Item type |
紀要論文(ELS) / Departmental Bulletin Paper(1) |
公開日 |
2003-10-01 |
タイトル |
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タイトル |
Geochemistry and preliminary Sr-Nd isotopic data on the Neoproterozoic granitoids from the Bantoum area, west Cameroon: evidence for a derivation from a Paleoproterozoic to Archaean crust |
言語 |
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言語 |
eng |
キーワード |
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主題Scheme |
Other |
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主題 |
granite |
キーワード |
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主題Scheme |
Other |
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主題 |
geochemistry |
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主題Scheme |
Other |
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主題 |
Sr-Nd isotope |
キーワード |
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主題Scheme |
Other |
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主題 |
crustal recycling |
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主題Scheme |
Other |
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主題 |
west-Cameroon |
資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
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資源タイプ |
departmental bulletin paper |
ID登録 |
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ID登録 |
10.15094/00003129 |
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ID登録タイプ |
JaLC |
ページ属性 |
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内容記述タイプ |
Other |
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内容記述 |
P(論文) |
著者名(英) |
Nzolang, Charles
Kagami, Hiroo
Nzenti, Jean Paul
Holtz, Francois
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著者所属(英) |
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en |
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Graduate School of Science and Technology, Niigata University |
著者所属(英) |
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en |
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Graduate School of Science and Technology, Niigata University |
著者所属(英) |
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en |
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Departement des Sciences de la Terre, Universite de Yaounde |
著者所属(英) |
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en |
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Institut fur Mineralogie,Universitat Hannover |
抄録(英) |
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内容記述タイプ |
Other |
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内容記述 |
The Bantoum area in west Cameroon is composed of migmatitic gneisses associated with parallel strips of amphibolites,quartz-monzonites,biotite-granites, two-mica leucogranites and granitic dikes.Quartz-monzonites are metaluminous (A/CNK=0.8-0.9)I-type,biotite-granites are peraluminous (A/CNK=1.0-1.10)I-type, leucogranites are peraluminous (A/CNK=1.14)S-type granitoids.All are hyper-potassic rocks defining a calc-alkaline trend.Quartz-monzonites gave an Rb-Sr isochron age of 720+-61 Ma assumed to be a mixing age.The thermometry estimated from major elements and zircon saturation indicate that the biotite-granites crystallized from high temperature melts (812-866゜C) whereas leucogranites crystallized from low temperature melts (719-745゜C). The trace element distribution diagrams are characterized by an enrichment in LILE and LREE (5<La_N/Sm_N<17),with negative Nb,Ta,Sr and Ti anomalies. Model initial ^87Sr/^86 Sr ratios (620 Ma)are 0.707614-0.708363 for quartz-monzonites,0.711242-0.713784 for biotite-granites,and 0.715835 for leucogranites.They have highly negative ε_Nd (620 Ma)(-19~-11) and T_DM model ages ranging from 1.9 to 2.9 Ga. These geochemical and isotopic features imply that the granites are generated at different temperatures and from different crustal materials;they are the witnesses of the recycling of a Paleoproterozoic to Archean crust with minor inputs of juvenile magmas during the Pan-African orogeny. Chemical similarities between gneisses and some biotite-granites suggest that the partial melting of these gneisses may have contributed to the formation of granites. |
雑誌書誌ID |
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収録物識別子タイプ |
NCID |
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収録物識別子 |
AA1130866X |
書誌情報 |
Polar geoscience
巻 16,
p. 196-226,
発行日 2003-10
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出版者 |
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出版者 |
National Institute of Polar Research |