CaltechAUTHORS
  A Caltech Library Service

Solidus curves, mantle plumes, and magma generation beneath Hawaii

Wyllie, Peter J. (1988) Solidus curves, mantle plumes, and magma generation beneath Hawaii. Journal of Geophysical Research B, 93 (B5). pp. 4171-4181. ISSN 0148-0227. http://resolver.caltech.edu/CaltechAUTHORS:20141105-135152446

[img]
Preview
PDF - Published Version
See Usage Policy.

1212Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20141105-135152446

Abstract

The eruption of nepheline-normative lavas in the early and late stages of formation of the large Hawaiian tholeiite shields is well established, as is the conclusion that volatile components are involved in the genesis of these alkaline lavas. For magmas to be generated, the source materials must be transported across their solidus curves. Solidus curves for volatile-free peridotite and for peridotite-C-H-O provide the depth-temperature framework for the sites of magma generation. The assumption (controversial) that garnet remains in the source material locates the major melting region in plume material at depths of about 80 km, with isotherms in plume center exceeding 1500°C. The plume carries traces of volatile components from depths greater than 300 km. These dissolve in a trace of interstitial melt as the plume crosses the solidus for peridotite-C-H-O at depths decreasing from 350 km to about 150 km with distance from the plume axis. The volatile-charged melt, enriched in incompatible elements, is swamped by the picrites generated in the major melting region. From the outer portions of the plume, the volatile-rich melt enters the lithosphere at 80–90 km depth, where the change in rheology retards its upward percolation. This magma (remaining in equilibrium with peridotite) is carried toward the solidus for peridotite-C-H-O, changing composition toward nephelinite; evolution of vapor as magma approaches the solidus may facilitate intermittent crack propagation, releasing the nephelinitic magmas for eruption from depths of 75–85 km. Movement of the lithosphere plate over the rising plume establishes asymmetry. Eruption of nephelinitic magmas on the upstream side of the plume (early volcanism) may be suppressed or very close in time and space to eruption of alkaline lavas and tholeiites. On the downstream side (late volcanism), eruption of nephelinites is delayed by lateral transport away from the main melting region.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1029/JB093iB05p04171DOIArticle
http://onlinelibrary.wiley.com/doi/10.1029/JB093iB05p04171/abstractPublisherArticle
Additional Information:Copyright 1988 by the American Geophysical Union. (Received May 18, 1987; revised November 20, 1987; accepted November 23, 1987.) Paper number 7B7076. This research was supported by the Earth Science Section of the National Science Foundation, grant EAR84-16583. For assistance during the preparation of the paper and for reviews, I thank D. L. Anderson, G. B. Dalrymple, S. M. Eggins, D. H. Eggler, F. A. Frey, D. H. Green, B. H. Hager, O. Navon, D. C. Presnall, E. M. Stolper, W. R. Taylor, and T. L. Wright, noting that thy are not responsible for shortcomings or errors in the final version of the article. Caltech Division of Geological and Planetary Sciences contribution 4562.
Funders:
Funding AgencyGrant Number
NSFEAR84-16583
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Division of Geological and Planetary Sciences4562
Record Number:CaltechAUTHORS:20141105-135152446
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20141105-135152446
Official Citation:Wyllie, P. J. (1988), Solidus curves, mantle plumes, and magma generation beneath Hawaii, J. Geophys. Res., 93(B5), 4171–4181, doi:10.1029/JB093iB05p04171.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:51323
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:05 Nov 2014 22:20
Last Modified:05 Nov 2014 22:20

Repository Staff Only: item control page