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Background
Work along the Rivière aux Feuilles in Quebec (Percival and Card, 1994), and in three areas farther north (Percival et al., 1995, 1996, 1997) allowed Percival et al. (1992, 2001) to recognize a series of distinct geological and geophysical domains within the Minto Subprovince based on lithological, structural and aeromagnetic differences. Between 1997 and 2003, the work carried out by the Government of Québec under the Far North Program clarified the nature and boundaries of these areas. This work highlighted seven domains and two terranes within the Minto Subprovince.
Description
The Utsalik Domain is part of the Arnaud River Terrane and occupies the NE portion of the Minto Subprobvince. It is limited to the west and south by the Utsalik Domain, to the est by the Labrador Trough and the Diana Complex, and to the north by the Ungava Trough.
Geology
The Douglas Harbour Domain is characterized by a large unit of tonalitic rock (Faribault-Thury Suite; 2785-2775 Ma), which contains many klippes of volcano-sedimentary rocks (Arnaud Complex) related to various magmatic events. Some of these klippes have ages comparable to volcano-sedimentary sequences of the La Grande Subprovince (2.88-2.87 Ga; Gayot Complex). The Douglas Harbour Domain is also distinguished by the presence of two large ovoid massifs of charnockitic rocks (Troie and Qimussinguat complexes; 2740-2722 Ma) corresponding to two positive aeromagnetic anomalies with variegated patterns. These anomalies contrast with the magnetic low associated with tonalitic and sedimentary rocks of this domain. Rocks of the northern part of the Douglas Harbour Domain are cut by granitic to monzonitic intrusions (Leridon Suite) aged between 2735 and 2720 Ma. Rocks of the southern part of the domain are also cut by porphyraceous monzonite and monzodiorite intrusions (Belloy Suite; 2690 Ma). The western edge of the Douglas Harbour Domain corresponds to ductile deformation zones and contains small nepheline syenite plutons (Kimber Suite; 2760 Ma). Rocks in the northern part of Douglas Harbour Domain have model ages indicating that they were formed from a juvenile source (TDM <2.9 Ga). In contrast, rocks of the Troie Complex have an older isotopic signature (3.1-3.0 Ga) that indicates interaction with evolved bedrock (Leclair, 2008).
References
Publications available through Sigéom Examine
LECLAIR, A. 2008. CONTEXTE GÉOLOGIQUE RÉGIONAL DU NORD-EST DE LA PROVINCE DU SUPÉRIEUR. DANS : SYNTHESE DU NORD-EST DE LA PROVINCE DU SUPERIEUR. MRNF. MM 2008-02, 198 pages and 8 plans.
Other publications
Percival, J.A., Card, K.D. 1994. Geology, Lac Minto-Rivière aux Feuilles, Québec. Geological Survey of Canada, « A » Series Map 1854A, 1994, 1 sheet. doi:10.4095/194490
Percival, J.A., Mortensen, J.K., Stern, R.A., Card, K.D., Bégin, N.J. 1992. Giant granulite terranes of northeastern Superior Province: the Ashuanipi complex and Minto block. Canadian Journal of Earth Sciences; volume 29, pages 2287-2308. doi:10.1139/e92-179
Percival, J.A., Skulski, T., Card, K.D., Lin, S. 1995. Geology, Rivière Kogaluc-Lac Qalluviartuuq region (parts of 34J and 34-O), Quebec. Geological Survey of Canada, Open File 3112, 1 sheet. doi:10.4095/205269
Percival, J.A., Skulski, T., Nadeau, L. 1996. Geology, Lac Couture, Quebec. Geological Survey of Canada, Open File 3315, 1 sheet. doi:10.4095/208195
Percival, J.A., Skulski, T., Nadeau, L. 1997. Reconnaissance geology of the Pelican-Nantais Belt, northeastern Superior Province. Geological Survey of Canada, Open File 3525, 1 sheet. doi:10.4095/209271
Percival, J.A., Stern, R.A., Skulski, T. 2001. Crustal growth through successive arc magmatism: reconnaissance U–Pb SHRIMP data from the northeastern Superior Province, Canada. Precambrian Research; volume 109, pages 203-238. doi:10.1016/S0301-9268(01)00148-6