| Abstract: | The composition, chronology, and structural relations of the Saskatchewan Craton and enveloping mylonitic rocks exposed in basement windows of the Glennie Domain, Trans-Hudson Orogen, have been determined by geochemical, geochronologic, and structural studies accompanying detailed field mapping. Basement windows lie along the hinge zone of a regional crustal culmination and consist mostly of 2.4-2.5 Ga felsic plutonic rocks enveloped by the Nistowiak Thrust. The Nistowiak Thrust is a folded, 1-2 km thick, upper amphibolite facie??s mylonite zone formed during emplacement of the Flin Flon-Glennie Complex across the Saskatchewan Craton. It is likely correlative to the Pelican Thrust, which envelops basement windows in the Hanson Lake Block -100 km to the east. An internal high strain zone within the overlying nappe pile, the Guncoat Thrust, is composed primarily of mylonitized porphyroclastic pelitic and psammitic migmatites. U-Pb geochronological results suggest calc-alkaline plutonism from 1889-1837 Ma, thrust stacking, peak metamorphism and associated anatexis between 1837 and 1809 Ma, isotopic closure of titanite at 1790-1772 Ma, and intrusion of late granitic rocks at 1770-1762 Ma. This is in agreement with ages from the Hanson Lake Block, and La Ronge, Kisseynew, and Flin-Flon domains in Saskatchewan and Manitoba, and from the Ungava-Baffin portion of Trans-Hudson Orogen, suggesting broadly synchronous thermotectonic processes along a strike length of 2000 km. We speculate that the Saskatchewan Craton, rather than representing an exotic continental fragment, rifted from the Superior and/or Hearne Provinces at ca. 2.1 Ga and that the Trans-Hudson Orogen is an internal orogen. In this scenario the Maniwekan Ocean, developed between the Rae-Hearne and Superior cratons, opened and closed about similar pole(s) of plate motion. ?? 1998 by The University of Chicago. All rights reserved. |
| Genre: | Article |
| ProdID: | 70019726 |
| Citation Author: | Chiarenzelli, J.; Aspler, L.; Villeneuve, M.; Lewry, J. |
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| Citation End Page: | 267 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Geology |
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| Citation Number Of Pages: | 21 |
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| Citation Search Results Text: | Early proterozoic evolution of the saskatchewan craton and its allochthonous coyer, trans-hudson Orogen; 1998; Article; Journal; Journal of Geology; Chiarenzelli, J.; Aspler, L.; Villeneuve, M.; Lewry, J. |
| Citation Start Page: | 247 |
| Citation Volume: | 106 |
| Citation Year: | 1998 |
| Type: | citation/reference |
| Text: | Early proterozoic evolution of the saskatchewan craton and its allochthonous coyer, trans-hudson Orogen; 1998; Article; Journal; Journal of Geology; Chiarenzelli, J.; Aspler, L.; Villeneuve, M.; Lewry, J. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 1998 00:00 -0600 |
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