The early Miocene (∼25 Ma) volcanism in the northern Kyushu-Palau Ridge, enriched mantle source injection during rifting prior to the Shikoku back-arc basin opening

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doi: 10.1007/s00410-011-0680-x
Author(s): Haraguchi, Satoru; Ishii, Teruaki; Kimura, Jun-Ichi; Kato, Yasuhiro
Author Affiliation(s): Primary:
University of Tokyo, Atmosphere and Ocean Research Institute, Kashiwa, Japan
Other:
Fukada Geological Institute, Japan
Japan Agency for Marine Earth Science and Technology, Japan
Volume Title: Contributions to Mineralogy and Petrology
Source: Contributions to Mineralogy and Petrology, 163(3), p.483-504. Publisher: Springer International, Heidelberg - New York, International. ISSN: 0010-7999 CODEN: CMPEAP
Note: In English. Includes appendices. 81 refs.; illus., incl. 2 tables, sketch maps
Summary: The northern Kyushu-Palau Ridge (KPR), remnant conjugate arc of the Izu-Ogasawara (Bonin)-Mariana (IBM) active arc, is dominated by basalt-andesite except for the Komahashi-Daini Seamount where acidic plutonic rocks of 38 Ma were recovered. These mafic to intermediate volcanics are produced by the rifting volcanism in the proto-IBM arc associated with spreading of the Shikoku Basin. The HFSE and HREE contents and ratios of these volcanics indicate enriched source mantle composition compared to recent volcanic front. The LILE ratios exhibit similar characteristics to reararc volcanism of the recent Izu arc, and some enriched volcanics exhibit high abundance of sediment melt inputs. Based on these observations and compilations of the published data set, the replacement event of the wedge mantle under the IBM arc occurred two times. The first event occurred between 45 and 38 Ma, with Pacific type mantle being replaced by depleted Indian type mantle. The second event occurred between 36 and 25 Ma, enriched mantle flowed from reararc side. The slab component during the proto-IBM arc rifting was a similar characteristic to recent reararc volcanism of the Izu arc, and sediment melt added in a local area. Copyright 2011 Springer-Verlag
Year of Publication: 2012
Research Program: ODP Ocean Drilling Program
Key Words: 05 Petrology, Igneous and Metamorphic; 18 Geophysics, Solid-Earth; Andesites; Back-arc basins; Basalts; Basins; Cenozoic; Chemical composition; Enrichment; Geochemistry; ICP mass spectra; Igneous rocks; Izu-Bonin Arc; Komahashi-Daini Seamount; Kyushu-Palau Ridge; Leg 126; Lithophile elements; Lithosphere; Lower Miocene; Major elements; Mantle; Mantle wedges; Mass spectra; Metasomatism; Mid-ocean ridge basalts; Miocene; Neogene; North Pacific; Northwest Pacific; ODP Site 793; Ocean Drilling Program; Ocean floors; Oceanic lithosphere; Pacific Ocean; Parece Vela Basin; Petrology; Philippine Sea; Philippine Sea Plate; Plate tectonics; Plutonic rocks; Rift zones; Rifting; Sea-floor spreading; Seamounts; Shikoku Basin; Spectra; Spreading centers; Tertiary; Trace elements; Volcanic rocks; Volcanism; West Pacific; X-ray fluorescence spectra
Coordinates: N310619 N310621 E1405217 E1405215
N110000 N200000 E1370000 E1340000
Record ID: 2012047433
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by Springer Verlag, Berlin, Federal Republic of Germany