Geochemistry of Ontong Java Plateau basalts ...

• Main Authors: Mahoney, John J, Storey, Michael, Duncan, Robert A, Spencer, Khalil J, Pringle, Malcolm S
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1993
• Subjects: Drilling/drill rig; Leg30; Leg33; Leg130; Glomar Challenger; Joides Resolution; Deep Sea Drilling Project DSDP; Ocean Drilling Program ODP; Iceland
• Online Access: https://dx.doi.org/10.1594/pangaea.779581; https://doi.pangaea.de/10.1594/PANGAEA.779581

Basement rocks from the Ontong Java Plateau are tholeiitic basalts that appear to record very high degrees of partial melting, much like those found today in the vicinity of Iceland. They display a limited range of incompatible element and isotopic variation, but small differences are apparent between sampled sites and between upper and lower groups of flows at Ocean Drilling Program Site 807.40Ar-39Ar ages of lavas from Site 807 and Deep Sea Drilling Project Site 289 are indistinguishable about an early Aptian mean of 122 Ma (as are preliminary data for the island of Malaita at the southern edge of the plateau), indicating that plateau-building eruptions ended more or less simultaneously at widely separated locations. Pb-Nd-Sr isotopes for lavas from Sites 289, 803, and 807, as well as southern Malaita, reflect a hotspot-like source with epsilon-Nd(T) = +4.0 to +6.3, (87Sr/86Sr)T = 0.70423-0.70339, and 206Pb/204Pb = 18.245-18.709 and possessing consistently greater 208Pb/204Pb for a given 206Pb/204Pb than ... : Supplement to: Mahoney, John J; Storey, Michael; Duncan, Robert A; Spencer, Khalil J; Pringle, Malcolm S (1993): Geochemistry and geochronology of Leg 130 basement lavas: Nature and origin of the Ontong Java Plateau. In: Berger, WH; Kroenke, LW; Mayer, LA; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 130, 3-22 ...