Changing patterns of exhumation and denudation in front of an advancing crustal indenter, Tauern Window (Eastern Alps). Issue 6 (5th June 2017)

• Record Type: Journal Article
• Authors: Favaro, S.; Handy, M. R.; Scharf, A.; Schuster, R.
• Is Part Of: Tectonics. Volume 36:Issue 6(2017)
• Page Start: 1053
• Page End: 1071
• Publication Date: 2017-06-05
• Subjects: indentation -- collision -- Alps -- denudation -- orogen‐parallel escape; Geology, Structural -- Periodicals; 551.8
• DOI: 10.1002/2016TC004448
• Languages: English
• ISSNs: 0278-7407

Abstract

Abstract: The changing shape of indenting crustal blocks during northward motion of the Adriatic microplate induced migration of Miocene doming and orogen‐parallel extension of orogenic crust in the Tauern Window. New structural and kinematic data indicate that initial shortening of the Penninic nappe pile in the Tauern Window by upright folding and strike‐slip faulting was transitional to coeval north‐south shortening and east‐west extension; the latter was accommodated by normal faulting at the eastern and western margins of the window. Retrodeforming these post‐nappe structures in map view yields a map‐view reconstruction of the orogenic crust back to 30 Ma, including the onset of pronounced indentation at ~21 Ma. This model supports the notion that indentation involved approximately equal amounts of north‐south shortening and orogen‐parallel stretching and extrusion toward the Pannonian Basin, as measured from the indenter tip to the European foreland in the north and Austroalpine units in the east. Comparison of areal denudation of the orogenic crust before and after indentation indicates that erosion associated with upright folding was the primary agent of denudation, whereas extensional unroofing and limited erosion along normal faults at the eastern and western ends of the Tauern Window accounted for only about a third of the total denudation. Key Points: Post‐nappe folding during indentation of orogenic crust in the Tauern Window was transitional to orogen‐parallel extension At the leading edge of an indenting block, initial strike‐slip faulting during early indentation was transitional to extension 60–70% of denudation was due to post‐nappe folding and erosion, the rest to coeval exhumation and erosion during normal faulting