Document
Geochronological constraints on the metamorphic sole of the Semail ophiolite in the United Arab Emirates.
Identifier
DOI: 10.1016/j.gsf.2015.12.003
Contributors
Thomas, Robert J., Author
Jacobs, Joachim., Author
Publisher
Elsevier.
Gregorian
2016-07
Language
English
Subject
English abstract
The Semail ophiolite of Oman and the United Arab Emirates (UAE) provides the best preserved large slice of oceanic lithosphere exposed on the continental crust, and offers unique opportunities to study processes of ocean crust formation, subduction initiation and obduction. Metamorphic rocks exposed in the eastern UAE have traditionally been interpreted as a metamorphic sole to the Semail ophiolite. However, there has been some debate over the possibility that the exposures contain components of older Arabian continental crust. To help answer this question, presented here are new zircon and rutile U-Pb geochronological data from various units of the metamorphic rocks. Zircon was absent in most samples. Those that yielded zircon and rutile provide dominant single age populations that are 95-93 Ma, partially overlapping with the known age of oceanic crust formation (96.5-94.5 Ma), and partially overlapping with cooling ages of the metamorphic rocks (95-90 Ma). The data are interpreted as dating high-grade metamorphism during subduction burial of the sediments into hot mantle lithosphere, and rapid cooling during their subsequent exhumation. A few discordant zircon ages, interpreted as late Neoproterozoic and younger, represent minor detrital input from the continent. No evidence is found in favour of the existence of older Arabian continental crust within the metamorphic rocks of the UAE.
Member of
ISSN
1674-9871
Resource URL
Category
Journal articles