The Geodynamics of World-Class Gold Deposits

Gold in 2000 ◽  
2000 ◽  
pp. 501-551 ◽  
Keyword(s):  
2018 ◽  
Vol 9 (4) ◽  
pp. 1163-1177 ◽  
Author(s):  
David I. Groves ◽  
M. Santosh ◽  
Richard J. Goldfarb ◽  
Liang Zhang

2018 ◽  
Vol 54 (1) ◽  
pp. 378-391 ◽  
Author(s):  
Jun Deng ◽  
Li-Qiang Yang ◽  
Rui-Hong Li ◽  
David I. Groves ◽  
M. Santosh ◽  
...  

2021 ◽  
Vol 6 (1) ◽  
pp. 19
Author(s):  
Hugo Paiva Tavares de Souza ◽  
Carlos Marcello Dias Fernandes ◽  
Ricardo de Freitas Lopes ◽  
Stéphane Amireault ◽  
Marcelo Lacerda Vasquez

The southeastern region of the Amazonian Craton has been the target of several metallogenetic surveys, which recently led to the identification of the world-class Volta Grande gold deposit with gold reserves of ~3.8 Moz at 1.02 g/t. This deposit is located ~60 km southeast of Altamira city, Pará state, and is hosted by the Três Palmeiras intrusive greenstone belt that is located in the northern Bacajá tectonic domain (2.24–2.0 Ga). The mineralization is hosted by a high-level intrusive and mylonitized suite. Local kinematic indicators suggest dip-slip movement in which the greenstone moves up relative to the intrusive rocks. Native gold mostly occurs as isolated grains in centimeter-wide quartz veins and veinlets associated with pervasive carbonate alteration that was synchronous with dynamic metamorphism. Part of the gold is also associated with disseminated sulfides in this generally low-sulfide mineralization. These relationships are compatible with orogenic lode-type gold systems elsewhere. New petrographic studies from core samples along a stratigraphic profile reveal the presence of lava flows and dykes of rhyodacite, rhyolite, and plutonic rocks such as quartz monzonite, granodiorite, monzodiorite, and subordinate microgranite crosscutting an earlier style of mineralization. These rocks are characterized by potassic, propylitic, intermediate argillic, and/or carbonate hydrothermal alterations in selective, pervasive, or fracture-controlled styles. Within the hydrothermal volcano-plutonic sequence, gold occurs as disseminated isolated grains or replacing sulfides. Both native gold and sulfides are also present in centimetric quartz veinlets. Such features of the deposit are similar to those from porphyry-type and low- to intermediate-sulfidation epithermal systems already identified in the Amazonian Craton. The Volta Grande deposit data suggest a second mineralizing event, common in large-tonnage gold deposits, and can represent a new exploration guide.


2020 ◽  
Vol 132 (9-10) ◽  
pp. 1829-1844 ◽  
Author(s):  
Ashley Gumsley ◽  
Joaen Stamsnijder ◽  
Emilie Larsson ◽  
Ulf Söderlund ◽  
Tomas Naeraa ◽  
...  

Abstract U-Pb geochronology on baddeleyite is a powerful technique that can be applied effectively to chronostratigraphy. In southern Africa, the Kaapvaal Craton hosts a well-preserved Mesoarchean to Paleoproterozoic geological record, including the Neoarchean Ventersdorp Supergroup. It overlies the Witwatersrand Supergroup and its world-class gold deposits. The Ventersdorp Supergroup comprises the Klipriviersberg Group, Platberg Group, and Pniel Group. However, the exact timing of formation of the Ventersdorp Supergroup is controversial. Here we present 2789 ± 4 Ma and 2787 ± 2 Ma U-Pb isotope dilution-thermal ionization mass spectrometry (ID-TIMS) baddeleyite ages and geochemistry on mafic sills intruding the Witwatersrand Supergroup, and we interpret these sills as feeders to the overlying Klipriviersberg Group flood basalts. This constrains the age of the Witwatersrand Supergroup and gold mineralization to at least ca. 2.79 Ga. We also report 2729 ± 5 Ma and 2724 ± 7 Ma U-Pb ID-TIMS baddeleyite ages and geochemistry from a mafic sill intruding the Pongola Supergroup and on an east-northeast–trending mafic dike, respectively. These new ages distinguish two of the Ventersdorp Supergroup magmatic events: the Klipriviersberg and Platberg. The Ventersdorp Supergroup can now be shown to initiate and terminate with two large igneous provinces (LIPs), the Klipriviersberg and Allanridge, which are separated by Platberg volcanism and sedimentation. The age of the Klipriviersberg LIP is 2791–2779 Ma, and Platberg volcanism occurred at 2754–2709 Ma. The Allanridge LIP occurred between 2709–2683 Ma. Klipriviersberg, Platberg, and Allanridge magmatism may be genetically related to mantle plume(s). Higher heat flow and crustal melting resulted as a mantle plume impinged below the Kaapvaal Craton lithosphere, and this was associated with rifting and the formation of LIPs.


SEG Discovery ◽  
2005 ◽  
pp. 7-19
Author(s):  
John L. Muntean ◽  
Hartwig E. Frimmel ◽  
Neil Phillips ◽  
Jonathan Law ◽  
Russell Myers
Keyword(s):  

Editor’s note: This is the second of a two-part preview of an SEG-sponsored forum to be held in Reno, Nevada, on May 14, 2005. Meeting details are on p. 54.


Geology ◽  
2003 ◽  
Vol 31 (12) ◽  
pp. 1073 ◽  
Author(s):  
Richard J. Squire ◽  
John Mc. L. Miller
Keyword(s):  

2020 ◽  
pp. 709-734
Author(s):  
Gerard I. Tripp ◽  
Richard M. Tosdal ◽  
Thomas Blenkinsop ◽  
Jamie R. Rogers ◽  
Scott Halley

Abstract Neoarchean greenstone-hosted gold deposits in the Eastern Goldfields Superterrane of the Yilgarn craton of Western Australia are diverse in style, timing with respect to magmatic activity, structural environment, host rocks, and geochemical character. Geologic constraints for the range of gold deposits indicate deposit formation synchronous with volcanism, synchronous with syn- and postvolcanic intrusion, synchronous with postvolcanic deformation in faults and shear zones, or some combination of superposed events over time. The gold deposits are distributed as clusters along linear belt-parallel fault zones internal to greenstone belts but show no association with major terrane boundary faults. World-class gold districts are associated with the thickest, internal parts of the greenstone belts identified by stratigraphic preservation and low metamorphic grades. Ore-proximal faults in those regions are more commonly associated with syn- and postvolcanic structures related to greenstone construction and deformation rather than major terrane amalgamation. Using the Kalgoorlie district as a template, the gold deposits show a predictable regional association with thicker greenstone rocks overlain unconformably by coarse clastic rock sequences in the uppermost units of the greenstone stratigraphy. At a camp scale, major gold deposits show a spatial association with unconformable epiclastic and volcaniclastic rocks located above an unconformity internal to the Black Flag Group. Distinct episodes of gold deposition in coincident locations suggest fundamental crustal structural controls provided by the fault architecture. Late penetrative deformation and metamorphism overprinted the greenstone rocks and the older components of many gold deposits and were accompanied by major gold deposition in late quartz-carbonate veins localized in crustal shear zones or their higher order fault splays.


2014 ◽  
Vol 26 (3-4) ◽  
pp. 816-833 ◽  
Author(s):  
Vadim G. Khomich ◽  
Natalia G. Boriskina ◽  
M. Santosh
Keyword(s):  

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