Geochemistry of lavas from the Ahu and Tupa volcanic fields, Easter Hotspot, southeast Pacific: Implications for intraplate magma genesis near a spreading axis.

Haase, K. M. and Devey, Colin W. (1996) Geochemistry of lavas from the Ahu and Tupa volcanic fields, Easter Hotspot, southeast Pacific: Implications for intraplate magma genesis near a spreading axis. Earth and Planetary Science Letters, 137 (1-4). pp. 129-143. DOI 10.1016/0012-821X(95)00217-Z.

[img] Text
1-s2.0-0012821X9500217Z-main.pdf - Published Version
Restricted to Registered users only

Download (1726Kb)

Supplementary data:

Abstract

Lavas from two young volcanic fields of the Easter Hotspot consist mainly of enriched tholeiites, with incompatible element and isotopic compositions similar to enriched MORB from the neighbouring spreading axis. The major element composition of these intraplate tholeiites suggests that they originate from melting at greater pressures, and REE models indicate slightly lower degrees of partial melting than beneath the ridge. This can be explained by the thickening of the lithosphere away from the spreading axis, accompanied by increasing mantle temperature as the Easter plume is approached. These processes combine to depress the melting zone to greater depth in the intraplate region. The relatively low degrees of partial melting and low volumes of melt compared, for example, to Galapagos imply a low excess temperature (∼ 100°C?) for the Easter plume. A few depleted tholeiites found on the Ahu volcanic field were generated by shallow melting of an extremely depleted (more depleted than MORB

Document Type: Article
Keywords: hot spot; tholeiite; neodymium; rare earths; major elements
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1016/0012-821X(95)00217-Z
ISSN: 0012-821X
Date Deposited: 18 Feb 2008 17:23
Last Modified: 14 Nov 2016 13:59
URI: http://oceanrep.geomar.de/id/eprint/2495

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...