| Title | Reactivated fault systems and their effects on outcrop patterns of thin-skinned early thrust imbrications in the Kiggavik uranium camp, Nunavut |
| Download | Downloads |
| Author | Anand, A; Jefferson, C W |
| Source | Geological Survey of Canada, Open File 7895, 2017, 9 pages (1 sheet), https://doi.org/10.4095/302776 (Open Access) |
| Image |  |
| Year | 2017 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| Related | This publication is related to Anand, A; Jefferson, C W;
(2017). Outcropping and remotely predicted lineaments, faults, fractures, and dykes in the Kiggavik uranium camp, Nunavut, Geological Survey of Canada, Open File 7896 |
| File format | readme
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| File format | pdf; rtf |
| Province | Nunavut |
| NTS | 66A/03; 66A/04; 66A/05; 66A/06; 66A/07; 66A/10; 66A/11; 66A/12; 66B/01; 66B/02; 66B/07; 66B/08; 66B/09 |
| Area | Judge Sissons Lake; Siamese Lake; Square Lake; Schultz Lake; Andrew Lake |
| Lat/Long WENS | -99.0000 -96.7500 64.8333 64.1667 |
| Subjects | economic geology; structural geology; tectonics; mineral deposits; uranium; ore mineral genesis; geological history; tectonic history; basin evolution; faulting; metamorphism; magmatism; deformation;
depositional history; alteration; structural analyses; structural features; faults; fractures; horsts; folds; antiforms; synforms; shear zones; lineaments; foliation; gneissosity; imbrication; hydrothermal systems; fluid flow; shear stress; stress
analyses; stress orientation; shear fractures; models; bedding planes; dykes; trend surface analyses; correlations; unconformities; discontinuities; fabric analysis; bedrock geology; lithology; iron formations; Kiggavik uranium camp; Thelon Basin;
Thelon Fault Zone; Judge Sissons Fault Zone; Schultz Lake Intrusive Complex (SLIC); Pukiq Lake Formation; Snow Island Suite; Ketyet River Group; Pipedream Assemblage; Woodburn Lake Group; Granite Thrust; Barrensland Group; Thelon Formation; Kivalliq
Igneous Suite; McRae Lake Diabase; Thelon River Diabase; Nueltin Granite; Wharton Ggroup; Amarook Formation; Pitz Formation; Hudson Suite; Hudson Granite Suite; Martell Syenite; Judge Sissons Pluton; Marjorie Hills Assemblage; Amaruulik Assembalge;
Half Way Hills Assemblavge; Mackenzie Igneous Event; Mackenzie Dyke Swarm; Ridge Fault; Pump Lake Fault; Skinny Lake Gorst; Long Lake Horst; Riedel shear stress models; dyke swarms; banded iron formations (BIF); Phanerozoic; Paleozoic; Ordovician;
Precambrian; Proterozoic |
| Illustrations | geoscientific sketch maps; rose diagrams; geochronological charts; cross-sections, structural; schematic representations; sketches; photographs |
| Program | South Rae Province Bedrock/Surficial geology, GEM2: Geo-mapping for Energy and Minerals |
| Released | 2017 07 17 |
| Abstract | Reactivated ENE-WSW-trending dextral fault arrays in the northeast Thelon Basin region are exemplified by the dextral, north-down, oblique-slip Thelon and Judge Sissons faults. We compiled and
interpreted a variety of geoscience data, including lineaments, detailed outcrop and samples to produce new maps that incorporate past observations by Industry and academic studies. The reactivated fault arrays discordantly transect the main basement
foliation and comprise zones of sub-parallel brittle and ductile fractures detailed here and interpreted as products of Riedel shear systems that were successively reactivated by multiple tectonic events with varying principle stresses.
The key
basement assemblage dismembered by the fault systems is a thrust- and fold-imbricated complex (hereafter "imbricate complex") com-prising 2.6 Ga epiclastic rocks and rhyolite of the Pukiq Lake formation (Snow Island Suite), and Paleoproterozoic
quartzite of the Ketyet River group. The imbricate complex structurally overlies and may include some metagreywacke of the Neoarchean Pipedream assemblage, Woodburn Lake group, from west of Judge Sissons Lake to southeastern Schultz Lake, trending
through the Andrew Lake, End, Granite Grid, Bong and Kiggavik uranium deposits. It lies between two inferred low-angle structures: Granite Thrust to the W and the Pukiq discontinuity to the SE. These are in turn offset by the Thelon and Judge Sissons
faults. Imbrication took place during DP1. The much younger Thelon Basin developed trans-extensionally during DP6-DP7 (Table 1).
Intersections between reactivated brittle-ductile fractures and the imbricate complex likely created conduits and
barriers to hydrothermal fluid flow forming basement-hosted uranium deposits during and/or after filling of Thelon Basin, similar to those of the Athabasca Basin. |
| Summary | (Plain Language Summary, not published)
Intersecting faults in the northeast Thelon Basin region were investigated under the Geomapping for Energy and Minerals Program in order to understand
their effects on outcrop patterns, and their potential spatial relationships to uranium (U) deposits. We compiled and interpreted existing and new data to produce maps that respect all observations. An important structural complex that existed long
before the reactivated faults and filling of the Thelon Basin is a stack of repeated a) greywacke, b) rhyolite and c) quartzite that overlies a number of uranium deposits and prospects. This near-horizontal stack was broken into small segments by
intersecting near-vertical reactivated faults, resulting in discontinuous outcrops that line up poorly. The stack formed an impermeable layer but the cross cutting faults, especially their intersections, created zones down which hot water could have
easily flowed to produce the deep accumulations of U oxide minerals. |
| GEOSCAN ID | 302776 |
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