Reply to comments by A. Krohe and A.P. Willner on “Structural evolution of the central part of the Krušné Hory (Erzgebirge) Mountains in the Czech Republic—evidence for changing stress regime during Variscan compression”

U-Pb and Pb-Pb zircon ages for metamorphic rocks in the Kaoko Belt of Northwestern Namibia: A Palaeo- to Mesoproterozoic basement reworked during the Pan-African orogeny

The Kaoko Belt belongs to the Neoproterozoic mobile belt system of western Gondwana, whose geodynamic evolution is assumed to have resulted from collision between the Congo Craton (present Africa) and the Rio de la Plata Craton (present South America). Several magmatic intrusion periods can be distinguished in the coastal area of this belt, based on conventional U-Pb, SHRIMP and Pb-Pb evaporation analyses on zircons. The prevailing igneous rock types are of granitic to tonalitic composition. A Palaeoproterozoic terrain with U-Pb magmatic emplacement ages between ~2.03 and 1.96 Ga may be correlated with the Eburnian event (~1.8 to 2.0 Ga), which is widespread in Africa. Additionally, two dis…

Oblique collision and evolution of large-scale transcurrent shear zones in the Kaoko belt, NW Namibia

Abstract Early structures in the central part of the Kaoko orogenic belt of NW Namibia suggest that the initial stage of collision was governed by underthrusting of the medium-grade Central Kaoko zone below the high-grade Western Kaoko zone, resulting in the development of an inverted metamorphic gradient. In the Western zone, early structures were overprinted by a second phase of deformation, which is associated with localization of the transcurrent Puros shear zone along the contact between the Western and Central zones. During this second phase, extensive partial melting and intrusion of ∼550 Ma granitic bodies occurred in the high-grade Western zone. In the Central zone, the second phas…

Geometric aspects of synkinematic granite intrusion into a ductile shear zone — an example from the Yunmengshan core complex, northern China

The Cretaceous Yungmengshan core complex in northern China contains a large syntectonic granodiorite batholith that intrudes a slightly older diorite intrusion. A major gently dipping ductile decollement shear zone is developed along the contact of the diorite and granodiorite. The shear zone is invaded by a large volume of granitic and pegmatite veins associated with the main granodiorite batholith during activity of the shear zone under high-grade metamorphic conditions. Progressively older veins are more strongly deformed into tight cylindrical fold structures rotated into parallelism with the lineation and foliation in the shear zone. Parallelism of veins to the foliation is partly due …