Dating the subduction of the Arabian continental margin beneath the Semail ophiolite, Oman

Journal article

The presence of high-pressure (P) eclogites along the northeast margin of the Arabian continental plate beneath the Semail ophiolite demonstrates that subduction of thinned continental crust to pressures of 20 kbar (∼80 km depth) has occurred. Current debate centers on whether this high-P metamorphism occurred prior to, during, or following ophiolite emplacement, which is known to have started ca. 95-93 Ma. Five concordant U-Pb zircon ages from a garnet-clinopyroxene-phengite-crossite eclogite from As Sifah, northeast Oman, precisely constrain the age of high-P metamorphism at 79.1 ± 0.3 Ma. This age demonstrates that high-P metamorphism occurred during continental subduction 15 m.y. after formation of the ocean floor that subsequently became the Semail ophiolite.

Authors: Warren, C; Parrish, R; Searle, M; Waters, D

• Publication status: Published
• Journal: GEOLOGY
• Volume: 31
• Issue: 10
• Pages: 889-892
• Publication date: 2003-10-01
• DOI: 10.1130/G19666.1
• ISSN: 0091-7613
• Language: English
• Keywords: U-Pb geochronology; eclogites; subduction; Oman ophiolite; Arabian margin