scholarly journals Geology of the Doris North gold deposits, northern Hope Bay volcanic belt, SlaveStructural Province, Nunavut

2003 ◽  
Author(s):  
R L Carpenter ◽  
R L Sherlock ◽  
C Quang ◽  
P Kleespies ◽  
R McLeod
Keyword(s):  
Volcanic Belt ◽  
Gold Deposits ◽  
Hope Bay

Geochemical and metallogenic relations in volcanic rocks of the southern Slave Province: implications for late Neoarchean tectonics

2006 ◽  
Vol 43 (12) ◽  
pp. 1835-1857 ◽  
Author(s):  
A M Goodwin ◽  
M B Lambert ◽  
O Ujike
Keyword(s):  
Plate Tectonics ◽  
Early Stage ◽  
Volcanic Rocks ◽  
Volcanic Belt ◽  
Gold Deposits ◽  
Tectonic Plates ◽  
Slave Province ◽  
Volcanogenic Massive Sulphide ◽  
Lode Gold Deposits ◽  
Volcanic Belts

Late Neoarchean volcanic belts in the southern Slave Province include (1) in the east, the Cameron River – Beaulieu River belts, which are characterized by stratigraphically thin, flow-rich, classic calc-alkaline, arc-type sequences with accompanying syngenetic volcanogenic massive sulphide deposits; and (2) in the west, the Yellowknife belt, which is characterized by stratigraphically thick, structurally complex, pyroclastic-rich, adakitic, back-arc basin-type sequences, with accompanying epigenetic lode-gold deposits. The volcanic belt association bears persuasive chemical evidence of subduction-initiated magma generation. However, the greenstone belts, together with coeval matching patterned belts in Superior Province of the southern Canadian Shield, bear equally persuasive evidence of prevailing autochthonous–parautochthonous relations with respect to component stratigraphic parts and to older gneissic basement. The eastern and western volcanic belts in question are petrogenetically ascribed to a "westerly inclined" (present geography) subduction zone(s) that produced shallower (east) to deeper (west), slab-initiated, mantle wedge-generated, parent magmas. This early stage microplate tectonic process involved modest mantle subduction depths, small tectonic plates, and small sialic cratons. In the larger context of Earth's progressively cooling, hence subduction-deepening mantle, this late Neoarchean greenstone belt development (2.73–2.66 Ga) merged with the massive end-Archean tonalite–trondhjemite–granodiorite–granite (TTGG) "bloom" (2.65–2.55 Ga), resulting in greatly enhanced craton stability. Successive subduction-deepening, plate-craton-enlarging stages, with appropriate metallotectonic response across succeeding Proterozoic time and beyond, led to modern-mode plate tectonics.

Recycling of mercury from the atmosphere-ocean system into volcanic-arc–associated epithermal gold systems

Geology ◽  
2020 ◽  
Author(s):  
Changzhou Deng ◽  
Guangyi Sun ◽  
Yimeng Rong ◽  
Ruiyang Sun ◽  
Deyou Sun ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Marine Sediments ◽  
Northeast China ◽  
Active Continental Margin ◽  
Volcanic Belt ◽  
Gold Deposits ◽  
Ore Deposits ◽  
Epithermal Gold ◽  
Volcanic Arc ◽  
South China Craton

Photochemical processes generate mass-independent fractionation (MIF) of mercury (Hg) isotopes in the atmosphere-ocean system, and the subduction of marine sediments or hydrated oceanic crust may recycle the resultant Hg isotope signature into the volcanic-arc environment. This environment typically hosts epithermal gold deposits, which are characterized by a specific Hg-Sb-As metal association. We investigated the Hg isotopic composition of seven volcanic-arc–related epithermal gold deposits in northeast China and revisited the isotopic composition of Hg in hydrothermal ore deposits in circum-Pacific and Mediterranean volcanic arcs. The gold ore samples in northeast China mostly display positive Δ199Hg values (0.11‰ ± 0.07‰, 1σ, n = 48) similar to those observed in the Pacific Rim (0.07‰ ± 0.09‰, 1σ, n = 182) and the Mediterranean Cenozoic volcanic belt (0.09‰ ± 0.08‰, 1σ, n = 9). Because Hg in marine sediments and seawater has positive Δ199Hg, we infer that Hg-bearing epithermal deposits in active continental margin settings receive most Hg from recycled seawater in marine sediments, through the release of Hg by dehydration from the subducting oceanic slab. However, negative to near-zero Δ199Hg values were observed in Hg-bearing deposits in the South China craton (–0.09‰ ± 0.05‰, 1σ, n = 105) and in the intraplate magmatic-hydrothermal Almadén Hg deposit in Spain (–0.02‰ ± 0.06‰, 1σ, n = 26), which are considered to relate to basement and mantle sources, respectively. Hg isotopes have the potential to trace lithospheric Hg cycling.

scholarly journals ON THE GOLD MINERALIZATION IN WEATHERING CRUSTS OF THE RYBACHY SITE (WESTERN SIKHOTE-ALIN)

2021 ◽  
Vol 24 (1) ◽  
pp. 26-33
Author(s):  
E.V. Nigai
Keyword(s):  
Gold Mineralization ◽  
Raw Materials ◽  
Volcanic Belt ◽  
Gold Deposits ◽  
Gold Content ◽  
Mountain Areas ◽  
Alluvial Deposits ◽  
Weathering Crusts ◽  
Folded Structures ◽  
Eastern Institute

The author addresses an issue of gold presence in pre-Quaternary crusts of weathering that are widespread in sub-mountain areas of the doming-block geomorphological structures of the Amur Region, the Khabarovsk and Primorsky Territories along the periphery of large- and medium-sized Cenozoic basins and depressions. For a more detailed mining and geological study and assessment of the gold content of the weathering crusts, we recommended the Rybachy site as one of these objects (insufficiently studied), and the entire Mukhenskaya area as a promising one. These sites are located in the zone of articulation of the eastern side of the Middle Amur Depression with the folded structures of the West Sikhote-Alinsky volcanic belt. The author gives examples of large gold deposits, related to weathering crusts with their brief description (Olympiada, Kuranakh), as well as a brief description of alluvial deposits of weathering crust (sub-basalt cl.Paskhalny, an eluvial-alluvial placer of the Bolotisty Stream). The search work of the DVIMS (Far Eastern Institute of Mineral Raw Materials) in 2002 indicated the potential of weathering crusts within the Rybachy prospect for gold mineralization. This is supported by elevated gold in heavy mineral concentrates from the linear weathering crusts and residual blankets, as well as from non-commercial placers (from 0.01 to 4.0 g/t and higher); the occurrence of fracture zones, brecciation, secondary silicification close by fractures, and abundant Late Cretaceous silicic and intermediate dikes. Zones of hydrothermally altered rocks (silicification, chloritization, sericitization, argillization) are widespread here.

Volcanic Stratigraphy, Geochronology, and Gold Deposits of the Archean Hope Bay Greenstone Belt, Nunavut, Canada

2012 ◽  
Vol 107 (5) ◽  
pp. 991-1042 ◽  
Author(s):  
R. L. Sherlock ◽  
A. Shannon ◽  
M. Hebel ◽  
D. Lindsay ◽  
J. Madsen ◽  
...  
Keyword(s):  
Greenstone Belt ◽  
Gold Deposits ◽  
Volcanic Stratigraphy ◽  
Hope Bay
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