Petrogenesis of olivine-phyric basalts from the Aphanasey Nikitin Rise; evidence for contamination by cratonic lower continental crust

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doi: 10.1093/petrology/42.2.277
Author(s): Borisova, A. Yu.; Belyatsky, B. V.; Portnyagin, M. V.; Sushchevskaya, N. M.
Author Affiliation(s): Primary:
Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow, Russian Federation
Université Libre de Bruxelles, Belgium
Universität Göttingen, Federal Republic of Germany
Institute of Precambrian Geology and Geochronology, Russian Federation
Volume Title: Journal of Petrology
Source: Journal of Petrology, 42(2), p.277-319. Publisher: Oxford University Press, Oxford, United Kingdom. ISSN: 0022-3530 CODEN: JPTGAD
Note: In English. 137 refs.; illus., incl. 5 tables, sketch maps
Summary: The parental magma of these late Cretaceous basalts in the Indian Ocean was a water-poor (0.3-0.5 wt.%) hypersthene-normative melt. The basalt suite has Nb, Ta, Th and U depletion and very low 206Pb/204Pb and 143Nd/144Nd. Modelling shows the suite to be derived from fractional crystallization of depleted mantle-derived melt with assimilation of lower Gondwanan continental crust, which had long-term Rb, U and Th depletion. Two groups of anomalous tholeiites, all formed 115-75 m.y. ago in the Indian Ocean, are distinguished: one with Th depletion and unradiogenic Pb and the second with Th enrichment and more radiogenic Pb and Sr. Major, trace and REE analyses of tholeiitic basalts, glasses, and trachybasalts are given plus isotopic Pb, Nd and Sr analyses.
Year of Publication: 2001
Research Program: ODP Ocean Drilling Program
Key Words: 03 Geochronology; 05 Petrology, Igneous and Metamorphic; Absolute age; Afanasiy Nikitin Rise; Basalts; Broken Ridge; Continental crust; Cratons; Cretaceous; Crust; Dates; Gondwana; Granulites; Igneous rocks; Indian Ocean; Kerguelen Plateau; Leg 119; Lower Cretaceous; Lower crust; Magma contamination; Mesozoic; Metamorphic rocks; Nd/Nd; ODP Site 738; Ocean Drilling Program; Olivine basalt; Pb/Pb; Sr/Sr; Tholeiite; Volcanic rocks
Coordinates: S624233 S624232 E0824715 E0824714
Record ID: 2001045414
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom