Evolution of microstructure and texture in small-scale high-temperature shear zone in marble from Ossa Morena Zone (Iberian Variscan Belt)
Machek, Matěj (Institute of Geophysics (República Txeca))
Roxerová, Zuzana (Institute of Geophysics (República Txeca))
Kusbach, Vladimír K (Institute of Geophysics (República Txeca))
Kučeráková, Monika (Czech Technical University (República Txeca))
Vratislav, Stanislav (Czech Technical University (República Txeca))

Fecha:	2025
Resumen:	This research investigates microstructures and crystallographic preferred orientation in a high-temperature Variscan small-scale shear zone within marbles from the south-western Ossa-Morena Zone (Iberian Variscan Belt). Quantitative microstructural analysis, and crystallographic preferred orientation data obtained via neutron diffraction and electron backscatter diffraction mapping allowed to infer the deformation mechanisms and active slip systems. The primary S2 foliation fabric formed during the Variscan D2 deformation phase, is characterized by high-temperature grain boundary migration recrystallization mechanism, coupled with intracrystalline slip on the c(0001)<-12-10> system. Ductile shear zone development, marked by a coarse-grained microstructure with pronounced shape preferred orientation parallel to the shear plane, involved both high-temperature grain boundary migration recrystallization and intracrystalline dislocation creep, accommodated by f{-1012} <10-11> and r{10-14} <-2021> slip systems. These results indicate a high-temperature extensional origin for the S2 foliation and the shear zone formation during the D2 deformation event of the Ossa-Morena Zone, linked to thermal effects of from the Beja Igneous Complex plutonism and regional partial melting driven by asthenosphere upwelling (~353-335Ma).
Derechos:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre i quan aquestes es distribueixin sota la mateixa llicència que regula l'obra original i es reconegui l'autoria.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Calcite microstructure ; High-temperature shear zone ; Crystallographic preferred orientation ; Grain boundary migration recrystallization ; Deformation mechanism
Publicado en:	Geologica acta, Vol. 23 (2025) (Articles) , ISSN 1696-5728

Adreça original: https://revistes.ub.edu/index.php/GEOACTA/article/view/50257
DOI: 10.1344/GeologicaActa2025.23.24

22 p, 38.6 MB

El registro aparece en las colecciones:
Artículos > Artículos publicados > Geologica acta
Artículos > Artículos de investigación