Subduction in the remnant oceanic basin

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This chapter serves as an overview of facts on the Carpathian-Pannonian Tertiary development. It discusses about 35 geophysical-geological data layers of the database presented in the entire chapter, correlates them briefly, and notes the main results of such a multidisciplinary synthesis. This synthesis indicates that the remnant Carpathian Flysch Basin (rCFB) was affected by subduction since the earlyMiocene. Areas to the west and east of the rCFB were undergoing continent-continent collisions at the same time. From the late Oligocene to middle Miocene, crustal wedges moving laterally from these collisions became parts of the Carpathian-Pannonian slab overriding the rCFB. This basin underwent passive subduction characterized by passive sinking of the oceanic slab under its body forces. Subduction setting was characterized by a steep dip of the subducting slab, strong hinterland extension, extensive areal magmatismin the hinterland, and asthenospheric upwelling in the hinterland. The oceanic plate underlying the rCFB subducted southwestward and westward. The subduction rollback of the subducting slab under the advancing Carpathian orogen, the oblique closure of the rCFB, and the progressive change of subduction to collision from west to east along the Carpathian arc drove a scissorlike break-off of the subducting oceanic slab along the Carpathians. The break-off was driven by the weight of the subducting oceanic slab and the buoyancy of the attached continental slab. The break-off ran eastward along the whole Carpathian arc, from the early Miocene to its present position in the bend between the Eastern and Southern Carpathians.

Subduction, oceanic basin

Nemcok, M., L. Pospisil, I. Hrušecký and T. Zsiros

2007

9. 1. 2007

AAPG

978-0-89181-365-1

The Carpathians and their Foreland: Geology and Hydrocarbon Resources

AAPG Memoirs

84

757

785

29