Geochemical characteristics of granitoid rocks from within the Archean Michipicoten Greenstone Belt, Wawa Subprovince, Superior Province, Canada: implications for source regions and tectonic evolution

Sage, R. P.; Lightfoot, Peter C.; Doherty, W.

doi:10.1016/0301-9268(95)00021-6

Cited by 21 publications

(7 citation statements)

References 41 publications

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“…higher heat production of surface rocks in the Wawa Terrane, as exemplified by the highly radioactive plutons of the Michipicoten greenstone belt (A 0 = 1.43 μW m −3 ) [Sage et al, 1996]. One can also check the heat flow interpretation against evidence from the Kapuskasing structural zone, where a circa 1.9 Ga low-angle thrust has resulted in an oblique cross section through the crust and has exposed parts of the lower crust [Percival and West, 1994].…”

Section: 1002/2014jb011018mentioning

confidence: 99%

“… N number of samples, μ mean, σ standard deviation. References 1 = Wyman et al [], 2 = Fountain et al [], 3 = Tomlinson et al [], 4 = Tomlinson [], 5 = Hollings [], 6 = Tomlinson et al [], 7 = Whalen et al [], 8 = Lesher et al [], 9 = Polat et al [], 10 = Polat and Kerrich [], 11 = Sage et al [], and 12 = [ Shaw et al , ].…”

Section: Heat Flux In the Superior: Large‐scale Analysismentioning

confidence: 99%

“…There are a few isolated high heat flux values (up to 60 mW m −2 ) in the Wawa‐Abitibi and Wabigoon subprovinces, where the presence of enriched granitic intrusions is well‐documented [ Sage et al , ; Polat and Kerrich , ]. Heat production measured on core samples from these sites is sometimes, but not always, higher than the mean for the entire province.…”

Section: Variations Of Crustal Composition Between and Within Terranesmentioning

confidence: 99%

“…These two parts of the same volcanic/plutonic terrane are separated by the Kapuskasing structural zone and have almost the same average heat flux and the same bulk crustal heat production. The difference stems from the higher heat production of surface rocks in the Wawa Terrane, as exemplified by the highly radioactive plutons of the Michipicoten greenstone belt ( A 0 =1.43μWm −3 ) [ Sage et al , ]. One can also check the heat flow interpretation against evidence from the Kapuskasing structural zone, where a circa 1.9 Ga low‐angle thrust has resulted in an oblique cross section through the crust and has exposed parts of the lower crust [ Percival and West , ].…”

Section: Crustal Composition and Structure Of The Craton Building Blocksmentioning

confidence: 99%

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The building and stabilization of an Archean Craton in the Superior Province, Canada, from a heat flow perspective

et al. 2014

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How continental lithosphere responds to tectonic stresses and mantle convective processes is determined in large part by its mechanical strength and temperature distribution, which depend on crustal heat production. In order to establish reliable crustal and thermal models for the Superior Craton, Canadian Shield, new measurements of heat flux and heat production in 28 deep boreholes at 16 sites are combined with a larger set of older data. The Superior Province was assembled by the docking of volcanic/plutonic and metasedimentary terranes and continental fragments to the southern margin of an older core around 2.7 Ga. The average heat flux is much lower in the craton core than in the accreted terranes, 31 versus 43 mW m −2 . The major accreted volcanic/plutonic belts share the same heat production characteristics, testifying to the remarkable uniformity of crust-building mechanisms. The marked difference between the crusts of the core and the accreted belts supports the operation of two different crust-forming processes. The crust of the craton core has an enriched upper layer, in contrast to that of the younger belts which lack marked internal differentiation. At the end of amalgamation, the lithosphere of the craton core was colder and mechanically stronger than the lithosphere beneath newly accreted material. Surrounding the craton core with weaker belts may have ensured its stability against tectonic and mantle convection perturbations. This large strength contrast accounts for the lack of lithospheric imbrication at the edge of the craton core as well as for the different characteristics of seismic anisotropy in the lithospheres of the craton core and the younger terranes.

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Section: 1002/2014jb011018mentioning

confidence: 99%

Section: Heat Flux In the Superior: Large‐scale Analysismentioning

confidence: 99%

Section: Variations Of Crustal Composition Between and Within Terranesmentioning

confidence: 99%

Section: Crustal Composition and Structure Of The Craton Building Blocksmentioning

confidence: 99%

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The building and stabilization of an Archean Craton in the Superior Province, Canada, from a heat flow perspective

et al. 2014

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“…Cenozoic Barnes et al, 2001 Debon et al, 1986Inger and Harris, 1993Thorpe et al, 1990 Paleozoic Azevdo and Nolan, 1998Croudace, 1982 Debon et al, 1986Islam and Gururajan, 1997Jenner et al, 1991Muir et al, 1996Pe-Piper et al, 1991Pressley and Brown, 1999Tate and Clarke, 1997Wiebe and Ulrich, 1997Sun et al, 1993 Proterozoic Annells, 1974Annells, 1973Bourne, 1991Cullers et al, 1993Frost et al, 1999 Goellnicht el al., 1991Jelinek and Dudek, 1993Pollard et al, 1991 Archean Ayres et al, 1991Barley et al, 1984Beakhouse and McNutt, 1991Cassidy et al, 1991Davis et al, 1994 De Ronde et al, 1991 Fend and Kerrich, 1992Gosselin et al, 1990Gower et al, 1983Noble, 1989Paradis et al, 1988Sage et al, 1996bShirey and Hanson, 1986Sun et al, 1993Thurston and Fryer, 1983Witt and Swager, 1989 Volcanic Rocks Cenozoic Baitis and Lindstrom, 1980 Bindeman andValley, 2001 Archean Barley et al, 1984 Fowler and Jensen, 1989Hollings et al, 2000 Jenson and Langford, 1983Muirhead and Hutchinson, 1999Noble, 1989Prior, 1996Thurston and Fryer, 1983Thurston and Fryer, 1983…”

Section: Acknowledgementsmentioning

confidence: 99%

Alkali-Alumina and MgO-Alumina Molar Ratios of Altered and Unaltered Rhyolites

Davies

Whitehead

2006

Exploration and Mining Geology

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Alkali-alumina and MgO-alumina plots are an effective instrument for displaying chemical and mineralogical compositions of altered and unaltered rhyolites and rhyodacites. They reveal that most supposedly unaltered rhyolites, apart from those of Cenozoic age, have undergone losses in Na 2 O and gains in K 2 O. The extreme loss of Na 2 O from highly altered rhyolites immediately adjacent to VMS deposits is strikingly illustrated by alkali-alumina plots. MgO/Al 2 O 3 vs. K 2 O/Al 2 O 3 diagrams display a strong negative correlation between MgO and K 2 O that results from the conversion of sericite to chlorite. A similar negative correlation between MgO and whole-rock δ 18 O is apparent on plots of these two parameters. Alkali-alumina plots underscore problems in selecting appropriate precursor compositions required for mass-balance calculations. Molar ratio plots are a viable alternative to such calculations.

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