Tectonic Setting, Characteristics, and Regional Exploration Criteria for Gold Mineralization in the Altaid Orogenic CollageThe Tien Shan Province as a Key Example

Author(s):  
Alexander Yakubchuk ◽  
Andrew Cole ◽  
Reimar Seltmann ◽  
Vitaly Shatov
2012 ◽  
Vol 20 (4) ◽  
pp. 317-345 ◽  
Author(s):  
K. E. Degtyarev ◽  
T. Yu. Tolmacheva ◽  
A. V. Ryazantsev ◽  
A. A. Tret’yakov ◽  
A. S. Yakubchuk ◽  
...  

Author(s):  
Dennis Sánchez-Mora ◽  
Christopher R.M. McFarlane ◽  
James A Walker ◽  
David R. Lentz

Gold mineralization at Williams Brook in northern New Brunswick is hosted within the Siluro-Devonian, bimodal, volcano-sedimentary rocks of the Tobique-Chaleur Zone (Wapske Formation). Gold mineralization occurs in two styles: 1) as disseminations (refractory gold) in rhyolite, and 2) in cross-cutting quartz veins (free gold). Dating of the felsic volcanic host rocks by in situ LA-ICP-MS zircon U-Pb geochronology returned ages of 422 ± 3, 409 ± 2, 408 ± 3, 405 ± 2, 401 ± 9 Ma. Zr/Y of subvolcanic felsic intrusion (<8 for syn-mineralization and >8 for post-mineralization) suggests evolution from transitional to more alkalic affinities. Two mineralizing events are recognized; the first is a disseminated mineralization style formed at ~422–416 Ma and the second consists of quartz vein-hosted gold emplaced at 410–408 Ma. Felsic rocks from Williams Brook and elsewhere in the Tobique Group (i.e. Wapske, Costigan Mountain, and Benjamin formations), and the Coastal Volcanic Belt have similar Th/Nb ratios of ~0.1 to 1, reflecting similar levels of crustal contamination, and similar Nb and Y content, suggesting A-type affinities. These data indicate a similar environment of formation. Regionally, mafic rocks show similar within-plate continental signatures and an E-MORB mantle source that formed from partial melts of 10–30%. Mafic volcanic rocks from Williams Brook have a more alkaline affinity (based on Ti/V), and derivation from lower percentage partial melting (~5%). The chemical and temporal variations in the Williams Brook rocks suggest that they were erupted in an evolving transpressional tectonic setting during the oblique convergence of Gondwana and Laurentia.


1975 ◽  
Vol 17 (10) ◽  
pp. 1121-1127 ◽  
Author(s):  
G.V. Pisemskiy ◽  
S. D. Slier ◽  
T. P. Zhadnova ◽  
L. M. Ganzha ◽  
A. C. Pletnev ◽  
...  

2020 ◽  
Vol 02 (10) ◽  
pp. 70-82
Author(s):  
Movlanov J.J. ◽  
◽  
S.M. Koloskova ◽  

Geochemical testing covered the entire territory of Uzbekistan, but with varying degrees of detail. Most, 85-88% of the republic's area is covered with Mesozoic and Cenozoic sediments, with which exogenous deposits are associated. Pre-Mesozoic formations - the environment of localization of endogenous deposits, confined to the mountain systems of the Median and South Tien Shan. Mountain heights with outcrops of Pre-Mesozoic rocks occupy about 12-15% in area, the rest is in semi-closed and closed territories. Primary halos are recorded on the surface and at depth, secondary ones on the surface, as well as near it: below the raft - in water, above - in the surface atmosphere. Improving forecasting efficiency in regional geochemical works, interpretation and assessment of different-rank ore-generating geochemical anomalies in complex landscape-geological conditions.


2017 ◽  
Vol 86 ◽  
pp. 537-547 ◽  
Author(s):  
D. Konopelko ◽  
R. Klemd ◽  
S.V. Petrov ◽  
F. Apayarov ◽  
B. Nazaraliev ◽  
...  

Author(s):  
Leela Witvoet

The Seabee Gold Operation, located in northern Saskatchewan, ~125 km northeast of La Ronge, has been in continuous operation since 1991. The host rocks for the gold mineralization are the volcanic and plutonic rocks of the Pine Lake greenstone belt, which represent a volcanic island arc terrane that was accreted onto proto-North America and was metamorphosed during the Trans-Hudson orogen ca. 1.8 billion years ago. An older volcanic package (“A”) is separated from a younger volcanic package (“B”) by a regional unconformity. The Laonil Lake Intrusive Complex, which hosts the Seabee gold deposit, and the Eisler Intrusive Complex are thought to be part of Assemblage A, based on an imprecise age determination of the Laonil Lake Intrusive Complex and by initial comparative observation of the Laonil and Eisler Intrusive Complexes. This study aims to better understand the age and tectonic setting of the Laonil Lake Intrusive Complex and its relationship to the nearby Eisler Intrusive Complex—which might represent the same igneous event, and therefore be of interest as an exploration target. Methods to test their correlation include whole rock geochemistry, petrography, Sm-Nd isotopes, and U-Pb geochronology. Preliminary modal mineralogy of samples was used to derive rock names (using pre-metamorphic names); the Laonil Lake Intrusive Complex samples are quartz gabbro and tonalite, whereas the Eisler Intrusive Complex samples are tonalite, quartz gabbro, gabbro, and pyroxenite. The preliminary age determinations of the Laonil Lake and Eisler Intrusive Complexes are ca. 1877 Ma and 1884 Ma, respectively. The geochemical signatures of all samples suggest derivation in a volcanic arc setting. The samples exhibit a slight LREE enrichment and epsilon Nd values (+3.61 to +4.65) that suggest a depleted mantle source for the magmas. The ages of Laonil Lake and Eisler Intrusive Complexes suggest that both are part of Assemblage A. The results of this research will provide constraints on the correlation between the Pine Lake greenstone belt and other volcanic belts in the Trans-Hudson orogeny.


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