Geochemical heterogeneity in the Hawaiian plume : constraints from Hawaiian volcanoes and Emperor seamounts

The 6000-km long, age-progressive linear Hawaii-Emperor Chain is one of the best defined hotspot tracks. This hotspot track plays an important role in the plume hypothesis. In this research, geochemical data on the Hawaiian-Emperor lavas are used to evaluate the plume hypothesis. There are important geochemical similarities among lavas from the Hawaii-Emperor Chain, such as high Ba/Th (>100), high ³He/⁴He (>10 R/R-A) and enrichment in incompatible elements. These distinctive geochemical characteristics are not present in mid-ocean ridge basalt (MORB). Consequently, it is inferred that a common mantle source has been contributing to the Hawaiian-Emperor volcanism for over 80 My, which provides the strongest geochemical argument supporting the plume hypothesis. The distinctive geochemical characteristics of Makapuu-stage Koolau lavas, such as high SiO₂ content, ⁸⁷Sr/⁸⁶Sr, ²⁰⁸Pb*/²⁰⁶Pb*, [delta]¹⁸0, ¹⁸⁷Os/¹⁸⁸Os, La/Nb, Sr/Nb and low CaO content, ¹⁴³Nd/¹⁴⁴Nd, ²⁰⁶Pb/²⁰⁴Pb, Th/La, require that recycled ancient oceanic crust including sediments is present in the Hawaiian plume. Some of these distinctive geochemical characteristics are also present in other Hawaiian shields. For example, Kahoolawe lavas also range to low ²⁰⁶Pb/²⁰⁴Pb.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Earth, Atmospheric, and Planetary Sciences.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Huang, Shichun

Advisor dc:contributor.advisor

• Frederick A. Frey.

• Earth, Atmospheric, and Planetary Sciences.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/33947
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/33947

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/33947