High-pressure/low-temperature metamorphism of basalts in Lavrion (Greece): Implications for the preservation of peak metamorphic assemblages in blueschists and greenschists

Baziotis, I; Proyer, A; Mposkos, E

dc.contributor.author	Baziotis, I	en
dc.contributor.author	Proyer, A	en
dc.contributor.author	Mposkos, E	en
dc.date.accessioned	2014-03-01T01:30:51Z
dc.date.available	2014-03-01T01:30:51Z
dc.date.issued	2009	en
dc.identifier.issn	0935-1221	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19651
dc.subject	Blueschist	en
dc.subject	Fluid availability	en
dc.subject	Greenschist	en
dc.subject	Lavrion area	en
dc.subject	Preservation	en
dc.subject.classification	Mineralogy	en
dc.subject.other	basalt	en
dc.subject.other	blueschist	en
dc.subject.other	dehydration	en
dc.subject.other	geothermal gradient	en
dc.subject.other	geothermometry	en
dc.subject.other	greenschist	en
dc.subject.other	high pressure	en
dc.subject.other	low temperature	en
dc.subject.other	metamorphism	en
dc.subject.other	P-T conditions	en
dc.subject.other	prograde metamorphism	en
dc.subject.other	retrograde metamorphism	en
dc.subject.other	Attica	en
dc.subject.other	Greece	en
dc.subject.other	Lavrion	en
dc.title	High-pressure/low-temperature metamorphism of basalts in Lavrion (Greece): Implications for the preservation of peak metamorphic assemblages in blueschists and greenschists	en
heal.type	journalArticle	en
heal.identifier.primary	10.1127/0935-1221/2008/0020-1853	en
heal.identifier.secondary	http://dx.doi.org/10.1127/0935-1221/2008/0020-1853	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	The Upper Tectonic Unit of the Lavrion area is part of the Attic-Cycladic blueschist belt and was affected by high-pressure, low-temperature metamorphism. Blueschists and greenschists occur in the same outcrop and are believed to have experienced the same pressure-temperature (P-T) history which has been quantified using geothermobarometry and pseudosections for specific bulk-rock compositions. Calculated P-T conditions indicate minimum pressure of ~ 0.9 GPa and temperature of ~ 370 °C for the peak of metamorphism. The prograde and retrograde paths followed a very similar low geothermal gradient (1012 °C/km) with cooling during decompression. Pseudosections show that both blueschists and greerischists can exist stably at the metamorphic peak, the dominant amphibole being a function of bulk composition: the blueschists, on average, have lower Mg# than the greenschists, which results in a larger P-T stability field of blue amphibole. A pseudosection analysis of the dehydration behaviour indicates that blueschists and some greenschists can preserve their peak assemblages (no dehydration along the retrograde path), whereas greenschist assemblages, in general, are rather prone to undergo dehydration and hence re-equilibration to lower P-T conditions during exhumation. © 2008 E. Schweizerbart'sche Verlagsbuchhandlung, D-70176 Stuttgart.	en
heal.publisher	E SCHWEIZERBARTSCHE VERLAGS	en
heal.journalName	European Journal of Mineralogy	en
dc.identifier.doi	10.1127/0935-1221/2008/0020-1853	en
dc.identifier.isi	ISI:000263454400015	en
dc.identifier.volume	21	en
dc.identifier.issue	1	en
dc.identifier.spage	133	en
dc.identifier.epage	148	en