P-T evolution of Precambrian eclogite in the Sveconorwegian orogen, SW Sweden

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F17%3A00000298" target="_blank" >RIV/00025798:_____/17:00000298 - isvavai.cz</a>

Result on the web

<a href="http://onlinelibrary.wiley.com/doi/10.1111/jmg.12242/full" target="_blank" >http://onlinelibrary.wiley.com/doi/10.1111/jmg.12242/full</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/jmg.12242" target="_blank" >10.1111/jmg.12242</a>

Result language

angličtina

Original language name

P-T evolution of Precambrian eclogite in the Sveconorwegian orogen, SW Sweden

Original language description

Conditions of the prograde, peak-pressure and part of the decompressional P–T path of two Precambrian eclogites in the eastern Sveconorwegian orogen have been determined using the pseudosection approach. Cores of garnet from a Fe-Ti-rich eclogite sample record a first prograde and syn-deformational stage along a Barrovian geothermal gradient from ~670 °C and 7 kbar to 710 °C and 8.5 kbar. Garnet rims grew during further burial to 16.5-19 kbar at ~850-900 °C, along a steep dP/dT gradient. The pseudosection model of a kyanite-bearing eclogite sample of more magnesian bulk composition confirms the peak conditions. Matrix reequilibration associated with subsequent near-isothermal decompression and partial exhumation produced plagioclase-bearing symplectites replacing kyanite and clinopyroxene and is estimated at 850-870 °C and 10-11 kbar. The validity of the pseudosections is discussed in detail. It is shown that in pseudosection modelling the fractionation of FeO in accessory sulphides may cause a significant shift of field boundaries (here displaced by up to 1.5 kbar and 70 °C) and must not be neglected. Fast burial, exhumation and subsequent cooling are supported by the steepness of both the prograde and the decompressional P–T paths as well as the preservation of garnet growth zoning and the symplectitic reaction textures. These features are compatible with deep tectonic burial of the eclogite-bearing continental crust as part of the underthrusting plate (Eastern Segment, continent Baltica) in a collisional setting that led to an effectively doubled crustal thickness and subsequent exhumation of the eclogites through tectonic extrusion. Our results are in accordance with regional structural and petrologic relationships, which demonstrate foreland-vergent partial exhumation of the eclogite-bearing nappe along a basal thrust zone and support a major collisional stage at c. 1 Ga. We argue that the similarities between Sveconorwegian and Himalayan eclogite occurrences emphasize the modern style of Grenvillian-aged tectonics.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10505 - Geology

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

Confidentiality

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

Name of the periodical

Journal of Metamorphic Geology

ISSN

0263-4929

e-ISSN

—

Volume of the periodical

35

Issue of the periodical within the volume

5

Country of publishing house

GB - UNITED KINGDOM

Number of pages

23

Pages from-to

493-515

UT code for WoS article

000402647600002

EID of the result in the Scopus database

2-s2.0-85013077971