Geology, Geochemistry and U-Pb SHRIMP Age of the Tacloban Ophiolite Complex, Leyte Island (Central Philippines): Implications for the Existence and Extent of the Proto-Philippine Sea Plate |
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| Authors: | Leilanie O Suerte Graciano P Yumul Jr Rodolfo A Tamayo Jr Carla B Dimalanta Mei-Fu Zhou René C Maury Mireille Polvé Cesar L Balce |
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| Institution: | National Institute of Geological Sciences, college of Sceince, University of the Philippines, 1101 Diliman, Quezon City, Philippines;Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, People's Republic of China;Département des Sciences de la Terre, Universitéde Bretagne Occidentale, 6 av. he Gorgeu, B.P. 809, F-29285 Brest, France;UMR 6538, UniversitéPaul Sabatier, 38, rue des 36 Ponts, 31400 Toulouse, France;Mines and Geosciences Bureau Region - 8, Department of Environment and Natural Resources, Tacloban City, Leyte, Philippines;Mines and Geosciences Bureau Region - 6, Department of Environment and Natural Resources, Iloilo City, Philippines;Philippine Council for Industry Energy Research and Development, Department of Science and Technology, Bicutan, Taguig, Philippines |
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| Abstract: | Abstract. The oceanic basement of the Central Philippines is exposed in ophiolitic massifs the age and origin of which remain debated. The Tacloban Ophiolite Complex (TOC) outcrops as a NW-SE trending massif in the northeastern portion of Leyte Island, Central Philippines. It is unconformably overlain by sedimentary sequences dated to Late Miocene-Pliocene and Pleistocene volcaniclastic deposits on its eastern and western flanks, respectively. Field, petrographic and trace element data suggest a subduction-related origin for this ophiolite. Sensitive High Resolution Ion Microprobe (SHRIMP) U-Pb dating of zircons from a gabbro yielded Early Cretaceous magmatic age for the TOC, which is very much older than a previously reported whole rock K-Ar derived Eocene age. The Early Cretaceous age of the TOC limits its possible progenitor to the proto-Philippine Sea Plate. Correlation with other Cretaceous ophiolites in Central Philippines reveals the possible extent of the proto-Philippine Sea Plate remnants now exposed onland. |
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| Keywords: | ophiolite U-Pb SHRIMP geochemistry proto-Philippine Sea Plate Leyte Philippines |
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