Petrological Characteristics and Genesis of the Central Indian Ocean Basin Basalts
DRS at CSIR-National Institute of Oceanography
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Title |
Petrological Characteristics and Genesis of the Central Indian Ocean Basin Basalts
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Creator |
Das, P.
Iyer, S.D. Hazra, S. |
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Subject |
basalts
petrology |
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Description |
The Central Indian Ocean Basin (CIOB) basalts are plagioclase-rich, while olivine and pyroxene are very few. The analyses of 41 samples reveal high FeO sup(T) (approx. 10-18 wt percent) and TiO sub(2) (approx. 1.4-2.7 wt percent) indicating a ferrobasaltic composition. The basalts have high incompatible elements (Zr 63-228 ppm; Nb approx. 1-5 ppm; Ba approx. 15-78 ppm; La approx. 3-16 ppm), a similar U/Pb (0.02-0.4) ratio as the normal mid-oceanic basalt (0.16 plus or minus 0.07) but the Ba/Nb (12.5-53) ratio is much larger than that of the normal mid-oceanic ridge basalt (approx. 5.7) and Primitive Mantle (9.56). Interestingly almost all of the basalts have a significant negative Eu anomaly (Eu/Eu*=0.78-1.00) that may have been a result of the removal of feldspar and pyroxene during crystal fractionation. These compositional variations suggest that the basalts were derived through fractional crystallization together with low partial melting of a shallow seated magma.
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Date |
2012-12-05T06:11:29Z
2012-12-05T06:11:29Z 2012 |
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Type |
Journal Article
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Identifier |
Acta Geologica Sinica, vol.86(5); 2012; 1154-1170
no http://drs.nio.org/drs/handle/2264/4200 |
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Language |
en
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Relation |
Acta_Geol_Sin_86_1154.jpg
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Rights |
An edited version of this paper was published by Springer/Geological Society of China. This paper is for R & D purpose and Copyright [2012] Springer.
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Publisher |
Geological Society of China
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