Early Aphebian basaltic volcanism in the southern District of Keewatin, Northwest Territories

1976 ◽  
Vol 13 (7) ◽  
pp. 1003-1005 ◽  
Author(s):  
Roy V. Beavon

A thin formation of folded mafic flows resting unconformably on Archean basement is informally named the Spi Lake basalt. Stratigraphic, structural, and textural evidence suggests that these lavas were probably fed from a diabase dike swarm dated at 2250+ m.y. by the Geological Survey of Canada. The Spi Lake basalt is overlain by conglomerate that may represent the base of the Hurwitz Group.

1991 ◽  
Vol 28 (7) ◽  
pp. 1078-1095 ◽  
Author(s):  
Adrian F. Park ◽  
Steven Ralser

A structural study of the Early Proterozoic Hurwitz Group has been carried out in the Tavani area, approximately 80 km southwest of Rankin Inlet, District of Keewatin, Northwest Territories. The Hurwitz Group, in the Tavani area, consists of orthoquartzites of the Kinga Formation (Whiterock Lake Member) and quartz-feldspar arenites and litharenites of the Tavani Formation. More localized lithologies include siltstone, sandstones, breccia, and shales beneath the Whiterock Lake Member and conglomerate, shales, and shale-clast breccias within the Tavani Formation.Open, northeast-trending folds dominate the Hurwitz Group, although overturned folds and easterly trending structures are developed locally. Later northwest-trending faults complicate the northeast-trending structural pattern. Three structural domains are defined: north of the Wilson River, the Whiterock Syncline, and the Last Lake belt. The interrelationship of folding and faulting creates distinctive patterns in each domain, though overall, folding is demonstrated to be a local response to basement faulting, including reactivation of Archean structures. An overall north–south compressive regime is envisaged in which heterogeneities in the Archean basement are responsible for local peculiarities.


2020 ◽  
Author(s):  
Ashley Rudy ◽  
Steve Kokelj ◽  
Alice Wilson ◽  
Tim Ensom ◽  
Peter Morse ◽  
...  

<p>The Beaufort Delta region in Northwest Territories, Canada is one of the most rapidly warming areas on Earth. Permafrost thaw and climate change are major stressors on northern infrastructure, particularly in this region which hosts the highest density of Arctic communities and the longest road network constructed on ice-rich permafrost in Canada. The Dempster and Inuvik to Tuktoyaktuk Highways (ITH) comprise a 400-km corridor connecting the region with southern Canada. The corridor delivers a unique opportunity to develop a societally-relevant, northern-driven permafrost research network to encourage collaboration, and support pure and applied studies that engage stakeholders, encourage community participation, and acknowledge northern interests. Successful implementation requires leadership and institutional support from the Government of the Northwest Territories (GNWT) and Inuvialuit and Gwich’in Boards and landowners, and coordination between research organizations including NWT Geological Survey, Aurora Research Institute, Geological Survey of Canada, and universities to define key research priorities, human and financial resources to undertake studies, and protocols to manage data collection and reporting.</p><p>In 2017, a state of the art ground temperature monitoring network was established along the Dempster-ITH corridor by the GNWT in collaboration with Federal and Academic partners. This network in combination with the maintenance of the Dempster Highway and recent design and construction of the ITH, has created a national legacy of permafrost geotechnical, terrain and geohazard information in this region. The objectives of this program are to integrate old and new data to synthesize physiographic, hydrological, thermal, and geotechnical conditions along the corridor, and to develop applied permafrost research projects that support planning and maintenance of this critical northern infrastructure. In this presentation, we highlight: 1) a collaborative research framework that builds northern capacity and involves northerners in the generation of knowledge and its application to increase community based permafrost monitoring; 2) summaries of existing infrastructure datasets and their foundation for research; and 3) new projects that address emerging climate-driven infrastructure stressors. As the effects of climate change on permafrost environments, infrastructure and communities continue to increase, the need for northern scientific capacity and applied research to support informed decision-making, climate change adaptation and risk management will become increasingly critical. The development of resilient researcher-stakeholder-community relationships is also necessary for the scientific and research initiatives to reach their potential.</p><p> </p>


1975 ◽  
Vol 12 (1) ◽  
pp. 95-114 ◽  
Author(s):  
R. K. Wanless ◽  
K. E. Eade

Rb–Sr and U–Pb dating techniques have been utilized to identify and date Archean supracrustal rocks within the Churchill structural province in regions where K–Ar age determinations have recorded only the effects of younger Hudsonian orogeny. The age of emplacement of Archean granodiorite has been established at 2550 m.y., a determination that also provides a minimum age for volcanic rocks intruded by the granodiorite.The overlying Proterozoic Hurwitz Group volcanic rocks have been dated for the first time at 1808 ± 35 m.y. (Upper Aphebian). A post-Hurwitz Group quartz monzonite pluton intruded the granodiorite gneiss at 1772 ± 22 m.y. and the age of the post-tectonic Nueltin Lake Granite has been established at 1700 ± 16 m.y. (Paleohelikian).It is concluded that the Hurwitz Group cannot be correlated with the Huronian succession in Ontario as the Hurwitz Group rocks are 300 to 400 m.y. younger than the Huronian strata.


1991 ◽  
Vol 28 (11) ◽  
pp. 1863-1872 ◽  
Author(s):  
Judith G. Patterson

A succession of mafic flows intercalated with sandstone and overlain by conglomerate, herein named the Spi Group, lies unconformably on Archean basement and is preserved in a syncline near Spi Lake, N.W.T. An alluvial fan setting near active rift fault escarpments is the interpreted environment of deposition. The nearby Montgomery Lake Group, Mackenzie Lake metasediments, and Padlei Formation at the base of the Hurwitz Group are possible correlatives of the Spi Group; diabase dykes of the Kaminak swarm, common in the Archean basement, are possibly related to the mafic flows. Correlation with the upper, coarse clastic part of the Hurwitz Group (Tavani Formation) is discounted because the Spi conglomerate does not contain clasts of Hurwitz lithology. The Montgomery Lake, Padlei and Spi successions are interpreted as being rift-related, and are older than the 2.1 Ga gabbro that intrudes the Hurwitz Group. Recognition of widespread rifting in this part of the Hearne Province constrains tectonic modelling of the preorogenic history of the Trans-Hudson hinterland.


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