The origin of the Popiel peridotite (Western Sudetes, SW Poland)

Autor(en)
Anna Kukula, Jacek Puziewicz, Theodoros Ntaflos
Abstrakt

A small (280 × 140 m) outcrop of peridotite occurs on Popiel Hill (Sudetes, SW Poland) within the low-grade metabasic rocks of the Rudawy Janowickie Complex, which form the eastern and northeastern cover of the Variscan Karkonosze granite. The peridotite is situated on the Intra-Sudetic Fault, one of the major Variscan dislocations in the region. The rock consists of strongly tectonised olivine (Fo84-88) and orthopyroxene (Mg# 0.84-0.88) aggregates, overgrown by tremolite-magnesiohornblende, locally forming large crystals, embedded in serpentine. Spinel and magnetite are subordinate; ilmenite, Fe-sulfide, and apatite are accessories. The bulk-rock chemical composition suggests a lherzolitic composition and the occurrence of primary clinopyroxene, now completely replaced by tremolite and magnesiohornblende. Rare Earth Element patterns are flat, slightly enriched relatively to primitive mantle, as is typical of island arc tholeiites. Olivine, orthopyroxene, and spinel were the first to crystallize, and they represent relics of a primary igneous assemblage. They were followed by tremolite and serpentine, formed during uplift and related metamorphism. The last mineral to crystallise was magnesio-hornblende, which originated due to contact metamorphism by the Karkonosze granite magma. The Popiel peridotite probably represents a small slice of lherzolitic cumulate, which originated in a tholeiitic magma chamber at the roots of a supra-subduction volcanic arc.

Organisation(en)
Department für Lithosphärenforschung
Externe Organisation(en)
Uniwersytet Wrocławski
Journal
Geological Quarterly
Band
59
Seiten
239-247
Anzahl der Seiten
9
ISSN
1641-7291
DOI
https://doi.org/10.7306/gq.1214
Publikationsdatum
2015
Peer-reviewed
Ja
ÖFOS 2012
105120 Petrologie
Schlagwörter
ASJC Scopus Sachgebiete
Geology
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/the-origin-of-the-popiel-peridotite-western-sudetes-sw-poland(a031e8c2-5d0e-4c06-9738-1f79cc541263).html