Paleomagnetism of gabbros of the Early Proterozoic Blachford Lake Intrusive Suite and the Easter Island dyke, Great Slave Lake, NWT: Possible evidence for the earliest continental drift

1984 ◽  
Vol 7 (1) ◽  
pp. 1-25 ◽  
Author(s):  
E. Irving ◽  
A. Davidson ◽  
J. C. McGlynn
Keyword(s):  
Continental Drift ◽  
Easter Island ◽  
Early Proterozoic ◽  
Great Slave Lake ◽  
Intrusive Suite

Geology and petrochemistry of lower Aphebian (2.4–2.0 Ga) alkaline plutonic and hypabyssal rocks in the East Arm of Great Slave Lake, Northwest Territories

1979 ◽  
Vol 16 (1) ◽  
pp. 60-72 ◽  
Author(s):  
J. P. N. Badham
Keyword(s):  
Northwest Territories ◽  
Field Data ◽  
Easter Island ◽  
Chemical Data ◽  
Lower Proterozoic ◽  
Great Slave Lake ◽  
Data Support ◽  
Igneous Complexes ◽  
Igneous Activity ◽  
History Of

Two alkaline igneous complexes and three lines of diatreme breccias were emplaced in the East Arm of Great Slave Lake during the lower Proterozoic. Field relationships suggest that those rocks are broadly cogenetic and were emplaced about 2.1 Ga ago.One of the intrusions, the Easter Island dyke, was rotated subsequent to emplacement such that both top and bottom are now exposed. Field and petrographic data are indicative of progressive differentiation along (i.e., up) the dyke and are substantiated by chemical data. The differentiation history of the early gabbros of the Blachford Lake complex is similar. Late differentiates of both complexes closely resemble the igneous matrices of the breccias and petrographic and chemical data support the proposal of cogenesis and contemporaneity.The field data show that there was a period of significant faulting and concomitant alkaline igneous activity in the East Arm area in the lower Proterozoic.

U–Pb zircon ages from Athapuscow aulacogen, East Arm of Great Slave Lake, N.W.T., Canada

1984 ◽  
Vol 21 (11) ◽  
pp. 1315-1324 ◽  
Author(s):  
S. A. Bowring ◽  
W. R. Van Schmus ◽  
P. F. Hoffman
Keyword(s):  
Slave Craton ◽  
Great Slave Lake ◽  
Intrusive Rocks ◽  
Island Group ◽  
Minimum Age ◽  
Great Bear Magmatic Zone ◽  
Intracratonic Basin ◽  
Two Phases ◽  
Intrusive Suite ◽  
Stratigraphic Sequences

Athapuscow aulacogen is an Early Proterozoic intracratonic basin located in the East Arm of Great Slave Lake between the Slave and northwest Churchill provinces. Athapuscow aulacogen comprises three stratigraphic sequences, the Wilson Island Group, the Great Slave Supergroup, and the Et-Then Group. New U–Pb zircon ages provide constraints on the development of the aulacogen.The Blachford Lake Intrusive Suite consists of an older alkaline phase (Hearne Channel Granite) dated at 2175 ± 7 Ma and a younger peralkaline phase (Thor Lake Syenite) dated at 2094 ± 10 Ma, confirming the suggestion that the two phases may not be related. A felsite from the Wilson Island Group has an age of 1928 ± 11 Ma. The Wilson Island Group is intruded by epizonal granites (Butte Island Intrusive Suite), one of which has an age of 1895 ± 8 Ma. The Wilson Island Group and the Butte Island Instrusive Suite are entirely allochthonous with respect to the Slave craton. Rocks of the Great Slave Supergroup overlie mylonitized Wilson Island Group rocks and both were involved in northeast-directed thrusting. The Compton laccoliths intrude rocks of the Great Slave Supergroup, postdate thrusting, and are about 1865 Ma old.The Blachford Lake Intrusive Suite is significantly older than both the rift sequence in Wopmay Orogen (ca. 1900 Ma) and the Wilson Island Group; it probably is genetically unrelated. The age of the Wilson Island Group and Butte Island Intrusive Suite is considerably younger than previous estimates and is close to the minimum age of rifting in Wopmay Orogen. The Compton laccoliths are very similar to intrusive rocks in the Great Bear Magmatic Zone of Wopmay Orogen and may be related to east-dipping subduction beneath the aulacogen.The new ages strengthen the correlations between Athapuscow aulacogen and Wopmay Orogen and suggest a link with events in the Trans-Hudson Orogen to the south.

Great Slave Lake shear zone, NW Canada : mylonitic record of Early Proterozoic continental convergence, collision and indentation

1992 ◽  
Vol 14 (7) ◽  
pp. 757-773 ◽  
Author(s):  
Simon Hanmer ◽  
Samuel Bowring ◽  
Otto van Breemen ◽  
Randall Parrish
Keyword(s):  
Shear Zone ◽  
Early Proterozoic ◽  
Great Slave Lake

Continental Drift

2016 ◽  
Author(s):  
Benjamin Grob-Fitzgibbon
Keyword(s):  
Continental Drift
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