From subduction channel to orogenic wedge: Exhumation recorded by orthogneiss microstructures in Erzgebirge, Bohemian Massif

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F21%3A10435416" target="_blank" >RIV/00216208:11310/21:10435416 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=q8kHyCtENv" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=q8kHyCtENv</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.tecto.2021.229096" target="_blank" >10.1016/j.tecto.2021.229096</a>

Jazyk výsledku

angličtina

Název v původním jazyce

From subduction channel to orogenic wedge: Exhumation recorded by orthogneiss microstructures in Erzgebirge, Bohemian Massif

Popis výsledku v původním jazyce

The Erzgebirge dome, exposing Proterozoic - Early Palaeozoic metagranitoids and metasedimentary rocks of the Saxothuringian domain in the Bohemian Massif, is formed by a tectonic stack of several UHP-HP and HT units exhumed during Variscan continental subduction-collision process. A systematic study of orthogneiss deformation microstructures carried out on a regional scale has been done to evaluate the extent and relative structural position of these units in the subduction complex. Five different microstructural types have been distinguished, revealing two overprinting sequences with 1) coarse grained microstructures in the parautochthonous Katerina-Reitzenhain unit and 2) finer grained microstructures in the allochthonous HP-HT Gneiss Eclogite Unit. P-T conditions of the individual overprinting microstructures calculated by conventional thermobarometry suggest continuous deformation during exhumation along two contrasting P-T paths. The warmer one in the parautochthonous unit showed exhumation from similar to 13.5 kbar and similar to 820 degrees C to similar to 3 kbar and similar to 500 degrees C while the colder one in the allochthonous unit showed exhumation from similar to 16 kbar and similar to 740 degrees C to similar to 3 kbar and similar to 400 degrees C. The overprinting microstructures are associated with vertical shortening interpreted as ductile thinning. This deformation started at depths of similar to 10 kbar and led to a temporal elevation of the crustal heat flow affecting the exhumation P-T paths of the structurally deeper units. We propose a model of continuous underplating of the former accretionary wedge by deeply subducted and exhumed continental material building up the orogenic wedge. Progressive heating of the orogenic wedge is explained by heat advection related to fast exhumation of the UHP/HP-HT units from the subduction channel followed by ductile thinning.

Název v anglickém jazyce

From subduction channel to orogenic wedge: Exhumation recorded by orthogneiss microstructures in Erzgebirge, Bohemian Massif

Popis výsledku anglicky

The Erzgebirge dome, exposing Proterozoic - Early Palaeozoic metagranitoids and metasedimentary rocks of the Saxothuringian domain in the Bohemian Massif, is formed by a tectonic stack of several UHP-HP and HT units exhumed during Variscan continental subduction-collision process. A systematic study of orthogneiss deformation microstructures carried out on a regional scale has been done to evaluate the extent and relative structural position of these units in the subduction complex. Five different microstructural types have been distinguished, revealing two overprinting sequences with 1) coarse grained microstructures in the parautochthonous Katerina-Reitzenhain unit and 2) finer grained microstructures in the allochthonous HP-HT Gneiss Eclogite Unit. P-T conditions of the individual overprinting microstructures calculated by conventional thermobarometry suggest continuous deformation during exhumation along two contrasting P-T paths. The warmer one in the parautochthonous unit showed exhumation from similar to 13.5 kbar and similar to 820 degrees C to similar to 3 kbar and similar to 500 degrees C while the colder one in the allochthonous unit showed exhumation from similar to 16 kbar and similar to 740 degrees C to similar to 3 kbar and similar to 400 degrees C. The overprinting microstructures are associated with vertical shortening interpreted as ductile thinning. This deformation started at depths of similar to 10 kbar and led to a temporal elevation of the crustal heat flow affecting the exhumation P-T paths of the structurally deeper units. We propose a model of continuous underplating of the former accretionary wedge by deeply subducted and exhumed continental material building up the orogenic wedge. Progressive heating of the orogenic wedge is explained by heat advection related to fast exhumation of the UHP/HP-HT units from the subduction channel followed by ductile thinning.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA17-22207S" target="_blank" >GA17-22207S: Role zděděné architektury kontinentálního okraje na ranně Variskou konvergenci</a><br>

Návaznosti

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

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

Tectonophysics

ISSN

0040-1951

e-ISSN

—

Svazek periodika

820

Číslo periodika v rámci svazku

neuvedeno

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

19

Strana od-do

229096

Kód UT WoS článku

000710178600001

EID výsledku v databázi Scopus

2-s2.0-85117688002