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- Title
Chromite in the mantle section of the Oman ophiolite: A new genetic model.
- Authors
Rollinson, Hugh
- Abstract
This paper reviews the compositional data (major elements, platinum group element [PGE] concentrations, Os- and O-isotopes) for chromites from the mantle section of the Oman ophiolite. Chromites in chromitite from the Oman ophiolite lie on a compositional spectrum between high-Cr♯, boninite-like and low-Cr♯, mid-oceanic ridge basalt-like end-members. The high-Cr♯ end-member is low in Ti, has a fractionated PGE pattern and is enriched in iridium group-platinum group elements (IPGE). The low-Cr♯ end-member has higher Ti and an unfractionated PGE pattern. The compositional variation in the chromitites reflects their crystallization from a range of different melt compositions. It is proposed that this wide variation in melt compositions was produced by the process of a melt–rock reaction, whereby a basaltic melt has reacted with harzburgitic mantle to yield successively more Cr-rich melts. In contrast to previous models, this approach does not require a change in the tectonic environment to explain the different chromite types.
- Subjects
OMAN; CHROMITE; SPINEL group; OPHIOLITES; IGNEOUS rocks; REGOLITH
- Publication
Island Arc, 2005, Vol 14, Issue 4, p542
- ISSN
1038-4871
- Publication type
Article
- DOI
10.1111/j.1440-1738.2005.00482.x