Salt-rich versus salt-poor structural scenarios in the central Northern Calcareous Alps

Author(s)
Oscar Fernandez, Hugo Ortner, Diethard Sanders, Bernhard Grasemann, Thomas Leitner
Abstract

One of the most remarkable features of the central Northern Calcareous Alps (Eastern Alps, Austria) is the widespread presence of Upper Triassic deep-water carbonates (the Hallstatt facies) and Permo-Triassic evaporites resting on deep-water Middle Jurassic strata and their underlying Upper Triassic shallow-water carbonate platform successions. The Hallstatt facies and accompanying evaporites have been classically interpreted to originate either from a location south of the time-equivalent carbonate platforms, or to have been deposited in deeper water seaways within the broad platform domain. To date, this dispute has been addressed mostly through the analysis of Triassic and Jurassic facies distribution in map view, which, however, is subject to some degree of ambiguity and subjectivity. In this contribution we present, for the first time, sequentially restored regional cross-sections through the central Northern Calcareous Alps to understand the implications of the contrasting paleogeographic models. We present (a) an interpretation based on a highly allochthonous origin of the Triassic deep-water units and (b) an interpretation based on their relative autochthony in which we incorporate the potential influence of salt tectonics in the central NCA. The restored cross-sections provide a framework within which the alternative scenarios and their paleogeographic implications can be better understood. Through this analysis we propose that salt tectonics in the central NCA can provide a valid explanation for apparent inconsistencies in the relative autochthony scenario and thus constitutes a reasonable alternative to the currently accepted allochthony scenario. Graphical abstract: (Figure presented.).

Organisation(s)
Department of Geology
External organisation(s)
Salinen AG, Leopold-Franzens-Universität Innsbruck
Journal
International Journal of Earth Sciences
Volume
113
Pages
245-283
No. of pages
39
ISSN
1437-3254
DOI
https://doi.org/10.1007/s00531-023-02377-4
Publication date
2024
Peer reviewed
Yes
Austrian Fields of Science 2012
105124 Tectonics
Keywords
ASJC Scopus subject areas
General Earth and Planetary Sciences
Portal url
https://ucrisportal.univie.ac.at/en/publications/9d388473-2364-4a45-ae73-636349d4c1d5