Alteration Facies Linkages Among Iron Oxide Copper-Gold, Iron Oxide-Apatite, and Affiliated Deposits in the Great Bear Magmatic Zone, Northwest Territories, Canada

2016 ◽  
Vol 111 (8) ◽  
pp. 2045-2072 ◽  
Author(s):  
L. Corriveau ◽  
J.-F. Montreuil ◽  
E. G. Potter
Keyword(s):  
Iron Oxide ◽  
Northwest Territories ◽  
Copper Gold ◽  
Great Bear Magmatic Zone

Fault reconstructions using aeromagnetic data in the Great Bear magmatic zone, Northwest Territories, Canada

2014 ◽  
Vol 51 (10) ◽  
pp. 927-942 ◽  
Author(s):  
Nathan Hayward ◽  
Louise Corriveau
Keyword(s):  
Iron Oxide ◽  
Vertical Axis ◽  
Fault System ◽  
Aeromagnetic Data ◽  
Block Rotation ◽  
Magmatic Arc ◽  
The North ◽  
Copper Gold ◽  
Great Bear Magmatic Zone ◽  
Transcurrent Faults

The Great Bear magmatic zone, located in Wopmay orogen, is a 1.875–1.84 Ga belt, 450 km long by 100 km wide of volcanic and allied plutonic rocks interpreted as a Paleoproterozoic magmatic arc. The belt, which contains economically important mineralization, was folded and subsequently cut by a swarm of northeast-striking transcurrent faults, which are part of a regional conjugate fault system interpreted to result from terminal collision of the Nahanni – Fort Simpson terrane. Fault reconstructions based on the interpretation of aeromagnetic data and geological maps provide first-order models of deformation mechanisms associated with, and the configuration of the Great Bear magmatic zone prior to, its dissection by northeast-striking transcurrent faults. The models show that vertical axis block rotation (plane strain) of ∼4.5° can explain fault offsets in the south, but that greater rotation is required to explain many of the displacements in the north. However, offsets on transcurrent faults that border the Camsell River district are greater than can be explained by vertical axis block rotation model alone and may include a component of Mesoproterozoic contractional deformation associated with the Racklan–Forward orogeny. Following reconstruction, iron oxide alkali alteration and associated mineralization, which pre-date transcurrent faulting, form a pair of northerly trending zones on the east and west margins of the belt. We suggest that these zones, whose exposure is related to broad synclinal folding of some of the oldest rocks in the Great Bear magmatic zone, are where iron oxide copper–gold (IOCG)-targeted exploration efforts should be focused on these areas in both outcrop and subcrop.

scholarly journals A Paleoproterozoic Andean-type iron oxide copper-gold environment, the Great Bear magmatic zone, Northwest Canada

2017 ◽  
Vol 81 ◽  
pp. 123-139 ◽  
Author(s):  
Luke Ootes ◽  
David Snyder ◽  
William J. Davis ◽  
Pedro Acosta-Góngora ◽  
Louise Corriveau ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Copper Gold ◽  
Great Bear Magmatic Zone ◽  
Andean Type

scholarly journals Paleoproterozoic Iron Oxide Apatite (IOA) and Iron Oxide-Copper-Gold (IOCG) mineralization in the East Arm Basin, Northwest Territories, Canada

2020 ◽  
Vol 57 (1) ◽  
pp. 167-183
Author(s):  
E.G. Potter ◽  
L. Corriveau ◽  
B.A. Kjarsgaard
Keyword(s):  
Iron Oxide ◽  
Direct Relationship ◽  
Regional Analysis ◽  
Volcanic Rocks ◽  
Intermediate Composition ◽  
Iocg Deposits ◽  
Copper Gold ◽  
Great Bear Magmatic Zone ◽  
Host Rocks ◽  
Fault Breccia

The Paleoproterozoic East Arm Basin of Canada hosts polymetallic vein, iron oxide–apatite (IOA), and potential iron oxide–copper–gold (IOCG) mineral occurrences, mainly associated with a belt of ca. 1.87 Ga intermediate-composition sills termed the Compton intrusions. Advances in our knowledge of the East Arm Basin and of IOA and IOCG deposits within the broader context of iron oxide and alkali-calcic alteration systems enables a new regional analysis of this mineralization and facilitates comparison of these mineral occurrences and host rocks to the nearby Great Bear magmatic zone IOCG districts. The Compton intrusions and co-magmatic Pearson Formation volcanic rocks are comparable in age and composition to intrusive plus volcanic rocks of the Great Bear magmatic zone that host IOA–IOCG mineralization. Taking into account fault displacements, emplacement of Compton intrusions and Pearson Formation volcanic rocks are also consistent with the architecture of modern arcs, supporting a direct relationship with the Great Bear subduction zone. Trace element patterns of uraninite contained in IOA occurrences of the East Arm Basin are also similar to the patterns of uraninite from the Great Bear magmatic zone occurrences, consistent with both regions having experienced similar iron oxide and alkali-calcic alteration and mineralization. Our new results indicate that exploration for IOA, IOCG, and affiliated deposits in the East Arm Basin should focus on delineating increased potassic-iron alteration types and fault/breccia zones associated with these systems through field mapping and application of geochemical, radiometric, magnetic, and gravity surveys.

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