230Th-238U disequilibrium in East Scotia back-arc basalts: implications for slab contribution and flux rates.

Fretzdorff, Susanne, Haase, Karsten, Leat, P. T., Livermore, R. A., Garbe-Schönberg, C.-Dieter, Fietzke, Jan and Stoffers, Peter (2003) 230Th-238U disequilibrium in East Scotia back-arc basalts: implications for slab contribution and flux rates. Geology, 31 (8). pp. 693-696. DOI 10.1130/G19469.1.

[img] Text
Fretzdorff.pdf - Reprinted Version
Restricted to Registered users only

Download (425Kb)

Supplementary data:

Abstract

New U-series isotope data for lavas from the East Scotia backarc spreading center span a large range in (230Th/232Th) and (238U/232Th). Most of the backarc lavas have (238U/230Th) < 1, similar to the composition of mid-oceanic-ridge basalts (MORB). Lavas from two segments have (238U/230Th) > 1 and are enriched in fluid-mobile elements, implying a recent addition of a U-rich slab-derived component. The data from one segment suggest an influence from an aqueous fluid from altered MORB, whereas samples from the other slab-influenced segment show addition of a sediment melt. The slab-influenced samples form a distinct trend in the equiline diagram between aqueous fluid and sediment melt that is suggested to be a mixing line rather than an isochron.

Document Type: Article
Keywords: East Scotia Ridge, backarc, U-series isotopes, aqueous fluids, sediment melts
Research affiliation: Kiel University
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1130/G19469.1
ISSN: 0091-7613
Date Deposited: 18 Feb 2008 17:26
Last Modified: 26 Sep 2017 07:58
URI: http://oceanrep.geomar.de/id/eprint/5126

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...