Tethyan ophiolite emplacement, Africa to Europe motions, and Atlantic spreading
Published:January 01, 2006
A. G. Smith, 2006. "Tethyan ophiolite emplacement, Africa to Europe motions, and Atlantic spreading", Tectonic Development of the Eastern Mediterranean Region, A. H. F. Robertson, D. Mountrakis
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Final emplacement of the mid-Jurassic and mid-Cretaceous supra-subduction zone (SSZ) ophiolites onto adjacent continental areas in the Mediterranean region is synchronous with reductions in the rate of motion between Africa and stable Europe. The Apennine–Ligurian–Alpine ophiolites lack SSZ chemistry, are mid-ocean ridge basalt (MORB)-like, range in age from c. 169 to 148 Ma, and were emplaced in late Cretaceous and Cenozoic time. The Hellenic–Dinaric SSZ ophiolites include some MORB, ranging from 173 to 168 Ma, and were emplaced, eroded, and covered by younger sediments by c. 140 Ma. The creation of the Apennine–Ligurian–Alpine and Hellenic–Dinaric suites is attributed to the motion of Adria, which formed a promontory on Africa, or essentially moved with it, as the central Atlantic opened. Extension to the west of Adria gave rise to the Ligurian Sea, generating MORB crust; to the east, a pre-existing Triassic ocean was subducted, with rollback creating Jurassic SSZ ophiolites that were emplaced onto adjacent continental margins in the later stages of convergence. The two episodes of slower motions between Africa and Europe are attributed to two episodes of attempted subduction of a passive continental margin. This speculation suggests that emplacement of some SSZ ophiolites may exert a significant control on oceanic spreading patterns.
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Tectonic Development of the Eastern Mediterranean Region
The Eastern Mediterranean region is a classic area for the study of tectonic processes and settings related to the development of the Tethyan orogenic belt. The present set of research and synthesis papers by Earth scientist from countries in this region and others provides an up-to-date, interdisciplinary overview of the tectonic development of the Eastern Mediterrenean region from Precambrian to Recent. Key topics include continental rifting, ophiolite genesis and emplacement, continental collision, extensional tectonics, crustal exhumation and intraplate deformation (e.g. active faulting). Alternative tectonic reconstructions of the Tethyan orogen are presented and discussed, with important implications for other regions of the world. The book will be an essential source of information and interpretation for academic researchers (geologists and geophysicists), advanced undergraduates and also for industry professionals, including those concerned with hydrocarbons, minerals and geological hazards (e.g. earthquakes).