich banded veins comprising chalcedony, adularia, quartz pseudomorphing platy calcite and ginguro black sulphidic material described by 19th century Japanese miners. While much of the gangue

(PDF) PACIFIC RIM EPITHERMAL Au-Ag

Epithermal Au-Ag deposits form in the upper 1 km of the crust and are therefore best preserved in the less eroded Pacific rim arcs, although also recognised elsewhere. Two profoundly different ore ...

Exploration for epithermal Au–Ag deposits in New …

In New Zealand, prospecting and exploration permit holders must report their exploration results to the government (NZP&M). Since the 1970s, this has gen-erated more than 2000 such reports related to epithermal Au–Ag exploration. The supplied infor-mation is held con dential until the permit expires. fi.

Exploration for epithermal Au–Ag deposits in New …

The known epithermal Au–Ag deposits in New Zealand are all volcanic associated, with features characteristic of low (locally to intermediate) sulphidation types, in which the Au and Ag are mainly contained in quartz veins, with little disseminated Au and Ag in the wallrocks except for that in some rhyolite-hosted deposits such as ...

New isotopic evidence bearing on bonanza (Au-Ag) …

shallow geothermal waters or formation of metallic (Au, Ag, Cu phases) nanoparticles at depth from magmatic fluids prior to encountering the geothermal system. The latter is most consistent with ore textures that indicate physical transport and aggregation of nanoparticles were significant ore-forming processes. The recognition that epithermal ...

A review of intermediate sulfidation epithermal deposits …

The average grade of samples showing colloform texture (178.8 ppm Ag and 1.1 ppm Au) is distinctly higher than those without this (17.2 ppm Ag and 0.2 ppm Au) in epithermal Ag-Au deposits at Guanajuato, Mexico (Moncada et al., 2012) confirming that boiling (with related cracking and depressurization) and subsequent sealing (deposition …

Evolution of the Peak Hill high-sulfidation epithermal Au–Cu …

The early Palaeozoic Macquarie Arc, southeastern Australia, hosts a variety of major late Ordovician to earliest Silurian subduction-related deposits (e.g., Cadia East, Ridgeway, Cadia Hill, Cowal and Northparkes). However, there is uncertainty about whether coeval high-sulfidation epithermal deposits, which occur in intra-oceanic metallogenic …

A track record of Au–Ag nanomelt generation during fluid …

A similar process could take place in the studied samples considering that euhedral Au–Ag NPs are larger in size (100–350 nm) compared to the droplet-like, smaller (10–20 nm) Au–Ag NPs ...

Minerals | Free Full-Text | Precious-Metal Mineralization and …

The Biche-Kadyr-Oos epithermal Au-Ag ore occurrence is a prospective object in the Ak-Sug porphyry copper ore cluster (Eastern Sayan) in the northern part of the Central Asian orogenic belt (CAOB). The mineralization consists of gold-sulfide-quartz and gold-polysulfide-carbonate-quartz veins with argillic zones in the Lower Cambrian …

The Discovery of the Cu (Au-Ag) Epithermal Deposit in the …

DOI: 10.1111/1755-6724.12380_32 Corpus ID: 140163985; The Discovery of the Cu (Au-Ag) Epithermal Deposit in the Duolong Ore Concentrating Area, Northern Tibet …

Epithermal Gold for Explorationists

Epithermal gold (± Cu & Ag) deposits form at shallower crustal levels than porphyry Cu-Au systems, and are primarily distinguished as low and high sulphidation using criteria of varying gangue and ore mineralogy, deposited by the interaction of different ore fluids with host rocks and groundwaters. Low sulphidation deposits are in turn further ...

Hydrothermal alteration mineralogical footprints for New …

Epithermal Au-Ag veins of the Hauraki goldfield are mostly hosted by volcanic rocks and are enclosed by extensive zones of hydrothermal alteration that are generally 6–50 km² in areal extent.

The Hishikari Au-Ag Epithermal Deposit, Japan: Oxygen and …

Genesis of epithermal Au-Ag mineralization of the Koryu Mine, Hokkaido, Japan Economic Geology. Epithermal gold mineralization in an old volcanic arc; the Jacinto Deposit, Camagueey District, Cuba Economic Geology. Mineralogical, Fluid Inclusion, and Multiple Isotope (H-O-S-Pb) Constraints on the Genesis of the Sandaowanzi Epithermal …

Direct Observation and Measurement of Au and Ag in Epithermal …

The average Ag concentration is c. 32 ppm and Au is c. 41 ppm but the maximum concentrations of both may reach several 100's to 1000 ppm. Calcite forms a coating on the inner surface of the ...

(PDF) The Tuscarora Au-Ag District: Eocene Volcanic-Hosted

(Cont.) 357 EPITHERMAL Au-Ag DEPOSITS IN THE TUSCARORA DISTRICT, NEVADA throughout the district, average slightly higher in the silver zone; however, the only high concentration (276 ppm) is in a sample from the Modoc vein in the gold zone. Samples from the Navajo mine at the south end of the Navajo vein have high concentrations of Au, Hg, …

Full article: Geophysical signatures of New Zealand …

Epithermal Au-Ag deposits can be successfully targeted with geophysics at a range of scales. Airborne magnetic and gamma-ray spectrometer surveys can identify the zone of …

The Tuscarora Au-Ag District: Eocene Volcanic-Hosted …

Ag/Au and low Ag/Au deposits in the Tuscarora district, and between Tuscarora epithermal mineralization and Carlin-type deposits. Previously, little was known about the Eocene geology of the region (Brooks et al., 1995a, b) or about the Tuscarora district, although Emmons (1910) and Nolan (1936) identified the apparent juxtaposition of the …

WORLD GOLD PACIFIC RIM EPITHERMAL Au-Ag

Epithermal Au-Ag deposits form in the top 1 km of the crust and so dominate in more youthful, less eroded crustal settings. Nevertheless, tectonic processes have preserved many examples in the

EPITHERMAL AU-AG DEPOSIT TYPES

The low sulphidation epithermal banded chalcedony-ginguro Au-Ag deposits (formerly termed adularia-sericite epithermal Au-Ag) host local bonanza Au-Ag in the ginguro sulphidic...

Full article: The lithogeochemical signatures of hydrothermal

Waihi hosts multiple Au–Ag epithermal deposits including the large (> 7 Moz Au) Martha deposit (Christie et al. Citation 2007; Figure 1). The Waihi area is an ideal study site for assessing the mineralogical and geochemical alteration footprints of epithermal vein systems, and associated Au–Ag deposits, as the lithological host for ...

Direct observation and measurement of Au and Ag in …

This study provides evidence for the presence of colloidal Au-Ag particles in epithermal fluids. These were observed using scanning electron microscopy (SEM), in …