| Title | Geophysical reassessment of the role of ancient lineaments on the development of the western margin of Laurentia and its sediment-hosted Zn-Pb deposits, Yukon and Northwest Territories |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Hayward, N ;
Paradis, S |
| Source | Geological Survey of Canada, Scientific Presentation 137, 2022, 4 pages (1 sheet), https://doi.org/10.4095/330038  Open Access |
| Image |  |
| Year | 2022 |
| Publisher | Natural Resources Canada |
| Document | serial |
| Lang. | English |
| Media | digital; on-line |
| Related | This publication is related to Geophysical reassessment of
the role of ancient lineaments on the development of the western Laurentian margin and its sediment-hosted Zn-Pb deposits, Yukon and Northwest Territories, Canada |
| File format | pdf |
| Province | Yukon; Northwest Territories; British Columbia; Nunavut; Alberta |
| NTS | 84L; 84M; 85C; 85D; 85E; 85F; 85J; 85K; 85L; 85M; 85N; 85O; 86A; 86B; 86C; 86D; 86E; 86F; 86G; 86H; 86I; 86J; 86K; 86L; 86M; 94I; 94J; 94K; 94L; 94M; 94N; 94O; 94P; 95; 96; 97B; 104I; 104J; 104K; 104M; 104N;
104O; 104P; 105; 106; 107A; 107B; 114; 115; 116; 117A; 117B |
| Lat/Long WENS | -141.0000 -112.0000 69.0000 58.0000 |
| Subjects | economic geology; structural geology; geophysics; Science and Technology; Nature and Environment; mineral deposits; sedimentary ore deposits; lead; zinc; ore mineral genesis; mineralization; ore
controls; structural controls; bedrock geology; structural features; lineaments; faults; faults, thrust; lithology; sedimentary rocks; clastics; geophysical surveys; aeromagnetic surveys; gravity surveys; geophysical interpretations; gravity
interpretations; gravity anomalies; bouguer gravity; magnetic interpretations; magnetic anomalies; structural trends; crustal structure; crustal thickness; tectonic setting; tectonic history; craton; sedimentary basins; basin evolution; terranes;
accretion; faulting; magmatism; intrusions; decollement; models; modelling; mineral occurrences; Laurentia; Laurentian Margin; North American Craton; Selwyn Basin; Canadian Cordillera; Liard Line; Fort Norman Structure; Leith Ridge Fault; Macdonald
Platform; Mackenzie River Lineament; Mackenzie Mountains Fold and Thrust Belt; Misty Creek Embayment; Mackenzie Mountains Supergroup; Windermere Supergroup; Data processing |
| Illustrations | geoscientific sketch maps; models; cross-sections |
| Program | GEM-GeoNorth: Geo-mapping for Energy and Minerals GEM Program Coordination |
| Released | 2022 06 01 |
| Abstract | The role of crustal lineaments in the development of the western margin of Laurentia, Selwyn basin and associated sediment-hosted Zn-Pb deposits (clastic-dominated, Mississippi-Valley-type) in Yukon and
NWT, are reassessed through a new 3-D inversion strategy applied to new compilations of gravity and magnetic data. Regionally continuous, broadly NE-trending crustal lineaments including the Liard line, Fort Norman structure, and Leith Ridge fault,
were interpreted as having had long-standing influence on craton, margin, and sedimentary basin development. However, multiple tectonic overprints including terrane accretion, thrust faulting, and plutonism obscure the region's history.
The Liard
line, related to a transfer fault that bounds the Macdonald Platform promontory, is refined from the integration of the new geophysical models with published geological data. The geophysical models support the continuity of the Fort Norman structure
below the Selwyn basin, but the presence of Leith Ridge fault is not supported in this area. The ENE-trending Mackenzie River lineament, traced from the Misty Creek Embayment to Great Bear Lake, is interpreted to mark the southern edge of a cratonic
promontory. The North American craton is bounded by a NW-trending lineament interpreted as a crustal manifestation of lithospheric thinning of the Laurentian margin, as echoed by a change in the depth of the lithosphere-asthenosphere boundary. The
structure is straddled by Mississippi Valley-type Zn-Pb occurrences, following their palinspastic restoration, and also defines the eastern limit of mid-Late Cretaceous granitic intrusions. Another NW-trending lineament, interpreted to be associated
with a shallowing of lower crustal rocks, is coincident with clastic-dominated Zn-Pb occurrences. |
| Summary | (Plain Language Summary, not published)
New strategies are applied to gravity and magnetic data in order to create three-dimension models of the crust of the northern Canadian Cordillera of
Yukon and the Northwest Territories. The models are used to update the interpretation of the structure and development of the ancient edge of western North American (Laurentia) and its overlying sedimentary basin (Selwyn basin), and to investigate
potential relationships to mineral deposits hosted within sedimentary rocks of the basin. The locations of previously proposed faults are refined and new faults identified. The faults are shown to have influenced the development of the western edge
of Laurentia and to be spatially related to mineral deposits. |
| GEOSCAN ID | 330038 |
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