Search citation statements
Paper Sections
Citation Types
Year Published
Publication Types
Relationship
Authors
Journals
The Eastern Alps were affected by a profound post‐collisional tectonic reorganisation in Neogene time, featuring indentation by the Adriatic upper plate, rapid uplift and filling of the eastern Molasse Basin, exhumation and eastward orogen‐parallel transport of Paleogene metamorphic units in the orogenic core, and a shift from northward thrust propagation in the European plate to southward propagation in the Adriatic plate. We test the idea that these events were triggered by slab detachment by reconstructing the indentation process. This involves sequentially restoring N‐S and E‐W cross‐sections of the orogenic wedge and correcting for out‐of‐section orogen‐parallel transport with a map‐view reconstruction. We propose two phases of indentation: Initially (23 and 14 Ma), the whole Adriatic crust acted as an indenter. Its northward motion was accommodated by upright folding and orogen‐parallel extensional exhumation in the Tauern Window. This phase was followed (14 Ma to Present) by continued orogen‐parallel transport of the orogenic wedge into the Pannonian Basin and deformation of the leading edge of the Adriatic indenter, forming the Southern Alps fold‐thrust belt. The lower crust of the Southern Alps indented the base of the Venediger Nappes in the Tauern Window, forming a high‐velocity (6.8–7.25 km/s) ridge in map view at 30–45 km depth. By correlating the post‐23 Ma orogenic evolution with presently imaged European slab segments in P‐wave teleseismic tomography, we discern two possible Neogene slab removal events: One from 23 to 19 Ma triggering tectonic reorganisation of the Eastern Alps and its foreland basin, and potentially a second event after 14 Ma.
The Eastern Alps were affected by a profound post‐collisional tectonic reorganisation in Neogene time, featuring indentation by the Adriatic upper plate, rapid uplift and filling of the eastern Molasse Basin, exhumation and eastward orogen‐parallel transport of Paleogene metamorphic units in the orogenic core, and a shift from northward thrust propagation in the European plate to southward propagation in the Adriatic plate. We test the idea that these events were triggered by slab detachment by reconstructing the indentation process. This involves sequentially restoring N‐S and E‐W cross‐sections of the orogenic wedge and correcting for out‐of‐section orogen‐parallel transport with a map‐view reconstruction. We propose two phases of indentation: Initially (23 and 14 Ma), the whole Adriatic crust acted as an indenter. Its northward motion was accommodated by upright folding and orogen‐parallel extensional exhumation in the Tauern Window. This phase was followed (14 Ma to Present) by continued orogen‐parallel transport of the orogenic wedge into the Pannonian Basin and deformation of the leading edge of the Adriatic indenter, forming the Southern Alps fold‐thrust belt. The lower crust of the Southern Alps indented the base of the Venediger Nappes in the Tauern Window, forming a high‐velocity (6.8–7.25 km/s) ridge in map view at 30–45 km depth. By correlating the post‐23 Ma orogenic evolution with presently imaged European slab segments in P‐wave teleseismic tomography, we discern two possible Neogene slab removal events: One from 23 to 19 Ma triggering tectonic reorganisation of the Eastern Alps and its foreland basin, and potentially a second event after 14 Ma.
Low-relief surfaces at high elevations are peculiar features of the Eastern Alps that are best explained as relicts of morphological base levels that escaped erosive decay during uplift. To expand our knowledge of such surfaces in the Eastern Alps, the Fischbach Alps at the eastern end of the range are investigated. There, a large number of these elevated low-relief surfaces have been known for some time, but modern mapping is absent and their genesis is not well understood. A combined approach of field mapping, morphometric analysis of a digital elevation model and downstream projection of geomorphic equilibrium sections in river profiles was employed to: (i) create a geomorphological map of the region and (ii) to extract quantitative data from river profiles to infer the amount of uplift and incision. Six discrete levels of low-relief surfaces and relict landscapes are recognized at elevations between ~500 m and ~1600 m. Some of the lower levels are interpreted to relate to the well-known Trahutten, Landscha and Stadelberg levels, known from other parts of Styria, respectively. Mapped low-relief surface levels follow the northward directed topographic gradient in the mountainous region of the Fischbach Alps. The formation of elevated low-relief surfaces is consistent with a Piedmonttreppen model, where successive phases of tectonic uplift and tectonic quiescence led to a succession of incised landscapes and low-relief surfaces. However, the entire region south of the Murztal was also then tilted towards the Styrian Basin by about ~1–2°. Swath profile analysis for the Raab and Weizbach Klamm suggests a minimum of ~400–450 m incision since the formation of the so called Hubenhalt level. This implies that the geomorphic response to tectonic uplift after the formation of the higher Wolscheneck and Koralm relict landscapes led to an estimated incision of up to 1000 m (868±101 m), relative to the base level of today’s Styrian Basin at ~380 m. By comparing published age data to the presented mapping results, the onset for much of the uplift at the eastern end of the Alps is suggested to lie between ~4–7 Ma, before the formation of the Hubenhalt and Trahutten levels. Because the mapped levels correlate well with those in many other regions at similar elevations, a growing body of work now suggests that the underlying uplift event has a large wavelength.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.