For example: Eclogites could represent a range of protoliths such as picritic basalts crystallized in magma chambers within the mantle, subducted ocean floor or delaminated lower crustal material. Any papers/articles?
Thank you Mr. Liu.
If I have at all understood from various sources is that garnets from most mantle eclogites have δ18O values in a narrow range, +5.36 ± 0.18 close to mantle values. On the other hand, eclogites formed from subducted ocean floor has large range δ18O values. Now, I am not getting how is the oxygen fractionation taking place inside/between the existing mineral pairs. What are the driving factors responsible for that?
A good review of d18O of minerals and rocks in mafic eclogites is in the work of Miller, Buick and Cartwright et al.
Miller, J. A., Cartwright, I., Buick, I. & Barnicoat, A. (2001). An O-isotope profile through the HP-LT Corsican ophiolite, France and its implications for fluid flow during subduction. Chemical Geology 178, 43-69.
Miller, J. A. & Cartwright, I. (2000). Distinguishing between seafloor alteration and fluid flow during subduction using stable isotope geochemistry: examples from Tethyan ophiolites in the Western Alps. Journal of Metamorphic Geology 18, 467-482.
For d18O in garnet from eclogites nice works are below, not all of them are oceanic crust but you will see a variety of d18O due to oceanic alteration, interaction with serpentinite and sedimentary fluids during subduction.
Errico, J. C., Barnes, J. D., Strickland, A. & Valley, J. W. (2013). Oxygen isotope zoning in garnets from Franciscan eclogite blocks: Evidence for rock-buffered fluid interaction in the mantle wedge. Contributions to Mineralogy and Petrology 166, 1161-1176.
Page, F. Z., Essene, E. J., Mukasa, S. B. & Valley, J. W. (2014). A garnet-zircon oxygen isotope record of subduction and exhumation fluids from the Franciscan complex, California. Journal of Petrology 55, 103-131.
Russell, A. K., Kitajima, K., Strickland, A., Medaris Jr, L. G., Schulze, D. J. & Valley, J. W. (2013). Eclogite-facies fluid infiltration: Constraints from d18O zoning in garnet. Contributions to Mineralogy and Petrology 165, 103-116.
Rubatto, D. & Angiboust, S. (2015). Oxygen isotope record of oceanic and high-pressure metasomatism: a P-T-time-fluid path for the Monviso eclogites (Italy) Contributions to Mineralogy and Petrology in press.
Thank you Daniela Ma'am. I will come to you after reading the articles if I did not understand.
Thank you Menzies Sir.
In mantle, if there is no metasomatism then whatever δ18O change is observed in eclogite is close to mantle values i.e. +5.5‰. Then how to explain the processes and its geodynamic significance. Can we infer about the processes from mantle eclogites?
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