Present address: Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa City, Ishikawa 920-1192, Japan (email: email@example.com).
The oceanic substratum of Northern Luzon: Evidence from xenoliths within Monglo adakite (the Philippines)
Article first published online: 16 APR 2007
Volume 16, Issue 2, pages 276–290, June 2007
How to Cite
Payot, B. D., Jego, S., Maury, R. C., Polve, M., Gregoire, M., Ceuleneer, G., Tamayo, R. A., Yumul, G. P., Bellon, H. and Cotten, J. (2007), The oceanic substratum of Northern Luzon: Evidence from xenoliths within Monglo adakite (the Philippines). Island Arc, 16: 276–290. doi: 10.1111/j.1440-1738.2007.00574.x
- Issue published online: 16 APR 2007
- Article first published online: 16 APR 2007
- Received 17 February 2006; accepted for publication 21 February 2007.
- Luzon crust;
- the Philippines;
Abstract A 8.65 Ma adakitic intrusive sheet exposed near Monglo village in the Baguio District of Northern Luzon contains a suite of ultramafic and mafic xenoliths including in order of abundance: spinel dunites showing typical mantle-related textures, mineral and bulk rock compositions, and serpentinites derived from them; amphibole-rich gabbros displaying incompatible element patterns similar to those of flat or moderately enriched back-arc basin basalt magmas; and amphibolites derived from metabasalts and/or metagabbros of identical affinity. A single quartz diorite xenolith carrying a similar subduction-related geochemical signature has also been sampled. One amphibolite xenolith provided a whole-rock K–Ar age of 115.6 Ma (Barremian). We attribute the origin of this suite to the sampling by ascending adakitic magmas of a Lower Cretaceous ophiolitic complex located at a depth within the 30–35 km thick Luzon crust. It could represent an equivalent of the Isabela-Aurora and Pugo-Lepanto ophiolitic massifs exposed in Northern Luzon.