The timing of prograde metamorphism in the Pontiac Subprovince, Superior craton; implications for Archean geodynamics and gold mineralization

2019 ◽  
Vol 320 ◽  
pp. 111-136 ◽  
Author(s):  
Nicolas Piette-Lauzière ◽  
Carl Guilmette ◽  
Audrey Bouvier ◽  
Stéphane Perrouty ◽  
Pierre Pilote ◽  
...  
Author(s):  
François Turlin ◽  
Stéphane De Souza ◽  
Michel Jébrak ◽  
Pierre-Arthur Groulier ◽  
Jordi Turcotte

The Archean Cheechoo stockwork gold deposit is hosted by a felsic intrusion of tonalitic-granodioritic composition and crosscutting pegmatite dikes in the Eeyou Istchee James Bay area of Quebec, Canada (Archean Superior craton). The evolution of the stockwork is characterized herein using field relationships, vein density, and connectivity measurements on drill core and outcrop zones. The statistical distribution of gold is used to highlight mechanisms of stockwork emplacement and gold mineralization and remobilization. Two statistical populations of gold concentration are present. Population A is represented by gold grades below 1 g/t with a lognormal cumulative frequency. It is widespread in the hydrothermally altered (albite and quartz) and mineralized facies of the pluton. It is controlled by the development of quartz-feldspar-diopside veins as shown by the similar lognormal distribution of grades and vein density and by the correspondence of grades with network connectivity. Diopside and actinolite porphyroblasts in deformed veins within sodic and calcsilicate alteration zones are evidence for auriferous vein emplacement prior to the amphibolite facies peak of metamorphism. Population B (>1 g/t) is erratic and exhibits a strong nugget effect. It is present throughout the mineralized portion of the pluton and in pegmatites. This population is interpreted as the result of gold remobilization during prograde metamorphism and pegmatite emplacement following the metamorphic peak. The pegmatites are interpreted to have scavenged gold emplaced prior to peak metamorphism. These results show the isotropic behavior of the investigated stockwork during regional deformation and its development during the early stages of regional prograde metamorphism.


PROMINE ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 1-11
Author(s):  
Retno Anjarwati ◽  
Arifudin Idrus ◽  
Lucas Donny Setijadji

The regional tectonic conditions of the KSK Contract of Work are located in the mid-Tertiary magmatic arc (Carlile and Mitchell, 1994) which host a number of epithermal gold deposits (eg, Kelian, Indon, Muro) and significant prospects such as Muyup, Masupa Ria, Gunung Mas and Mirah. Copper-gold mineralization in the KSK Contract of Work is associated with a number of intrusions that have occupied the shallow-scale crust at the Mesozoic metamorphic intercellular junction to the south and continuously into the Lower Tertiary sediment toward the water. This intrusion is interpreted to be part of the Oligocene arc of Central Kalimantan (in Carlile and Mitchell 1994) Volcanic rocks and associated volcanoes are older than intrusions, possibly aged Cretaceous and exposed together with all three contacts (Carlile and Mitchell, 1994) some researchers contribute details about the geological and mineralogical background, and some papers for that are published for the Beruang Kanan region and beyond but no one can confirm the genesis type of the Beruang Kanan region The mineralization of the Beruang Kanan area is generally composed by high yields of epithermal sulphide mineralization. with Cu-Au mineralization This high epithermal sulphide deposition coats the upper part of the Cu-Au porphyry precipitate associated with mineralization processes that are generally controlled by the structure


2017 ◽  
Vol 39 (2) ◽  
pp. 8-18
Author(s):  
N. Lyzhachenkо ◽  
◽  
S. Bondarenko ◽  
S. Kurylо ◽  
V. Syоmkа ◽  
...  

2004 ◽  
Vol 47 (2-3) ◽  
pp. 247-258 ◽  
Author(s):  
János Földessy ◽  
Éva Seress-Hartai ◽  
Géza Szebényi
Keyword(s):  

2020 ◽  
Author(s):  
Chong Ma ◽  
◽  
Mostafa Naghizadeh ◽  
Ademola Adetunji ◽  
Rajesh Vayavur ◽  
...  
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document