Plume versus plate origin for the Shatsky Rise oceanic plateau (NW Pacific); insights from Nd, Pb and Hf isotopes

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doi: 10.1016/j.lithos.2014.03.031
Author(s): Heydolph, Ken; Murphy, David T.; Geldmacher, Jörg; Romanova, Irina V.; Greene, Andrew; Hoernle, Kaj; Weis, Dominique; Mahoney, John
Author Affiliation(s): Primary:
Helmholtz Centre for Ocean Research, Kiel, Germany
Queensland University of Technology, Australia
Hawaii Pacific University, United States
University of Hawaii at Manoa, United States
University of British Columbia, Canada
Volume Title: Lithos (Oslo)
Source: Lithos (Oslo), Vol.200-201, p.49-63. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0024-4937 CODEN: LITHAN
Note: In English. Includes appendices. 130 refs.; illus., incl. 1 table, sketch map
Summary: Shatsky Rise, an early Cretaceous igneous oceanic plateau in the NW Pacific, comprises characteristics that could be attributed to either formation by shallow, plate tectonic-controlled processes or to an origin by a mantle plume (head). The plateau was drilled during Integrated Ocean Drilling Program (IODP) Expedition 324. Complementary to a recent trace element study (Sano et al., 2012) this work presents Nd, Pb and Hf isotope data of recovered lava samples cored from the three major volcanic edifices of the Shatsky Rise. Whereas lavas from the oldest edifice yield fairly uniform compositions, a wider isotopic spread is found for lavas erupted on the younger parts of the plateau, suggesting that the Shatsky magma source became more heterogeneous with time. At least three isotopically distinct components can be identified in the magma source: 1) a volumetrically and spatially most common, moderately depleted component of similar composition to modern East Pacific Ridge basalt but with low 3He/4He, 2) an isotopically very depleted component which could represent local, early Cretaceous (entrained) depleted upper mantle, and 3) an isotopically enriched component, indicating the presence of (recycled) continental material in the magma source. The majority of analyzed Shatsky lavas, however, possess Nd-Hf-Pb isotope compositions consistent with a derivation from an early depleted, non-chondritic reservoir. By comparing these results with petrological and trace element data of mafic volcanic rock samples from all three massifs (Tamu, Ori, Shirshov), we discuss the origin of Shatsky Rise magmatism and evaluate the possible involvement of a mantle plume (head). Abstract Copyright (2014) Elsevier, B.V.
Year of Publication: 2014
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 05 Petrology, Igneous and Metamorphic; Basalts; Cretaceous; East Pacific; East Pacific Rise; Expedition 324; Hafnium; ICP mass spectra; IODP Site U1346; IODP Site U1347; IODP Site U1350; Igneous rocks; Integrated Ocean Drilling Program; Isotope ratios; Isotopes; Lead; Leg 191; Leg 198; Lower Cretaceous; Magmas; Magmatism; Mantle plumes; Mass spectra; Mesozoic; Metals; Neodymium; North Pacific; Northwest Pacific; ODP Site 1179; ODP Site 1213; Ocean Drilling Program; Oceanic plateaus; Ori Massif; Pacific Ocean; Plate tectonics; Rare earths; Shatsky Rise; Shirshov Massif; Spectra; Tamu Massif; Triple junctions; Volcanic rocks; Volcanism; West Pacific
Coordinates: N323000 N380100 E1623900 E1582700
Record ID: 2014069231
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands