Neogene volcanoes of Chios, Greece: The relative importance of subduction and back-arc extension

Pe-Piper, G; Piper, DJW; Kotopouli, CN; Panagos, AG

dc.contributor.author	Pe-Piper, G	en
dc.contributor.author	Piper, DJW	en
dc.contributor.author	Kotopouli, CN	en
dc.contributor.author	Panagos, AG	en
dc.date.accessioned	2014-03-01T01:42:40Z
dc.date.available	2014-03-01T01:42:40Z
dc.date.issued	1994	en
dc.identifier.issn	03058719	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/23885
dc.title	Neogene volcanoes of Chios, Greece: The relative importance of subduction and back-arc extension	en
heal.type	journalArticle	en
heal.identifier.primary	10.1144/GSL.SP.1994.081.01.12	en
heal.identifier.secondary	http://dx.doi.org/10.1144/GSL.SP.1994.081.01.12	en
heal.publicationDate	1994	en
heal.abstract	The Aegean area has experienced both extension and subduction throughout the Neogene and Quaternary. Small volcanic centres with a wide range of rock types occupy a 'back-arc' position with respect to the subduction zone, but their geochemistry and chronological correlation with local basin subsidence indicates that their origin is primarily the result of extension. The position of voluminous andesite-dacite volcanism in the modern south Aegean arc relative to the seismically defined Benioff zone is similar to that of other active subduction zones, although the timing of vigorous volcanic activity correlates with periods of most rapid basin subsidence. The voluminous early Miocene intermediate igneous rocks of the northeast Aegean also appear closely related to subduction. Variations in subduction-related products through time are correlated with changes in the rate and direction of subduction inferred from regional tectonic data. The island of Chios, in the eastern Aegean Sea, has several small, mid-Miocene (14-17 Ma) volcanic centres containing high-Mg calc-alkaline (adakitic) andesite, ne-normative basalt, and alkaline and calc-alkaline rhyolite. Both the ne-normative basalt and calc-alkaline andesite have Pb isotopic compositions similar to other Neogene volcanic rocks in the central Aegean region. The small size of the calc-alkaline centres (<10-1 km3) distinguishes them from the nearby voluminous (1000 km3), 17-22 Ma, calc-alkaline to shoshonitic volcanic centres of Lesbos and Karaburum. The minor volcanism on Chios occurred near the site of earlier voluminous arc volcanism. The rapid decrease in the rate of subduction in the mid-Miocene reduced both the production of slab-derived volatiles and silicic melts, as well as the volume of mantle wedge from which arc-type magma was extracted. At the same time, extension resulted in decompression of the lithosphere and the generation of small-volume partial melts. Volcanic products are not found near the major extensional centres: rather, they are associated with minor basin subsidence, which provided brittle pathways for magma flow. © 1994 The Geological Society.	en
heal.journalName	Geological Society Special Publication	en
dc.identifier.doi	10.1144/GSL.SP.1994.081.01.12	en
dc.identifier.volume	81	en
dc.identifier.issue	1	en
dc.identifier.spage	213	en
dc.identifier.epage	231	en