Tethyan ophiolites and Tethyan seaways

Abstract

Tethyan ophiolites have played a major role in the development of the ophiolite concept during the past 200 years, and contributed significantly to the formulations of the suprasubduction-zone (SSZ) ophiolite paradigm and the plate-tectonics theory. Their melt evolution and magmatic construction witnessed the dispersal of the supercontinent Pangaea via continental rifting and seafloor spreading, opening and closure of multiple seaways in an eastward widening, latitudinal ocean basin (Neotethys), and deep mantle recycling processes through subduction-zone tectonics and plume activities. Neotethyan ophiolites are highly diverse in their crustal–mantle structures and compositions, pointing to major differences in their melt sources and tectonic settings of magmatic construction. The papers in this thematic set demonstrate these differences in the Neotethyan ophiolite record through new structural, geochemical, isotopic and geochronological data and interpretations. The Jurassic Western Alpine Ophiolites formed in a narrow basin (Alpine Tethys) that developed between Europe and North Africa–Adria–Iberia. Their peridotites represent exhumed, continental lithospheric mantle. The Triassic, Jurassic and Cretaceous ophiolites east of Adria formed in different Neotethyan seaways, and their SSZ magmatic construction involved multiple episodes of melting, depletion and refertilization of subduction-modified oceanic mantle. The Late Cretaceous peri-Arabian and peri-Indian ophiolites, which are discontinuously exposed along a c. 9000 km long belt from SW Anatolia to SE Tibet, formed above a Trans-Tethyan subduction–accretion system within Southern Neotethys. Diachronous collisions of Arabia and India with this intraoceanic subduction–accretion system in the latest Mesozoic and the Paleogene (respectively) resulted in diachronous ophiolite emplacement in the Mediterranean and Tibetan–Himalayan orogenic belts. Thematic collection: This article is part of the ‘Tethyan ophiolites and Tethyan seaways collection’ available at: https://www.lyellcollection.org/cc/tethyan-ophiolites-and-tethyan-seaways