Reunion hotspot magma chemistry over the past 65 m.y.; results from Leg 115 of the Ocean Drilling Program

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doi: 10.1130/0091-7613(1989)017<0934:RHMCOT>2.3.CO;2
Author(s): Fisk, Martin R.; Duncan, Robert A.; Baxter, Alistair N.; Greenough, John D.; Hargraves, Robert B.; Tatsumi, Yoshiyuki; Backman, Jan; Baker, Paul A.; Boersma, Anne; Cullen, James L.; Droxler, André W.; Hempel, Peter; Hobart, Mike; Hurley, Michael; Johnson, David; Macdonald, Andrew H.; Mikkelsen, Naja; Okada, Hisatake; Peterson, Larry C.; Rio, Domenico; Robinson, Simon G.; Schneider, David; Swart, Peter K.; Vandamme, Didier; Vilkes, Gustav; Vincent, Edith
Ocean Drilling Program, Leg 115 Shipboard Scientific Party
Author Affiliation(s): Primary:
Oreg. State Univ., Coll. Oceanogr., Corvallis, OR, United States
Thames Polytech., United Kingdom
Mt. Allison Univ., Canada
Princeton Univ., United States
Kyoto Univ., Japan
Volume Title: Geology (Boulder)
Source: Geology (Boulder), 17(10), p.934-937. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0091-7613 CODEN: GLGYBA
Note: In English. 25 refs.; illus. incl. 1 table, sketch map
Summary: Leg 115 of the Ocean Drilling Program recovered basalts from four locations along the hotspot track that leads from the Deccan flood basalts in India to Reunion Island in the western Indian Ocean (Sites 706, 707, 713, and 715). The drilled basalts range in age from 35 Ma (Site 706) to 64 Ma (Site 707), and including the Deccan basalts (66 to 68 Ma), Mauritius Island (0.2 to 8 Ma), and Reunion Island (0 to 2 Ma), seven sites are provided for sampling the volcanic record of the 5000-km-long hotspot track. Chemical and age comparisons indicate that Site 707 lavas correlate with basalt units near the top of the Deccan flood basalt sequence. The lavas of Site 715 (55 to 60 Ma) are most similar to the islands of Mauritius and Reunion. Site 713 basalts (48 Ma) are similar to the earliest lavas of the Deccan province, and Site 706 basalts are intermediate in chemistry between those of central Indian spreading-ridge basalts and Reunion. Differences in lava compositions along the hotspot track can be related to variable mixing of plume and asthenospheric mantle, depending on the changing position of spreading-ridge segments and the hotspot during the opening of the Indian Ocean. Alternatively, time-dependent changes in the composition of hotspot melts may be due to a decrease in partial melting of a heterogeneous plume or to intrinsic changes in the composition of material supplied by the plume.
Year of Publication: 1989
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 05 Petrology, Igneous and Metamorphic; 18 Geophysics, Solid-Earth; Asthenosphere; Basalts; Cenozoic; Cores; Geochemistry; Hot spots; Hybridization; Igneous activity; Igneous rocks; Indian Ocean; Indian Ocean Islands; Lava; Leg 115; Magmas; Major elements; Mantle; Mantle plumes; Mascarene Islands; ODP Site 706; ODP Site 707; ODP Site 713; ODP Site 715; Ocean Drilling Program; Partial melting; Plate tectonics; Reunion; Sea-floor spreading; Trace elements; Volcanic rocks; Western Indian Ocean
Coordinates: S150000 N080000 E0800000 E0550000
Record ID: 1989069800
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