We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Geochemistry of the Osnitsk-Mikashevichy volcanoplutonic complex of the Ukrainian shield.
- Authors
Shumlyanskyy, L.
- Abstract
This paper addresses the geochemistry of intrusive (Osinitsk complex) and volcanic (Klesov Group) rocks of the Osnitsk-Mikashevichy volcanoplutonic belt (OMVPB) of the Ukrainian shield, which is an active continental margin existing approximately 1980-2000 Ma ago. The Osnitsk complex comprises a wide range of rocks, from ultrabasics to granitoids, and the Klesov Group is dominated by extrusive rocks of basaltic and rhyolitic compositions metamorphosed under epidote-amphibolite facies conditions. The Sr-Nd-Hf isotopic systematics (ɛSr from −4 to +10, ɛNd from −0.6 to +2.3, and ɛHf1990 from 0.1 to 1.4) indicates a juvenile source for the OMVPB rocks. Geochemical data suggest independent origin of the rocks of gabbroid (SiO < 60 wt %) and granitoid (SiO > 60 wt %) series. The gabbroids are subdivided into pre- and post-granite groups on the basis of the higher contents of incompatible trace elements and lower contents of compatible elements in the post-granite rocks. The geochemical characteristics of the two groups of basic rocks indicate their formation in a convergent tectonic setting. The origin of the granitoid melts is attributed to the low-degree (eutectoid) melting of basic rocks at relatively low temperatures.
- Subjects
VOLCANIC ash, tuff, etc.; GRANITE; MAFIC rocks; BASALT; FLOOD basalts; THOLEIITE
- Publication
Geochemistry International, 2014, Vol 52, Issue 11, p912
- ISSN
0016-7029
- Publication type
Article
- DOI
10.1134/S0016702914110081