Oxygen isotope constraints on the petrogenesis of volcanic arc magmas from Martinique, Lesser Antilles

Details Oxygen isotope constraints on the petrogenesis of volcanic arc magmas from Martinique, Lesser Antilles Oxygen isotope constraints on the petrogenesis of volcanic arc magmas from Martinique, Lesser Antilles

Nov 1989

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1989e%26psl..95..255d&link_type=abstract

Earth and Planetary Science Letters, Volume 95, Issue 3-4, p. 255-270.

Other

19

Scientific paper

Volcanic rocks from the island of Martinique in the Lesser Antilles island arc are highly diverse isotopically. Values of δ18O (‰ SMOW) in lavas erupted over the last 5 Ma from five stratigraphically discrete and geochemically distinct volcanic centers are: Morne Jacob = +7.5 to +7.9‰ Pitons du Carbet = +8.0 to +8.9‰ Diamant = +6.3 to +7.4‰ Piton Mt. Conil, +7.2 to +7.3‰, and Mt. Pelée = +6.5 to +7.4‰. 13 of the 27 samples have been corrected for variable amounts of secondary alteration and low-temperature hydration. The least 18O-rich andesites on Martinique have δ18O values similar to those of the northern Lesser Antilles (δ18O = +6.0 to +7.3‰) and other intra-oceanic arcs like the Marianas (δ18O = +5.5 to +6.8‰). O-isotope ratios are compositionally dependent; correlations between δ18O and radiogenic isotope ratios (87Sr/86Sr, 143Nd/144Nd, 206Pb/204Pb) and indices of fractionation, show that modification of isotopic compositions occurred during magmatic differentiation rather than at source.
A two-stage model is proposed for the origin and differentiation of magmas on Martinique. Primary basaltic melts, which are broadly similar in composition to primitive island-arc magmas elsewhere (e.g. Marianas, Aleutians, South Sandwich Islands), are generated from the subduction-modified asthenospheric mantle wedge. These magmas ascend into the arc crust and differentiate. On Martinique, crystal fractionation is accompanied by contamination with isotopically distinct crust, including a component of terrigenous sediments. Thus, subduction-zone processes at the Lesser Antilles and other island arcs are similar, involving only a small (albeit significant isotopically) volumetric contribution from subducted sediment.
Present address: NERC Isotope Geology Center, 64 Gray's Inn Road, London WC1X 8NG, England, UK.

Affiliated with

Also associated with

No associations

Rating

Oxygen isotope constraints on the petrogenesis of volcanic arc magmas from Martinique, Lesser Antilles does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Oxygen isotope constraints on the petrogenesis of volcanic arc magmas from Martinique, Lesser Antilles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Oxygen isotope constraints on the petrogenesis of volcanic arc magmas from Martinique, Lesser Antilles will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1614315