Znaczenie deformacji porozdzielanej w analizie strukturalnej

Zbigniew Cymerman



The paper presents the concept of deformation partitioning and its significance in structural analysis of metamorphic areas. Influence of deformation partitioning on development of microstructures is described, particularly of porphyroblasts. Processes of reactivation of older foliation by deformation partitioning are also presented. A model of deformation partitioning can also explain the evolution of macrostructures, particularly of fold and thrust zones.
Afterwards regional examples of the described phenomenon are presented from southwestern Poland. The Sowie Mts unit is the first one in the Sudeten variscides, the mechanisms of deformation partitioning of which have been recognized (11). Partitioning of deformations in this unit are considerably due to amphibolite macrolenses. Zones of ductile shearing were connected in the Sowie Mts unit with all five deformation phases described there.
The largest amphibolite body in southwestern Poland forms a macrospindle of Niedźwiedź and is encircled by vast shearing zones. Considerable contrast of ductility between amphibolites and surrounding gneisses and crystalline shales resulted in partitioning of deformations on a regional scale. Such regional zones of ductile shearing continue further southwards to the Nyznerov zone where partitioned fragments of ophiolites occur.
Eastern boundary of the Bohemian Massif is marked by the Moravo-Silesian shearing zone which continues in Poland in a regional shearing zone Nysa-Brzeg. This zone can separate the Sudeten terrane from the Silesian one.
Partitioned deformation must be taken into account in all structural analyses. It deals with microstructures but with macrostructures as well.