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7472964 
Journal Article 
Geology of the ophiolite of central Palawan Island, Philippines 
Raschka, H; Nacario, E; Rammlmair, D; Samonte, C; Steiner, L 
1985 
1 
Ofioliti
ISSN: 0391-2612 
10 
2-3 
375-389 
English 
The central part of Palawan Island is composed predominantly of ophiolitic rocks stretching for approx 100 km in a SW-NE direction. This complex fills the requirements of a complete ophiolite. It is built up of a basal tectonized peridotite that consists mainly of foliated harzburgite and dunite; this grades upward via foliated troctolite to the gabbro unit that is generally foliated but exhibits massive, isotropic fabrics in its highest level. The uppermost unit of the ophiolite sequence is formed by pillow basalts with associated cherts. Microgabbro dykes cut the whole sequence, whereas pyroxenite and dunite dykes are restricted to the peridotite unit, and plagiogranites to the upper gabbro unit. A sheeted dyke complex is missing. Chromite stringers and bodies are associated with dunite. The ophiolite is overlain by flyschoid sediments, either deformed or undeformed, the palaeontological age of which ranges from late Cretaceous to Oligocene. They are covered by younger shallow water sediments. Intensely foliated rocks of mainly basaltic origin are associated with the peridotite contacts towards flyschoid sediments and pillow basalts with cherts. They are metamorphosed in amphibolite and greenschist facies. K/Ar determinations on amphibole and mica yielded isotopic ages of approx 40 m.y. (Authors' abstract)-A.W.H. 
81; contact aureole; ophiolite; Palawan Island; petrochemistry; petrography; Philippines; structures