caa a22 4500 606149996 CHVBK 20210128100536.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00531-015-1151-9 doi (NATIONALLICENCE)springer-10.1007/s00531-015-1151-9 The Hyblean xenolith suite (Sicily): an unexpected legacy of the Ionian-Tethys realm [Elektronische Daten] [Fabio Manuella, Vittorio Scribano, Serafina Carbone, Alfonso Brancato] The extensive study of a great number of deep-seated xenoliths from Tortonian tuff-breccia pipes in the Hyblean area (Sicily) revealed the following fundamental evidence: (1) typical continental crust rocks are completely absent in the entire xenolith suite; (2) mantle ultramafics are more abundant than gabbroids; (3) sheared oxide-gabbros, closely resembling those from oceanic fracture zones, are relatively common; (4) secondary mineral assemblages, compatible with alteration processes in serpentinite-hosted hydrothermal systems, occur both in peridotites and gabbros. Among the products of this hydrothermal activity, organic compounds, having abiotic origin via Fischer-Tropsch synthesis, occur in some hydrothermally altered gabbro and ultramafic xenoliths, as well as in hydrothermal clays. Moreover, the U-Pb dating of hydrothermal zircon grains, hosted in a xenolith of metasomatized tectonic breccia, indicated an Early-Middle Triassic age of the fossil hydrothermal system. Another line of evidence for the oceanic nature of the Hyblean-Pelagian basement is the complete absence of continental crust lithologies (granites, felsic metaigneous, and metasedimentary rocks) in outcrops and in boreholes, and the oceanic affinity of the Tertiary volcanic rocks from the Hyblean Plateau and the Sicily Channel (Pantelleria and Linosa Islands), which lack of any geochemical signature for continental crust contamination. A reappraisal of existing geophysical data pointed out that serpentinites form the dominant lithologies in the lithospheric basement of the Hyblean-Pelagian area down to a mean depth of 19km, which represents the regional Moho considered as the serpentinization front, marking the transition from serpentinites to unaltered peridotites. On these grounds, we confirm that Hyblean xenoliths contain mineralogical, compositional, and textural evidence for tectonic, magmatic, and hydrothermal processes indicating the existence of fossil oceanic core complexes, in the geotectonic framework of the Paleo-Mesozoic, ultra-slow spreading, Ionian-Tethys Ocean forming the present Ionian-Hyblean-Pelagian domain. Springer-Verlag Berlin Heidelberg, 2015 Serpentinites nationallicence Volcanic rocks nationallicence Xenoliths nationallicence Hydrocarbons nationallicence Permian Tethys nationallicence Hyblean Plateau nationallicence Manuella Fabio Via Dell'Oro 137, 95123, Catania, Italy aut Scribano Vittorio Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Sezione di Scienze della Terra, Università di Catania, 95129, Catania, Italy aut Carbone Serafina Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Sezione di Scienze della Terra, Università di Catania, 95129, Catania, Italy aut Brancato Alfonso Istituto Nazionale di Geofisica e Vulcanologia-Osservatorio Etneo, 95123, Catania, Italy aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/5(2015-07-01), 1317-1336 1437-3254 104:5<1317 2015 104 531 https://doi.org/10.1007/s00531-015-1151-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 review-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-015-1151-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Manuella Fabio Via Dell'Oro 137, 95123, Catania, Italy aut NATIONALLICENCE 700 1- Scribano Vittorio Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Sezione di Scienze della Terra, Università di Catania, 95129, Catania, Italy aut NATIONALLICENCE 700 1- Carbone Serafina Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Sezione di Scienze della Terra, Università di Catania, 95129, Catania, Italy aut NATIONALLICENCE 700 1- Brancato Alfonso Istituto Nazionale di Geofisica e Vulcanologia-Osservatorio Etneo, 95123, Catania, Italy aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/5(2015-07-01), 1317-1336 1437-3254 104:5<1317 2015 104 531