Petrology and geochemistry of a peridotite body in Central-Carpathian Paleogene sediments (Sedlice, eastern Slovakia)

Author(s)
Matus Koppa, Friedrich Koller, Marian Putis
Abstract

We studied representative samples from a peridotite body situated NE of Sedlice village within the Central- Carpathian Paleogene sediments in the Central Western Carpathians. The relationship of the peridotite to the surrounding Paleogene sediments is not clear. The fractures of the brecciated peridotite margin are healed with secondary magnesite and calcite. On the basis of the presented bulk-rock and electron microprobe data, the wt. % amounts of mineral phases were calculated. Most of calculated "modal" compositions of this peridotite corresponds to harzburgites composed of olivine (∼70-80 wt. %), orthopyroxene (∼17-24 wt. %), clinopyroxene ( < 5 wt. %) and minor spinel ( < 1 wt. %). Harzburgites could originate from lherzolitic protoliths due to a higher degree of partial melting. Rare lherzolites contain porphyroclastic 1-2 mm across orthopyroxene (up to 25 wt. %), clinopyroxene (∼ 5-8 wt. %) and minor spinel ( < 0.75 wt. %). On the other hand, rare, olivine-rich dunites with scarce orthopyroxene porphyroclasts are associated with harzburgites. Metamorphic mineral assemblage of low-Al clinopyroxene (3), tremolite, chrysotile, andradite, Cr-spinel to chromite and magnetite, and an increase of fayalite component in part of olivine, indicate low-temperature metamorphic overprint. The Primitive Mantle normalized whole-rock REE patterns suggest a depleted mantle rock-suite. An increase in LREE and a positive Eu anomaly may be consequence of interactive metamorphic fluids during serpentinization. Similar rocks have been reported from the Meliatic Bôrka Nappe overlying the Central Western Carpathians orogenic wedge since the Late Cretaceous, and they could be a potential source of these peridotite blocks in the Paleogene sediments.

Organisation(s)
Department of Lithospheric Research
External organisation(s)
Comenius University Bratislava
Journal
Geologica Carpathica
Volume
65
Pages
387-399
No. of pages
13
ISSN
1335-0552
DOI
https://doi.org/10.2478/geoca-2014-0022
Publication date
10-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
105105 Geochemistry, 105120 Petrology
Keywords
ASJC Scopus subject areas
Geology
Portal url
https://ucrisportal.univie.ac.at/en/publications/8d838e47-7b4e-4ed0-98bf-792896445d1a