Petrological and geochemical characteristics of the Samar Ophiolite ultramafic section: implications on the origins of the ophiolites in Samar and Leyte islands, Philippines

Cretaceous ophiolites and ophiolitic fragments occur in the Samar and Leyte islands in eastern central Philippines. The Samar Ophiolite is a complete crust-mantle sequence exposed in southern Samar, whereas the Tacloban and Malitbog ophiolite complexes are, respectively, located in the northeastern...

Full description

Saved in:
Bibliographic Details
Published in:International geology review 2018-03, Vol.60 (4), p.401-417
Main Authors: Guotana, J. M. R., Payot, B. D., Dimalanta, C. B., Ramos, N. T., Faustino-Eslava, D. V., Queaño, K. L., Yumul, G. P.
Format: Article
Language:English
Subjects:
Abyssal zone
arc-backarc pair
Cretaceous
Earth
forearc
Fragments
Genetic relationship
Geochemistry
Islands
Magma
Mantle
Oceanic crust
Ophiolite
Ophiolites
Philippines
Rare earth elements
Samar
Subduction
Subduction zones
supra-subduction zone
Zirconium
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Cretaceous ophiolites and ophiolitic fragments occur in the Samar and Leyte islands in eastern central Philippines. The Samar Ophiolite is a complete crust-mantle sequence exposed in southern Samar, whereas the Tacloban and Malitbog ophiolite complexes are, respectively, located in the northeastern and southwestern portions of the nearby Leyte island. Despite the close proximity of these islands, the genetic relationship of these ophiolites and ophiolitic complexes, if any, remains to be elucidated. We present here new petrographic and geochemical data on the harzburgites and dunites of the ultramafic section of the Samar Ophiolite. These mantle peridotites are highly depleted residues which have low modal pyroxene content, high spinel Cr# (=0.62-0.79), and slightly enriched light rare earth element abundance with depletion in Zr and Ti. Such characteristics are typical of supra-subduction zone peridotites and strongly contrast with the abyssal signatures of the Tacloban and Malitbog ophiolite complexes. The absence of a structure between these adjacent ophiolite fragments initially hints that they form a single oceanic crust. However, with our new results, we suggest other possible mechanisms that could explain the relationship of these ophiolites.
ISSN:0020-6814
1938-2839
DOI:10.1080/00206814.2017.1336944