1. Variscan dismembered metaophiolite suite fragments of Paleo-Tethys in Gemeric unit, Western Carpathians.
- Author
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RADVANEC, MARTIN, NÉMETH, ZOLTÁN, KRÁĽ, JÁN, and PRAMUKA, SILVESTER
- Subjects
PETROLOGY ,MID-ocean ridges ,GNEISS ,FACIES ,IGNEOUS intrusions ,AMPHIBOLITES ,METAMORPHISM (Geology) - Abstract
The Variscan dismembered ophiolite suite is exhumed in the northern zone of Gemeric unit of the Western Carpathians (so-called North Gemeric zone). It consists of variegated lithology of former segment of Paleozoic mid-ocean ridge of Paleo-Tethys, occurring now in three traditional principal localities of the gneiss-amphibolite complex (GAC) in the Gemeric unit (Western Carpatians) - the Dobšiná, Rudňany and Klátov localities. Additional smaller occurrences at Jaklovce, Delava and Dobšiná (Cpx metagabbro) and the Strážny vrch hill (serpentinite) were recently also added to this suite. The Paleozoic ophiolite suite in Gemeric unit is built of six polymetamorphosed principal rock types: (1) gneiss with garnet (Alm+Pl+Bt+Ms+Qtz+Act+Chl) and graphite (occurrences at Dobšiná and Rudňany), (2) plagiogranite (Kfs+Ab+Pl+Ms+Bt-Qtz+Zo+Cal;
87 Sr/86 Sr=0.7033; age 374 Ma Rudňany), (3) gneiss with amphibole porphyroclasts (Cum-Hbl/Prg-Act) and graphite (Klátov), (4) amphibolite (Pl+Hbl+Tnt+Ap+Pmp+Ilm+Act+Ep+Chl; Klátov, Rudňany, Dobšiná); (5) serpentinite (Tlc+Tr+Chl+Act+Dol+Ctl+CrSpl+Hem; Klátov, Strážny vrch hill); (6) metagabbro (Di+Aug+CrSpl+Pl+Hbl/Prg-KPrg-Act+Ep+Qtz+Tnt+Chl+MnIlm+Tnt+Ap+Zrn+Png+Ab+Hyl, Jaklovce, Delava, Dobšiná). The suite of above listed rocks underwent a multi-stadial tectono-metamorphic overprint. First - Late Devonian to Early Carboniferous low-pressure amphibolite facies metamorphism M0 (deformation stage VD0) of ocean fl oor is documented by the hornblende cooling age 362 Ma. Later metamorphic recrystallization of the pumpellyite-actinolite facies is related to compressional Variscan orogenic stage M1a (VD1a) affecting the metaophiolite suite in Late Carboniferous (around 300 Ma). During Permian metamorphism M1b (VD1b), the tectonic blocks of metaophiolite suite underwent recrystallization in the epidote-amphibolite facies to amphibolite facies by the input of heat at medium pressure. This metamorphism on the hot line was accompanied with the origin od anatectic granite of S-type and corresponding volcanism on the surface. The youngest metamorphic overpring M2 (AD2) in the greenschist facies is the result of Alpine orogenic processes. [ABSTRACT FROM AUTHOR]- Published
- 2017