2024-03-29T06:52:46Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/190772010-11-11T23:00:00Zcom_10261_91com_10261_8col_10261_344
D, O and C isotopes in podiform chromitites as fluid tracers for hydrothermal alteration processes of the Mayarí — Baracoa Ophiolitic Belt, eastern Cuba.
Proenza, Joaquín A.
Alfonso, P.
Melgarejo, J. C.
Gervilla, Fernando
Tritlla, J.
Fallick, Anthony Edward
Cuba
Fluids
Serpentinization
Stable isotopes
Ophiolites
6 pages, 2 figures.
The Mayarí — Baracoa Ophiolitic Belt (MBOB, eastern Cuba) is composed of two large, chromite-rich massifs: Mayarí —Cristaland Moa-Baracoa. The chromitites and hosting dunites were firstly affected by a regional serpentinization event, a subsequent episode of hydrothennal alteration (chloritization mainly) and, finally, these already altered bodies were crosscut by thin calcite-dominated veins. Analysed serpentines from serpentinized chromitites and dunites present very similar isotopic compositions (δ18O=+4.7 to +6.3 and δD= −67 to −60 , suggesting that the serpentinization process took place at moderate temperatures, in an oceanic environment. Serpentine formation by interaction with ocean water is also supported by the isotopic composition of chlorite and calcite. These results suggest that the serpentinization, chloritization and fracture filling processes of the Mayarí — Baracoa Ophiolite Belt took place in a subocean floor scenario and, thus, that the Mayarí — Baracoa serpentines represent a good example of serpentine formed during interaction with seawater. The oceanic origin of the serpentines from serpentinized chromitites and dunites from the MBOB indicate that the serpentinization of the mantle sequence occurred pre-thrusting (pre-emplacement in age).
This research was partially supported by a
posdoctoral grant of Spanish Ministerio de Educaci6n y Cultura to EA. These results are contributions to the Spanish DGES project, BTE2001-3308, an AECI grant (Programa de Cooperaci6n Cientifica con
Iberoam&ica 2000). SUERC is funded by NERC
and a consortium of Scottish Universities. We thank R.A.J. Swennen and an anonymous referee for their constructive comments that helped to improve the manuscript.
Peer reviewed
2009-11-27T08:24:21Z
2009-11-27T08:24:21Z
2003-05
artículo
http://purl.org/coar/resource_type/c_6501
Journal of Geochemical Exploration 78-79: 117-122 (2003)
http://hdl.handle.net/10261/19077
10.1016/S0375-6742(03)00021-9
en
http://dx.doi.org/10.1016/S0375-6742(03)00021-9
none
10752 bytes
application/octet-stream
Elsevier