High-18O granitic plutons from the Frontenac Axis, Grenville province of ontario, Canada

Shieh, Yuch‐Ning

doi:10.1016/0016-7037(85)90195-4

Cited by 23 publications

(14 citation statements)

References 26 publications

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“…These oxygen-isotope ratios are typical of the high end of variation seen in common granitic rocks (e.g., Taylor and Sheppard, 1986). Granitic rocks in the Frontenac terrane have δ 18 O(WR) = 9 to 16‰ (Shieh, 1985;Marcantonio et al, 1990; this study), a range much higher than reported igneous values from granitic rocks (see Taylor and Sheppard, 1986). Gabbros from the Central Metasedimentary Belt of Québec range from ∼7 to 11‰ (Appendix 2; Fig.…”

Section: Oxygen Isotope Resultsmentioning

confidence: 80%

“…The observed correlation of SiO 2 and δ 18 O(WR) could result from contamination by supracrustal material with high δ 18 O, or from assimilation fractional crystallization (AFC) processes, which would increase the δ 18 O of igneous rocks as they differentiate (e.g., Taylor and Sheppard, 1986). In addition to the consistency with AFC models, good petrologic and isotopic evidence for preservation of igneous δ 18 O values and against resetting by exchange with metamorphic fluids is documented in the Adirondack Highlands and in the Frontenac and Morin terranes (e.g., Valley and O'Neil, 1984;Shieh, 1985;Morrison and Valley, 1988;Valley et al, 1990Valley et al, , 1994Peck and Valley, 2000).…”

Section: Oxygen-isotope Ratios Of Whole Rocksmentioning

confidence: 95%

“…Common field observation of calc-silicate, skarn, and quartzite xenoliths and the absence of biotite-bearing and quartzofeldspathic xenoliths (which are abundant country rocks) point toward efficient assimilation of country rocks that have lower melting temperatures. High and variable δ 18 O(WR) for the Chevreuil suite cannot be explained by some country rocks with unusually high δ 18 O values; none of the country rocks analyzed in the quartzite domain has an unusual δ 18 O value compared to the values of supracrustal rocks elsewhere in the Grenville Province (e.g., Taylor, 1969;Shieh and Schwarcz, 1978;Shieh, 1985;Wu and Kerrich, 1986;Marcantonio et al, 1990;Peck, 2000; Appendixes 1, 2, and 5). This conclusion is supported by oxygen-isotope ratios of vertically layered mafic intrusions associated with the Chevreuil suite in the quartzite domain (Fig.…”

Section: Oxygen-isotope Ratios Of Whole Rocksmentioning

confidence: 95%

“…Because the emplacement style and volume of AMCG suite and contemporaneous plutonic rocks vary across the area, correlation of these rocks between lithotectonic terranes is possible only through precise U-Pb zircon geochronology of rocks that include syenite, monzonite, granite, charnockite, mangerite, and jotunite, and have been the foci of numerous igneous petrology and geochemistry studies (e.g., Buddington, 1939;Heath and Fairbairn, 1969;Martignole and Schrijver, 1970;Barton and Doig, 1977;Ashwal and Wooden, 1983;Shieh, 1985;Wu and Kerrich, 1986;Morrison and Valley, 1988;Lumbers et al, 1990;Marcantonio et al, 1990;McLelland and Whitney, 1990;Valley et al, 1990Valley et al, , 1994Daly and McLelland, 1991;Doig, 1991;Emslie and Hegner, 1993;McLelland et al, 1993;Owens et al, 1993;Eiler and Valley, 1994;Rockow, 1995;Davidson and van Breemen, 2000;Peck and Valley, 2000). These granitoids have A-type, subalkalic to alkalic chemistries (Irvine and Baragar, 1971), alkali-calcic to calc-alkaline Peacock (1931) indexes, show little iron enrichment in AFM diagrams, are metaluminous (Shand, 1951), have flat heavy rare earth element patterns, and plot as within-plate granites on tectonic discrimination diagrams (e.g., Pearce et al, 1984).…”

Section: Amcg Suite and Contemporaneous Plutonism In The Monocyclic Beltmentioning

confidence: 99%

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Oxygen-isotope constraints on terrane boundaries and origin of 1.18–1.13 Ga granitoids in the southern Grenville Province

Peck

Valley²,

Corriveau³

et al. 2004

Memoir 197: Proterozoic Tectonic Evolution of the Grenville Orogen in North America

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Granitic rocks related to 1.18 to 1.13 Ga anorthosite-mangerite-charnockitegranite plutonism stitch three terranes in the southwestern Grenville Province (Adirondack Highlands-Morin terrane, Frontenac terrane, Elzevir terrane). Because of the refractory nature of zircon (Zrn), analysis of oxygen-isotope ratios of dated igneous zircon from these rocks allows calculation of δ δ 18 O values of original magmas even if the rocks were subjected to late magmatic assimilation, postmagmatic alteration, or metamorphism. Documented variability in δ δ 18 O(Zrn) for these granitic rocks corresponds to their geographic location. Seven plutons from the central Frontenac terrane (Ontario) have a high average δ δ 18 O(Zrn) = 11.8 ± ± 1.0‰, which corresponds to δ δ 18 O magma values of 12.4-14.3‰. In contrast, twenty-seven other plutons and dikes of this suite (New York, Ontario, and Québec) average δ δ 18 O(Zrn) = 8.2 ± ± 0.6‰, with a typical igneous range of 8.6 to 10.3‰ for δ δ 18 O magma values. High δ δ 18 O values in the Frontenac terrane are some of the highest magmatic oxygen-isotope ratios recognized worldwide, but these plutons are not unusual with respect to whole-rock chemistry or radiogenic isotope compositions. Such high δ δ 18 O values can result from mixing between paragneiss (δ δ 18 O ≈ ≈ 15‰) and hydrothermally altered basalts and/or oceanic sediments (δ δ 18 O ≈ ≈ 12‰) in the source region. We propose that high-δ δ 18 O, hydrothermally altered basalts and sediments were subducted or underthrust to the base of the Frontenac terrane during closure of an ocean basin between the Frontenac terrane and the Adirondack Highlands at or prior to 1.2 Ga.

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Section: Oxygen Isotope Resultsmentioning

confidence: 80%

Section: Oxygen-isotope Ratios Of Whole Rocksmentioning

confidence: 95%

Section: Oxygen-isotope Ratios Of Whole Rocksmentioning

confidence: 95%

Section: Amcg Suite and Contemporaneous Plutonism In The Monocyclic Beltmentioning

confidence: 99%

See 2 more Smart Citations

Oxygen-isotope constraints on terrane boundaries and origin of 1.18–1.13 Ga granitoids in the southern Grenville Province

Peck

Valley²,

Corriveau³

et al. 2004

Memoir 197: Proterozoic Tectonic Evolution of the Grenville Orogen in North America

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“…Hoernes & Hoffer (1985) found quartz-feldspar frac-K 2 O>Na 2 O, A.S.I.>1.1), it seems likely that the leucosomes were derived from metasedimentary tionations between 1.10 and 1.34 in leucosomes and 1.08 and 1.13 in granites from the Central Damara sources (Chappel & White, 1977;Miller, 1985). Leucosome LEU 1 probably represents the initial orogen, values typical for unaltered granites worldwide (Shieh, 1985). Based on these fractionations between intrusive melt.…”

Section: Partial Meltingmentioning

confidence: 96%

Petrology of an intrusion‐related high‐grade migmatite: implications for partial melting of metasedimentary rocks and leucosome‐forming processes

Jung

Mezger

Masberg³

et al. 1998

Journal Metamorphic Geology

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Intrusion-related migmatites comprise a substantial part of the high-grade part of the southern Damara orogen, Namibia which is dominated by Al-rich metasedimentary rocks and various granites. Migmatites consist of melanosomes with biotite+sillimanite+garnet+cordierite+hercynite and leucosomes are garnet-and cordierite-bearing. Metamorphic grade throughout the area is in the upper amphibolite to lower granulite facies (5-6 kbar at 730-750°C). Field evidence, petrographic observations, chemical data and mass balance calculations suggest that intrusion of granitic magmas and concomitant partial melting of metasedimentary units were the main processes for the generation of the migmatites. The intruding melts were significantly modified by magma mixing with in situ partial melts, accumulation of mainly feldspar and contamination with garnet from the wall rocks. However, it is suggested that these melts originally represented disequilibrium melts from a metasedimentary protolith. The occurrence of LILE-, HFSE-and LREE-enriched and -depleted residues within the leucosomes implies that both quartzofeldspathic and pelitic rocks were subjected to partial melting. Isotope ratios of the leucosomes are rather constant (143Nd/144Nd (500 Ma): 0.511718-0.511754, e Nd (500 Ma): −3.54 to −5.11) and Sr (87Sr/86Sr (500 Ma): 0.714119-0.714686), the metasedimentary units have rather constant Nd isotope ratios (143Nd/144Nd (500 Ma): 0.511622-0.511789, e Nd (500 Ma): −3.70 to −6.93) but variable Sr isotope ratios Sr (87Sr/86Sr (500 Ma): 0.713527-0.722268). The most restitic melanosome MEL 4 has a Sr isotopic composition of 87Sr/86Sr (500 Ma): 0.729380. Oxygen isotopes do not mirror the proposed contamination process, due to the equally high d18O contents of metasediments and crustal melts. However, the most LILE-depleted residue MEL 4 shows the lowest d18O value (<10‰). Mass balance calculations suggest high degrees of partial melting (20-40%). It is concluded that partial melting was promoted by heat transfer and release of a fluid phase from the intruding granites. High degrees of partial melting can be reached as long as the available H 2 O, derived from the crystallization of the intruding granites, is efficiently recycled within the rock volume. Due to the limited amounts of in situ melting, it seems likely that such regional migmatite terranes are not the sources for large intrusive granite bodies. The high geothermal gradient inferred from the metamorphic conditions was probably caused by exhumation of deep crustal rocks and contemporaneous intrusion of huge masses of granitoid magmas. The Davetsaub area represents an example of migmatites formed at moderate pressures and high temperatures, and illustrates some of the reactions that may modify leucosome compositions. The area provides constraints on melting processes operating in high-grade metasedimentary rocks.Key words: anatexis; migmatite; Namibia; Nd and Sr isotopes; oxygen isotopes; trace elements.shown that, although the large-scale extraction of INTRODU CTION g...

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Fluid—rock interaction in the north-west Adirondack Mountains, New York State

Cartwright¹,

Valley²

1990

High-Temperature Metamorphism and Crustal Anatexis

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High-18O granitic plutons from the Frontenac Axis, Grenville province of ontario, Canada

Cited by 23 publications

References 26 publications

Oxygen-isotope constraints on terrane boundaries and origin of 1.18–1.13 Ga granitoids in the southern Grenville Province

Oxygen-isotope constraints on terrane boundaries and origin of 1.18–1.13 Ga granitoids in the southern Grenville Province

Petrology of an intrusion‐related high‐grade migmatite: implications for partial melting of metasedimentary rocks and leucosome‐forming processes

Fluid—rock interaction in the north-west Adirondack Mountains, New York State

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