Geochemistry and trace elements at DSDP Hole 78-543A

The upper part of the basaltic substratum of the Atlantic abyssal plain, approaching subduction beneath the Barbados Ridge and thus presumably beneath the Lesser Antilles island arc, is made of typical LREE-depleted oceanic tholeiites. Mineralogical (microprobe) and geochemical (X-ray fluorescence,...

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Bibliographic Details
Main Authors: Bougault, Henri, Joron, Jean Louis, Maury, R C, Bohn, Marcel, Tardy, M, Biju-Duval, Bernard
Format: Dataset
Language:English
Published: PANGAEA 1984
Subjects:
78-543A
Deep Sea Drilling Project
DRILL
Drilling/drill rig
DSDP
Glomar Challenger
Leg78
Leg78AB
North Atlantic/CONT RISE
Mid-Atlantic Ridge
North Atlantic
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.808824
https://doi.org/10.1594/PANGAEA.808824
Description
Summary:The upper part of the basaltic substratum of the Atlantic abyssal plain, approaching subduction beneath the Barbados Ridge and thus presumably beneath the Lesser Antilles island arc, is made of typical LREE-depleted oceanic tholeiites. Mineralogical (microprobe) and geochemical (X-ray fluorescence, neutron activation analyses) data are given for 12 samples from the bottom of Hole 543A, which is 3.5 km seaward of the deformation front of the Barbados Ridge complex. These basalts are overlain by a Quaternary to Maestrichtian-Campanian sedimentary sequence. Most of the basalts are relatively fresh (in spite of the alteration of olivine and development of some celadonite, clays, and chlorite in their groundmass), and their mineralogical and geochemical compositions are similar to those of LREE-depleted recent basalts from the Mid-Atlantic Ridge. The most altered samples occur at the top of the basaltic sequence, and show trends of enrichment in alkali metals typical of altered oceanic tholeiites.

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