| Title | Fault reconstructions using aeromagnetic data in the Great Bear magmatic zone, Northwest Territories, Canada |
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| Author | Hayward, N ;
Corriveau, L |
| Source | Canadian Journal of Earth Sciences vol. 51, no. 10, 2014 p. 927-942, https://doi.org/10.1139/cjes-2014-0035  Open Access |
| Image |  |
| Year | 2014 |
| Alt Series | Earth Sciences Sector, Contribution Series 20120218 |
| Publisher | Canadian Science Publishing |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Northwest Territories |
| NTS | 85M; 85N; 86E; 86L; 86K; 86F |
| Lat/Long WENS | -120.0000 -116.0000 67.0000 63.0000 |
| Subjects | structural geology; geophysics; structural analyses; structural features; faults; aeromagnetic surveys; aeromagnetic interpretation; Great Bear magmatic zone; Wopmay orogen |
| Illustrations | location maps; tables; plots |
| Program | GEM: Geo-mapping for Energy and Minerals Iron-oxide Copper-gold (IOCG) / Multiple Metals - Great Bear Lake (NWT) |
| Released | 2014 10 01 |
| Abstract | 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\'024.5° 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. |
| GEOSCAN ID | 291877 |
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