Formation of podiform chromitites by melt/rock interaction in the upper mantle

1994 ◽  
Vol 29 (1) ◽  
pp. 98-101 ◽  
Author(s):  
M. F. Zhou ◽  
P. T. Robinson ◽  
W. J. Bai
Keyword(s):  
Upper Mantle ◽  
Rock Interaction ◽  
Podiform Chromitites

Evaluating the roles of melt-rock interaction and partial degassing on the CO2/Ba ratios of MORB: Implications for the CO2 budget in the Earth’s depleted upper mantle

2019 ◽  
Vol 260 ◽  
pp. 29-48 ◽  
Author(s):  
Kei Shimizu ◽  
Alberto E. Saal ◽  
Erik H. Hauri ◽  
Michael R. Perfit ◽  
Roger Hékinian
Keyword(s):  
Upper Mantle ◽  
Rock Interaction

Multiple events in the Neo-Tethyan oceanic upper mantle: Evidence from Ru–Os–Ir alloys in the Luobusa and Dongqiao ophiolitic podiform chromitites, Tibet

2007 ◽  
Vol 261 (1-2) ◽  
pp. 33-48 ◽  
Author(s):  
Rendeng Shi ◽  
Olivier Alard ◽  
Xiachen Zhi ◽  
Suzanne Y. O'Reilly ◽  
Norman J. Pearson ◽  
...  
Keyword(s):  
Upper Mantle ◽  
Multiple Events ◽  
Podiform Chromitites

Podiform chromitites in lherzolitic mantle rocks (Andaman ophiolite, India): the role of magma/rock interaction and parental melt composition

2014 ◽  
Vol 185 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Biswajit Ghosh ◽  
Koyel Bhatta
Keyword(s):  
Subduction Zone ◽  
East Coast ◽  
Volcanic Rocks ◽  
Atomic Ratio ◽  
Rock Interaction ◽  
South Andaman ◽  
Podiform Chromitites ◽  
Melt Composition ◽  
Host Rocks

Abstract In this study, Alpine-type (ophiolite hosted) podiform chromitites from the lherzolite dominant mantle sequence of the Andaman ophiolite, India are described. The mantle host rocks for the chromitite pods show features of melt-mantle interaction. The chromites of the podiform chromitites have high-Cr# (= Cr/[Cr + Al] atomic ratio) ranging between 0.69 and 0.75 and high-Mg# (= Mg/[Mg + Fe2+] atomic ratio) ranging between 0.58 and 0.72. Geochemically, the chromites of these high-Cr chromitites have an arc-spinel trend and suggest a supra-subduction zone setting. Contrarily, the low-Cr chromitites (reported elsewhere) show MORB-spinel trend. Parent melt composition is assessed on the basis of liquidus chromite compositions using various methods. The deduced composition shows that the melt parental to the high-Cr chromitite of the Andaman ophiolite had 12–13 wt.% Al2O3 and 0.2–0.5 wt.% TiO2 whereas the same for the low-Cr chromitites had ~ 16 wt.% Al2O3 and 0.5–0.9 wt.% TiO2. A correlation of the deduced parent melt compositions with the volcanic rocks of the Andaman ophiolite suggests a close affinity with the East Coast volcanics (south-Andaman) for the high-Cr chromitites. Contrarily, a similar correlation for the low-Cr chromitites is not so certain.

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