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Acasta Gneiss

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Journal Article
Journal: Geology
Published: 01 April 2006
Geology (2006) 34 (4): 245-248.
... report the first occurrence of a very old zircon with a U-Pb age of 4.2 Ga in the Acasta Gneiss Complex of northwestern Canada, based on a laser ablation-inductively coupled plasma–mass spectrometry and sensitive high-resolution ion microprobe study. The U-Pb data reveal that the 4.2 Ga zircon occurs...
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Image
The 4.03 Ga <b>Acasta</b> <b>Gneiss</b> from the Slave Craton of northwestern Canada is E...
in > Elements
Published: 01 February 2010
The 4.03 Ga Acasta Gneiss from the Slave Craton of northwestern Canada is Earth's oldest-known rock unit. In this polished section (about 10 cm wide), the gneiss contains strongly deformed granite veins 3.6 billion years old. C ourtesy of W. B leeker
Image
The 4.03 Ga <b>Acasta</b> <b>Gneiss</b> from the Slave Craton, northwestern Canada, the o...
Published: 01 November 2008
F igure 6. The 4.03 Ga Acasta Gneiss from the Slave Craton, northwestern Canada, the oldest known rock unit on Earth, is crosscut by 3.6 Ga granite veins. Photo by W. Bleeker.
Journal Article
Journal: Geology
Published: 01 November 1989
Geology (1989) 17 (11): 971-975.
...S. A. Bowring; I. S. Williams; W. Compston Abstract Ion microprobe U-Pb analyses of zircons have identified the Acasta gneisses, from the westernmost Slave province, Canada, as the oldest known intact terrestrial rocks. Zircons from two samples indicate that the tonalitic to granitic protoliths...
Journal Article
Journal: Geology
Published: 01 July 2007
Geology (2007) 35 (7): 643-646.
... reservoirs like that of modern mid-ocean ridge basalt (MORB) in both modern and ancient detrital zircon populations. Hadean detrital zircons previously reported from the Acasta Gneiss, Canada, and the Narryer Gneiss terrane, Western Australia, plot in the continental granitoid field, supporting hypotheses...
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Series: GSA Special Papers
Published: 01 January 2006
DOI: 10.1130/2006.2405(05)
... indicates that a large proportion of the Paleoarchean zircon from both samples was derived by reworking of significantly older crust, consistent with previously published evidence for scarce pre–4.0 Ga continental crust from Jack Hills, Australia, and the Acasta Gneiss, Canada. When comparing the detrital...
Series: DNAG, Geology of North America
Published: 01 January 1998
DOI: 10.1130/DNAG-GNA-C1.1
EISBN: 9780813754468
... Abstract The Canadian Shield contains a remarkable and extensive record of the Earth's Precambrian geology and tectonic history (Hoffman, 1989). It spans from the oldest known rocks on Earth (Acasta gneiss complex, Slave Province, Fig. 1.1, see colour section; King, 1985; Bowring et al., 1989...
Journal Article
Journal: Geology
Published: 01 April 1992
Geology (1992) 20 (4): 327-330.
.... The concordant analyses of >3.30 Ga indicate that older crustal components with ages up to 3.96 Ga, or detritus from them, were also in the provenance of this quartzite. This older age is equivalent to that of the oldest known rock from the Acasta gneisses of the Slave province and is exceeded only by the >...
Journal Article
Published: 29 July 2016
Canadian Journal of Earth Sciences (2016) 53 (12): 1511-1538.
...W.M. Schwerdtner; Toby Rivers; Jason Tsolas; Dennis H. Waddington; Sydney Page; Jack Yang Abstract The well-mapped western part of the Ottawa River Gneiss Complex (ORGC; new name), a large metamorphic core complex, hosts a system of gently plunging cross-folds of outcrop to regional scale situated...
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Series: Geological Society, London, Special Publications
Published: 01 January 2017
EISBN: 9781786202949
... al. 2007 ). A relatively well-preserved record of a multistage Eoarchaean–Palaeoproterozoic continental crustal history has been reported from the Bug Granulite–Gneiss Complex (BGGC) in the Ukrainian Shield (Fig. 1 a) ( Lesnaya 1988 ; Stepanyuk 1997 , 1998 ; Shcherbak et al. 2005 , 2010...
Journal Article
Journal: GSA Bulletin
Published: 01 January 2006
GSA Bulletin (2006) 118 (1-2): 94-108.
... ancient continental crust include the Acasta gneisses in the Canadian Northwest Territories, which are now known to contain components as old as 4020 Ma (e.g., Bowring et al., 1989 ; Bowring and Williams, 1999 ; Stern and Bleeker, 1998 ), the occurrence of 4.4–4.2 Ga detrital zircons in the Jack Hills...
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Journal Article
Journal: GSA Bulletin
Published: 01 March 2017
GSA Bulletin (2017) 129 (3-4): 259-280.
... and recycling deserves to be studied closely. We present geologic, petrologic, geochemical, and isotopic descriptions of Paleoarchean gneisses in the central Wyoming Province. We identify two groups of gneisses: a bimodal suite of amphibolite and tonalite-trondhjemite-granodiorite (TTG) layered gneisses (3385...
FIGURES
Series: Geological Society, London, Special Publications
Published: 01 January 2008
DOI: 10.1144/SP.308.13
EISBN: 9781862395565
... to the age of the Earth's oldest rocks, the 4000 Ma Acasta Gneiss in Canada ( Bowring et al. 1989 ). In addition, most of the lithologies in the Napier Complex were formed before the 2590–2450 Ma main tectonometamorphic event(s) ( Harley et al. 2001 ; Kelly & Harley 2005 ), and thus are critical...
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Geological sketch map showing the subdivisions of Wopmay orogen discussed i...
Published: 01 May 2010
Figure 1. Geological sketch map showing the subdivisions of Wopmay orogen discussed in this paper. A—Acasta gneiss in Exmouth anticline.
Journal Article
Journal: GSA Bulletin
Published: 01 January 2006
GSA Bulletin (2006) 118 (1-2): 82-93.
...M.D. Schmitz; S.A. Bowring; D.L. Southwick; T.J. Boerboom; K.R. Wirth Abstract High-precision U-Pb ages have been obtained for high-grade gneisses, late-kinematic to postkinematic granitic plutons, and a crosscutting mafic dike of the Archean Minnesota River Valley tectonic subprovince...
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Series: Geological Society, London, Special Publications
Published: 01 January 2002
DOI: 10.1144/GSL.SP.2002.199.01.09
EISBN: 9781862394476
... and shallow-dipping Proterozoic gabbro sill, which is exposed at surface, whereas the lower reflection probably represents the basalt-dominated volcanic stratigraphy between more or less transparent metaturbidites above and mostly felsic basement gneisses below (Fig. 3 ). Hence, despite the compelling...
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Journal Article
Published: 01 March 2009
Journal of the Geological Society (2009) 166 (2): 193-196.
... be noted that old TTG complexes, such as the c . 4 Ga Acasta Gneiss Complex, Slave Craton and the 3.8 Ga Itsaq Gneiss Complex, Greenland, have late-stage potassium-rich differentiates, but unlike the granite reported here, these granitic veins are not sufficiently voluminous in any one place to form...
FIGURES
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(A) Superior Province, showing location of inset (B) of Minto Block. Number...
Published: 01 January 2009
gneisses; (5) Beartooth Mountains, Wyoming Craton; (6) Acasta Gneiss, Slave Province, Northwest Territories. (B) Geological subdivisions of the Minto Block (after Percival et al., 1994 ) in the Northeast Superior Province and location of the Nuvvuagittuq supracrustal sequence and Figure 2 (square
Journal Article
Published: 21 October 2015
Geological Magazine (2016) 153 (1): 179-192.
.... , Johnson S. P. & Dunkley D. J. 2007 . Geology and zircon geochronology of the Acasta Gneiss Complex, northwestern Canada: new constraints on its tectonothermal history . Precambrian Research...
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Crystallization age (U-Pb) and δ 18 O for Archean magmatic zircons. A major...
Published: 02 January 2003
water near the surface of the Earth. The timeline, lower right, shows: 1. accretion of Earth; 2. formation of Moon and Earth’s core; 3. evidence for liquid water; 4. Acasta gneiss; 5. Isua metasediments (from Valley et al. 2002 ).