An oblique cross section of Archean continental crust at the northwestern margin of Superior Province, Manitoba, Canada

1990 ◽  
pp. 327-341 ◽  
Author(s):  
Werner Weber ◽  
Klaus Mezger
Keyword(s):  
Continental Crust ◽  
Cross Section ◽  
Superior Province ◽  
Northwestern Margin

The Pikwitonei Granulite Domain, Manitoba: a giant Neoarchean high-grade terrane in the northwest Superior ProvinceThis article is one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh.N. Machado, T.E. Krogh, and W. Weber are deceased.

2011 ◽  
Vol 48 (2) ◽  
pp. 205-245 ◽  
Author(s):  
L. M. Heaman ◽  
Ch. O. Böhm ◽  
N. Machado ◽  
T. E. Krogh ◽  
W. Weber ◽  
...  
Keyword(s):  
Granulite Facies ◽  
Superior Province ◽  
High Grade ◽  
Metamorphic Zircon ◽  
Special Issue ◽  
Metamorphic History ◽  
Zircon Growth ◽  
The World ◽  
Northwestern Margin ◽  
History Of

The Pikwitonei Granulite Domain located at the northwestern margin of the Superior Province is one of the largest Neoarchean high-grade terranes in the world, with well-preserved granulite metamorphic assemblages preserved in a variety of lithologies, including enderbite, opdalite, charnockite, and mafic granulite. U–Pb geochronology has been attempted to unravel the protolith ages and metamorphic history of numerous lithologies at three main localities; Natawahunan Lake, Sipiwesk Lake, and Cauchon Lake. The U–Pb age results indicate that some of the layered enderbite gneisses are Mesoarchean (3.4–3.0 Ga) and the more massive enderbites are Neoarchean. The high-grade metamorphic history of the Pikwitonei Granulite Domain is complex and multistage with at least four episodes of metamorphic zircon growth identified: (1) 2716.1 ± 3.8 Ma, (2) 2694.6 ± 0.6 Ma, (3) 2679.6 ± 0.9 Ma, and (4) 2642.5 ± 0.9 Ma. Metamorphic zircon growth during episodes 2 and 3 are interpreted to be regional in extent, corresponding to M1 amphibolite- and M2 granulite-facies events, respectively, consistent with previous field observations. The youngest metamorphic episode at 2642.5 Ma is only recognized at southern Cauchon Lake, where it coincides with granite melt production and possible development of a major northeast-trending deformation zone. The timing and multistage metamorphic history recorded in the Pikwitonei Granulite Domain is similar to most Superior Province high-grade terranes and marks a fundamental break in Archean crustal evolution worldwide at the termination of prolific global Neoarchean greenstone belt formation.

Multiple episodes of dike emplacement along the northwestern margin of the Superior Province, Manitoba

1994 ◽  
Vol 99 (B11) ◽  
pp. 21717-21732 ◽  
Author(s):  
Yongjian Zhai ◽  
Henry C. Halls ◽  
Martin P. Bates
Keyword(s):  
Superior Province ◽  
Northwestern Margin ◽  
Multiple Episodes

Restoration of the Caledonian Baltoscandian margin from balanced cross-sections: the problem of excess continental crust

1987 ◽  
Vol 78 (3) ◽  
pp. 197-217 ◽  
Author(s):  
R. A. Gayer ◽  
A. H. N. Rice ◽  
D. Roberts ◽  
C. Townsend ◽  
A. Welbon
Keyword(s):  
Continental Crust ◽  
Cross Section ◽  
Continental Margin ◽  
Cross Sections ◽  
Branch Line ◽  
Norwegian Coast ◽  
Thrust Sheets ◽  
Thrust System ◽  
Basement Ridge ◽  
The Baltic

ABSTRACTConsideration of six balanced cross-sections through parts of the Finnmark Caledonides, N Norway indicates that shortening varies between 25% and 75%. A restored long cross-section across the width of the orogen, constructed with the aid of a branch line map, demonstrates a foreland propagating thrust system, with earlier formed more internal metamorphic nappes thrust SE 330 km under ductile conditions and then carried piggyback ESE a further 296 km on later brittle thrust sheets. Total shortening is 78·7% with a translation of the most internal thrust sheet of 626 km.The restored section suggests that: (1) the rate of propagation of deformation from hinterland to foreland is c. 2·27 cm y−1; (2) incorporation of basement into the nappes resulted from inversion of extensional faults formed during Iapetus rifting; (3) during rifting a Finnmark basement ridge separated a 220 km wide southeasterly Gaissa basin from the passive Iapetus continental margin which was at least 423 km wide; (4) the Finnmark Caledonides resulted from a continent-microcontinent collision which obducted continental crust at least 600 km across the Baltic margin; and (5) the Caledonian Baltoscandian margin prior to Iapetus suturing extended at least 400 km W of the Norwegian coast. On a Bullard reconstruction this overlaps with Laurentian rocks in Greenland. The excess continental crust is accounted for by shortening of the Baltoscandian margin during collision.

Abstracts 1985 CSEG/CGU convention, August 1985, GEOPHYSICS (v. 50, p. 1361–1387).

Geophysics ◽  
1986 ◽  
Vol 51 (2) ◽  
pp. 525-525
Keyword(s):  
Cross Section ◽  
Superior Province

One abstract was inadvertently omitted from the CSEG/CGU abstracts section in the August 1985 issue of Geophysics (v. 50, p. 1361–1387). The abstract, which was presented at the Lithoprobe I session during the 1985 convention, May 7–10 in Calgary, appears below. We regret the oversight. Geophysical Properties of the Superior Province Crust Based on the Pikwitonei‐Cross Lake Crustal Cross‐Section

Intra-oceanic production of continental crust in a Th-depleted ca. 3.0�Ga arc complex, western Superior Province, Canada

2003 ◽  
Vol 146 (1) ◽  
pp. 78-99 ◽  
Author(s):  
Joseph B. Whalen ◽  
John A. Percival ◽  
Vicki J. McNicoll ◽  
Frederick J. Longstaffe
Keyword(s):  
Continental Crust ◽  
Superior Province

The Western Superior Province Lithoprobe and NATMAP transects: introduction and summary

2006 ◽  
Vol 43 (7) ◽  
pp. 743-747 ◽  
Author(s):  
John A Percival ◽  
Herwart Helmstaedt
Keyword(s):  
Continental Crust ◽  
Greenstone Belt ◽  
Wide Spectrum ◽  
Superior Province ◽  
Western Region ◽  
Research Projects ◽  
Special Issue ◽  
Multidisciplinary Research ◽  
Red Lake ◽  
History Of

The Special Issue on the Western Superior Province Lithoprobe and NATMAP transects presents a wide spectrum of contributions from coordinated, multidisciplinary research projects on the western region of Earth's largest Archean craton. Articles include aspects of the geophysical, stratigraphic, geochemical, geochronological, petrological, and structural evidence bearing on the accretionary history of this classic, well-exposed piece of ancient continental crust, as well as analyses of the prospectivity and seismic character of the gold-rich Red Lake greenstone belt.

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