Grégoire M., Jego S., Maury R. C., Polvé Mireille, Payot B., Tamayo R. A., Yumul G. P. (2008). Metasomatic interactions between slab-derived melts and depleted mantle : insights from xenoliths within Monglo adakite (Luzon arc, Philippines). Lithos, 103 (3-4), p. 415-430. ISSN 0024-4937.
Titre du document
Metasomatic interactions between slab-derived melts and depleted mantle : insights from xenoliths within Monglo adakite (Luzon arc, Philippines)
Grégoire M., Jego S., Maury R. C., Polvé Mireille, Payot B., Tamayo R. A., Yumul G. P.
Source
Lithos, 2008,
103 (3-4), p. 415-430 ISSN 0024-4937
The Monglo adakite contains mafic and ultramafic xenoliths, which probably originated from the mantle section of an Early Cretaceous supra-subduction zone ophiolitic complex located within the Luzon are crust. Spinel-bearing dunites are dominant among this xenolith collection and display evidence for three episodes of subduction-related melt percolation. The first one is evidenced by an undeformed clinopyroxene characterized by convex-upwards REE pattern. This clinopyroxene crystallized from a calc-alkaline basaltic magma, likely formed in the Cretaceous supra-subduction setting of the ophiolite. Then, two metasomatic events, evidenced by orthopyroxene-rich and amphibole-rich secondary parageneses, respectively, affected most of the spine) dunites. The opx-rich paragenesis is related to the circulation within the dunitic upper mantle of hydrous slab-derived melts similar to those affecting the mantle peridotite xenoliths from Papua New Guinea and Kamchatka. Finally the amphibole-rich veins are related to the interaction between the studied dunite xenoliths and the host adakite or an adakitic melt similar to it.
