An interim report on geological, structural, and geochronological investigations of granitoid rocks in the vicinity of the Swayze greenstone belt, southern Superior Province, Ontario

1994 ◽  
Author(s):  
K B Heather ◽  
O van Breemen
Keyword(s):  
Greenstone Belt ◽  
Superior Province ◽  
Interim Report ◽  
Granitoid Rocks

U–Pb zircon ages for rocks from the Island Lake greenstone belt, Manitoba

1986 ◽  
Vol 23 (1) ◽  
pp. 92-101 ◽  
Author(s):  
A. Turek ◽  
T. M. Carson ◽  
Patrick E. Smith ◽  
W. R. Van Schmus ◽  
W. Weber
Keyword(s):  
Greenstone Belt ◽  
Quartz Diorite ◽  
Superior Province ◽  
Intrusive Complex ◽  
Quartz Porphyry ◽  
Zircon Age ◽  
Metasedimentary Rocks ◽  
Intrusive Rocks ◽  
Granitoid Rocks

The Archean Hayes River Group of the Island Lake greenstone belt (Superior Province, Sachigo Subprovince) comprises mafic to felsic metavolcanics, subvolcanics, and associated metasedimentary rocks. The Hayes River Group is intruded by granitoid rocks belonging to the early intrusive complex. One such pluton, the Bella Lake tonalite, is intrusive into the metabasalt of the Hayes River Group and has a U–Pb zircon age of 2886 ± 15 Ma. Similar intrusives of this complex, either internal or marginal to the greenstone belt, yield zircon ages of 2801 ± 8 Ma (Pipe Point tonalit) and 2768 ± 22 Ma (Linklater Island prophyry). This suggests that the early intrusive complex was emplaced over an ~ 120 Ma long interval by at least three separate intrusive episodes.Subsequent to the emplacement of the early intrusive complex, the isoclinally folded Hayes River Group and the early intrusive complex were uplifted, eroded, and followed by the unconformable deposition of the Island Lake Group, comprising fluvial to marine metasedimentary rocks. The stratigraphically lower part of the Island Lake Group is bracketed by the 2768 ± 22 Ma age of the Linklater Island porphyry and the 2729 ± 3 Ma age obtained for the late tectonic suite—the Pipe Point quartz diorite and feldspar porphyry. A feldspar quartz porphyry belonging to the post-tectonic intrusive rocks intrudes higher stratigraphic levels and has been dated at 2699 ± 4 Ma (Horseshoe Island quartz feldspar porphyry).

Rubidium–strontium ages from the Oxford Lake – Knee Lake greenstone belt, northern Manitoba

1980 ◽  
Vol 17 (5) ◽  
pp. 560-568 ◽  
Author(s):  
G. S. Clark ◽  
S.-P. Cheung
Keyword(s):  
Greenstone Belt ◽  
Volcanic Rocks ◽  
Superior Province ◽  
Granitic Intrusion ◽  
Greenstone Belts ◽  
Archean Greenstone Belts

Rb–Sr whole-rock ages have been determined for rocks from the Oxford Lake – Knee Lake – Gods Lake greenstone belt, in the Superior Province of northeastern Manitoba.The age of the Magill Lake Pluton is 2455 ± 35 Ma (λ87Rb = 1.42 × 10−11 yr−1), with an initial 87Sr/86Sr ratio of 0.7078 ± 0.0043. This granitic stock intrudes the Oxford Lake Group, so it is post-tectonic and probably related to the second, weaker stage of metamorphism.The age of the Bayly Lake Pluton is 2424 ± 74 Ma, with an initial 87Sr/86Sr ratio of 0.7029 ± 0.0001. This granodioritic batholith complex does not intrude the Oxford Lake Group. It is syn-tectonic and metamorphosed.The age of volcanic rocks of the Hayes River Group, from Goose Lake (30 km south of Gods Lake Narrows), is 2680 ± 125 Ma, with an initial 87Sr/86Sr ratio of 0.7014 ± 0.0009.The age for the Magill Lake and Bayly Lake Plutons can be interpreted as the minimum ages of granitic intrusion in the area.The age for the Hayes River Group volcanic rocks is consistent with Rb–Sr ages of volcanic rocks from other Archean greenstone belts within the northwestern Superior Province.

scholarly journals Geology, Red Lake greenstone belt, western Superior Province, Ontario

2004 ◽  
Author(s):  
M Sanborn-Barrie ◽  
T Skulski ◽  
J Parker
Keyword(s):  
Greenstone Belt ◽  
Superior Province ◽  
Red Lake

scholarly journals Geology, Sturgeon Lake greenstone belt, western Superior Province, Ontario

2005 ◽  
Author(s):  
M Sanborn-Barrie ◽  
T Skulski
Keyword(s):  
Greenstone Belt ◽  
Superior Province

Geological evolution of the Manitouwadge greenstone belt and Wawa-Quetico subprovince boundary, Superior Province, Ontario, constrained by U-Pb zircon dates of supracrustal and plutonic rocks

1999 ◽  
Vol 36 (6) ◽  
pp. 945-966 ◽  
Author(s):  
Eva Zaleski ◽  
Otto van Breemen ◽  
Virginia L Peterson
Keyword(s):  
Hydrothermal Alteration ◽  
Greenstone Belt ◽  
Boundary Region ◽  
Detrital Zircons ◽  
Ductile Deformation ◽  
Superior Province ◽  
Geological Evolution ◽  
Hydrothermal Alteration Zones ◽  
Depositional Age ◽  
East West

Fifty million years of Archean evolution is recorded in the Manitouwadge greenstone belt and the Wawa-Quetico boundary region, from ca. 2720 Ma volcanism and subvolcanic plutonism associated with massive sulphide deposits and hydrothermal alteration zones, to 2689-2687 Ma and 2680-2677 Ma synkinematic plutonism. In the greenstone belt, greywackes were deposited after 2693 Ma, post-dating local volcanism by at least 25 Ma, and requiring that the volcanic-sedimentary contact is an unconformity or a fault. In migmatitic greywackes in the Quetico subprovince, detrital zircons limit the depositional age to <2690 Ma, permitting correlation of greywackes across the Wawa-Quetico subprovince boundary. Upward-facing inclined F2 folds that deform the volcanic-sedimentary contact are bracketed by the 2687 ± 2 Ma Loken Lake pluton, which shows strong D2 fabrics, and by 2680+4-3 Ma foliated granite which cuts D2 fabrics. Dextral transpression producing regional F3 folds and the overall east-west trends of the Wawa-Quetico boundary region post-dated the 2680 ± 2 Ma Nama Creek pluton. Field relationships and isotopic ages support correlation of greywackes across the subprovince boundary, and demonstrate that most or all of the ductile deformation post-dated sedimentation. Ductile structures, especially those associated with dextral transpression, are not directly related to juxtaposition of the Wawa and Quetico subprovinces, as these were already contiguous, either through sedimentation on a volcanic substrate or as a result of earlier cryptic structures. Our results imply that the belt-like configuration of the subprovinces, emphasized in accretionary models of the Superior Province, is a relatively late feature that overprints older, tectonically significant structures.

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