Metamorphic reactions and textural changes in coronitic metagabbros from the Tepla Crystalline and Marianske Lazne complexes, Bohemian Massif

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F16%3A10331622" target="_blank" >RIV/00216208:11310/16:10331622 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.3190/jgeosci.216" target="_blank" >http://dx.doi.org/10.3190/jgeosci.216</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3190/jgeosci.216" target="_blank" >10.3190/jgeosci.216</a>

Result language

angličtina

Original language name

Metamorphic reactions and textural changes in coronitic metagabbros from the Tepla Crystalline and Marianske Lazne complexes, Bohemian Massif

Original language description

Coronitic metagabbros occur along the contact between the Mariánské Lázně and the Teplá Crystalline complexes in the NW part of the Teplá-Barrandian Unit in the Bohemian Massif. They show variable metamorphic and textural characteristics with respect to their magmatic mineral assemblage and degree of metamorphism. Magmatic mineral assemblages represented by plagioclase, orthopyroxene, clinopyroxene, amphibole, biotite, ilmenite, olivine, spinel or quartz are well preserved. Metamorphism is reflected by the formation of coronas at the contact of plagioclase with the other primary minerals. The coronas consist of amphibole, garnet and orthopyroxene. The breakdown of magmatic plagioclase is reflected by the formation of a mixture of An(40) and An(90) plagioclase associated with spinel, corundum and kyanite. The calculated P-T conditions show an increase in metamorphic grade towards the structural footwall, i. e. from the ESE (-600 +/- 50 degrees C; 10 +/- 1.5 kbar) to the WNW (-700 +/- 50 degrees C; 13.5 +/- 1.5 kbar), which corresponds to the Variscan metamorphic field gradient in this area. Since there is no gap in P-T conditions between metagabbros included in MLC and TCC and showing similar age and geochemical signature, it is concluded that both complexes were brought together before the gabbro intrusion at 500 Ma. In addition, the maximum pressure of 14 kbar estimated for the metamorphism of the gabbro occurring in the eclogite-bearing Mariánské Lázně Complex suggests that the eclogite-facies metamorphism might have been pre-Variscan. The chemistry of the studied metagabbros corresponds to subalkaline basalts with trace element signatures characteristic of E-MORB, which is consistent with an interpretation that the intrusion of these rocks was related to an intracontinental rifting of the Teplá-Barrandian Unit during Late Cambrian and was not connected to any subduction processes.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

DB - Geology and mineralogy

OECD FORD branch

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Project

<a href="/en/project/GA13-16315S" target="_blank" >GA13-16315S: Prograde metamorphism, crustal thickening and lower crustal flow: new concept of building of crustal root in Variscan orogen</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Geosciences

ISSN

1802-6222

e-ISSN

—

Volume of the periodical

61

Issue of the periodical within the volume

3

Country of publishing house

CZ - CZECH REPUBLIC

Number of pages

27

Pages from-to

193-219

UT code for WoS article

000390359400001

EID of the result in the Scopus database

2-s2.0-84991781160