Geochemical processes and petrogenetic evolution of rodingite dykes in the ophiolite complex of Othrys (Central Greece)

Tsikouras, B; Karipi, S; Rigopoulos, I; Perraki, M; Pomonis, P; Hatzipanagiotou, K

dc.contributor.author	Tsikouras, B	en
dc.contributor.author	Karipi, S	en
dc.contributor.author	Rigopoulos, I	en
dc.contributor.author	Perraki, M	en
dc.contributor.author	Pomonis, P	en
dc.contributor.author	Hatzipanagiotou, K	en
dc.date.accessioned	2014-03-01T01:30:48Z
dc.date.available	2014-03-01T01:30:48Z
dc.date.issued	2009	en
dc.identifier.issn	0024-4937	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19633
dc.subject	Greece	en
dc.subject	Isocon	en
dc.subject	Othrys ophiolite	en
dc.subject	REE	en
dc.subject	Rodingite	en
dc.subject.classification	Geochemistry & Geophysics	en
dc.subject.classification	Mineralogy	en
dc.subject.other	diabase	en
dc.subject.other	dike	en
dc.subject.other	diopside	en
dc.subject.other	garnet	en
dc.subject.other	igneous geochemistry	en
dc.subject.other	mobilization	en
dc.subject.other	ophiolite	en
dc.subject.other	peridotite	en
dc.subject.other	petrogenesis	en
dc.subject.other	protolith	en
dc.subject.other	rare earth element	en
dc.subject.other	rodingite	en
dc.subject.other	serpentinization	en
dc.subject.other	Eurasia	en
dc.subject.other	Europe	en
dc.subject.other	Greece	en
dc.subject.other	Southern Europe	en
dc.title	Geochemical processes and petrogenetic evolution of rodingite dykes in the ophiolite complex of Othrys (Central Greece)	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.lithos.2009.06.013	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.lithos.2009.06.013	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	Rodingite dykes occur in serpentinised harzburgites in the Othrys ophiolite. Hydrogrossular and diopside along with chlorite appeared first and mark the initiation of rodingitisation of the dolerite protolith. Subsequently calcite formed after diopside and consequently reacted with chlorite to enrich the rodingites in diopside and garnet. Apatite also forms at the late stages of alteration. Several geochemical exchanges were triggered by variably alkaline and continuously evolving fluids passing through the serpentinising peridotites. A possible T-X-CO2 path along with a reaction series are proposed for the development of the rodingitic assemblages that entail a fluid phase. Leaching of the peridotite was triggered by fluids very rich in CO2 and carbonate complexes are thought to be responsible for mobilization of Cr and Ni. Under such conditions, REE also were mobile and the presence of CO32- and PO43- ions that complexed them further assisted their transportation. Zr mobilised at increased pH conditions with the aid of the OH- and PO43- during the late stage of alteration, and due to the incorporation of more saline fluids. After formation of calcite and apatite in the two metasomatic stages, respectively, the REE complexes were destabilised due to reduced activity of CO32- and PO43- and free REEs were able to precipitate onto garnet. Cr and Ni hydroxides were precipitated after formation of calcite in the rodingite. The saline fluids were also reducing, hence Eu remained in its divalent state and was highly absorbed on garnet surfaces. The rodingitisation at Othrys ophiolite occurred in a subduction regime as it is implicated by the very rich in CO2 fluid phase which is readily explained by involvement of subducted carbonate sediments and is favoured by the development of structural zones that acted as conduits to the metasomatising fluid phase. (C) 2009 Elsevier B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Lithos	en
dc.identifier.doi	10.1016/j.lithos.2009.06.013	en
dc.identifier.isi	ISI:000272787200013	en
dc.identifier.volume	113	en
dc.identifier.issue	3-4	en
dc.identifier.spage	540	en
dc.identifier.epage	554	en