Rare earth element and related chemistry of some drilled southern Indian Ocean basalts and volcanogenic sediments

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doi: 10.1029/JB081i023p04257
Author(s): Fleet, A. J.; Henderson, P.; Kempe, D. R. C.
Volume Title: Journal of Geophysical Research
Source: Journal of Geophysical Research, 81(23), p.4257-4268. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0148-0227 CODEN: JGREA2
Note: In English; illus. incl. tables, sketch map
Summary: The rare earth elements (REE), selected incompatible elements, and overall compositions of some Deep-Sea Drilling Project (DSDP) leg 26 (southern Indian Ocean) basalts and volcanogenic sediments are reported. Variations in REE distributions are not always relatable to existing tectonic features that characterize the sampled sites. The olivine-rich basalt at site 250 is transitional between midocean ridge basalt (Morb) and alkali basalt and is tentatively considered to have been produced by hot spot activity. The age relationships of site 257 basalts are not clear, but the uppermost unit (flow?) has a distinct light REE and incompatible element enrichment and is apparently very much younger than the lower units, which show light REE depletion. Like the basalts, the volcanogenic sediments of Ninety East Ridge (sites 253 and 254) and Naturaliste Plateau (site 258) are enriched in light relative to heavy REE. Alteration seems to have little effect on the REE abundances except for the high La/Ce ratio. In the volcanogenic sediments it may result from an admixture of Ce-poor biogenic calcite. Site 256 and uppermost 257 basalts from the Wharton Basin may have been derived from the same single source as the rocks forming the Ninety East Ridge, Naturaliste Plateau, Broken Ridge, Kerguelen Plateau, and Amsterdam-Saint Paul islands.
Year of Publication: 1976
Research Program: DSDP Deep Sea Drilling Project
Key Words: 02 Geochemistry; Abundance; Amsterdam Island; Basalts; Broken Ridge; Cerium; Chemical composition; Clastic rocks; Composition; DSDP Site 250; DSDP Site 253; DSDP Site 254; DSDP Site 256; DSDP Site 257; DSDP Site 258; Deep Sea Drilling Project; Europium; Faults; Geochemistry; Hot spots; Igneous rocks; Indian Ocean; Indian Ocean Islands; Interpretation; Lanthanum; Leg 26; Lutetium; Mantle; Mantle plumes; Metals; Naturaliste Plateau; Neodymium; Ninetyeast Ridge; Plate tectonics; Pyroclastics; Rare earths; Saint Paul Island; Samarium; Sedimentary rocks; South; Structure; Terbium; Transform; Volcanic rocks; Wharton Basin; Ytterbium
Record ID: 1977005237
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.

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