Timing of the Onset of Collision in the Central and Northern Urals

摘要

Orogenic systems are formed due to accretion and/or collision. Accretion is mainly accompanied by structural changes, which also involve the formation of various sedimentary, magmatic, and metamorphic associations. The hierarchy of collision events and related rock associations in orogenic systems is rather complicated. Associations of interblock, interzonal, and intersegment collision [2] are distinguished for the Ural foldbelt (UFB). The general structure of this major compression orogen is determined by the Late Paleozoic collision [1 and others]. The first associations represented by metamorphic schists, blastomylonites, and blastocataclasites are accompanied by small diorite, granodiorite, and syenite massifs and dikes. The second associations include volcanic-intrusive areas and multiphase (acid and basic) massifs. Hypercollision processes in the UFB are reflected in sheet structures, complete folding, large granitoid massifs, and the Ural Foredeep filled with the Early Permian molasse [1,3, and others].