fic magmas: evidence from a neral phases are olivine, clinopyroxene, Fe–Ti oxides, amphibole, plagioclase and alkali feldspar. Quartz occurs in some samples as a late magmatic phase. Liquidus temperatures of olivine-bearinga relative enrichment of LIL elements with Ba peaks andNb troughs. Clinopyrox...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.548.6756 2023-05-15T16:29:57+02:00 Ralf Halamaa Michael Marksa Wolfgang Siebela Thomas Wenzela Gregor Markla Themid-proterozoic Isortoq Di The Pennsylvania State University CiteSeerX Archives 2003 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.548.6756 http://homepages.uni-tuebingen.de/wolfgang.siebel/pdffiles/halama_2004.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.548.6756 http://homepages.uni-tuebingen.de/wolfgang.siebel/pdffiles/halama_2004.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://homepages.uni-tuebingen.de/wolfgang.siebel/pdffiles/halama_2004.pdf text 2003 ftciteseerx 2016-01-08T11:24:38Z fic magmas: evidence from a neral phases are olivine, clinopyroxene, Fe–Ti oxides, amphibole, plagioclase and alkali feldspar. Quartz occurs in some samples as a late magmatic phase. Liquidus temperatures of olivine-bearinga relative enrichment of LIL elements with Ba peaks andNb troughs. Clinopyroxenes show a general enrichment in REE relative to chondritic values with variable slightly positive to prominent negative Eu anomalies. Two of the dikes were dated with Sm–Nd three-point isochrons at 1190F 44 and 1187F 87 Ma, respectively. Initial 87Sr/86Sr ratios of mafic mineral separates range from 0.70289 to 0.70432 and initial eNd values vary from + 0.3 to 10.7. Whole-rock initial 187Os/188Os ratios are highly variable including very radiogenic values of up to 7.967. d18Ov-smow values of separated clinopyroxene and amphibole range from + 5.2x to + 6.2xand fall within the range of typical mantle-derived rocks, although mixing with a lower crustal component is permitted by the data. Using energy-constrained assimilation-fractional crystallization (EC-AFC) modeling equations, the Sr–Nd isotope data of the more radiogenic samples can successfully be modeled by addition of up to 10 % lower crustal granulite-facies Archean gneisses as contaminants. The Os isotopic data also suggest the involvement of old radiogenic crust. In accordance with seismic data, we conclude that a wedge of Archean crust extends fromWest Greenland further to the south below the present erosion level. D 2004 Elsevier B.V. All rights reserved.The rocks haveMgO contents < 6wt.%withMg # between 5samples range between 1120 and 1145 jC and solidus temperatures are 850–930 jC. Calculated silica activities are highly variable between 0.53 and unity. Oxygen fugacities vary from 3 to + 1 log units relative to the fayalite–magnetite–quartz buffer. 3 and 17. Primitivemantle-normalized trace element patterns showfrom gabbroic to syenitic in composition. Major magmatic mipetrological, geochemical and Sr–Nd–Os–O isotopic study of the Text Greenland Unknown Greenland Neral ENVELOPE(93.533,93.533,68.317,68.317) |
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Open Polar |
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ftciteseerx |
language |
English |
description |
fic magmas: evidence from a neral phases are olivine, clinopyroxene, Fe–Ti oxides, amphibole, plagioclase and alkali feldspar. Quartz occurs in some samples as a late magmatic phase. Liquidus temperatures of olivine-bearinga relative enrichment of LIL elements with Ba peaks andNb troughs. Clinopyroxenes show a general enrichment in REE relative to chondritic values with variable slightly positive to prominent negative Eu anomalies. Two of the dikes were dated with Sm–Nd three-point isochrons at 1190F 44 and 1187F 87 Ma, respectively. Initial 87Sr/86Sr ratios of mafic mineral separates range from 0.70289 to 0.70432 and initial eNd values vary from + 0.3 to 10.7. Whole-rock initial 187Os/188Os ratios are highly variable including very radiogenic values of up to 7.967. d18Ov-smow values of separated clinopyroxene and amphibole range from + 5.2x to + 6.2xand fall within the range of typical mantle-derived rocks, although mixing with a lower crustal component is permitted by the data. Using energy-constrained assimilation-fractional crystallization (EC-AFC) modeling equations, the Sr–Nd isotope data of the more radiogenic samples can successfully be modeled by addition of up to 10 % lower crustal granulite-facies Archean gneisses as contaminants. The Os isotopic data also suggest the involvement of old radiogenic crust. In accordance with seismic data, we conclude that a wedge of Archean crust extends fromWest Greenland further to the south below the present erosion level. D 2004 Elsevier B.V. All rights reserved.The rocks haveMgO contents < 6wt.%withMg # between 5samples range between 1120 and 1145 jC and solidus temperatures are 850–930 jC. Calculated silica activities are highly variable between 0.53 and unity. Oxygen fugacities vary from 3 to + 1 log units relative to the fayalite–magnetite–quartz buffer. 3 and 17. Primitivemantle-normalized trace element patterns showfrom gabbroic to syenitic in composition. Major magmatic mipetrological, geochemical and Sr–Nd–Os–O isotopic study of the |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Ralf Halamaa Michael Marksa Wolfgang Siebela Thomas Wenzela Gregor Markla Themid-proterozoic Isortoq Di |
spellingShingle |
Ralf Halamaa Michael Marksa Wolfgang Siebela Thomas Wenzela Gregor Markla Themid-proterozoic Isortoq Di |
author_facet |
Ralf Halamaa Michael Marksa Wolfgang Siebela Thomas Wenzela Gregor Markla Themid-proterozoic Isortoq Di |
author_sort |
Ralf Halamaa |
publishDate |
2003 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.548.6756 http://homepages.uni-tuebingen.de/wolfgang.siebel/pdffiles/halama_2004.pdf |
long_lat |
ENVELOPE(93.533,93.533,68.317,68.317) |
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Greenland Neral |
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Greenland Neral |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
http://homepages.uni-tuebingen.de/wolfgang.siebel/pdffiles/halama_2004.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.548.6756 http://homepages.uni-tuebingen.de/wolfgang.siebel/pdffiles/halama_2004.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766019667287080960 |