Miocene high elevation and high relief in the Central Alps

Krsnik, E., Methner, K., Campani, M., Botsyun, S., Mutz, S. G. , Ehlers, T. A. , Kempf, O., Fiebig, J., Schlunegger, F. and Mulch, A. (2021) Miocene high elevation and high relief in the Central Alps. Solid Earth, 12(11), pp. 2615-2631. (doi: 10.5194/se-2021-59)

Abstract

Reconstructing Oligocene–Miocene paleoelevation contributes to our understanding of the evolutionary history of the European Alps and sheds light on geodynamic and Earth surface processes involved in the development of Alpine topography. Despite being one of the most intensively explored mountain ranges worldwide, constraints on the elevation history of the European Alps remain scarce. Here we present stable and clumped isotope measurements to provide a new paleoelevation estimate for the mid-Miocene (∼14.5 Ma) European Central Alps. We apply stable isotope δ–δ paleoaltimetry to near-sea-level pedogenic carbonate oxygen isotope (δ18O) records from the Northern Alpine Foreland Basin (Swiss Molasse Basin) and high-Alpine phyllosilicate hydrogen isotope (δD) records from the Simplon Fault Zone (Swiss Alps). We further explore Miocene paleoclimate and paleoenvironmental conditions in the Swiss Molasse Basin through carbonate stable (δ18O, δ13C) and clumped (Δ47) isotope data from three foreland basin sections in different alluvial megafan settings (proximal, mid-fan, and distal). Combined pedogenic carbonate δ18O values and Δ47 temperatures (30±5 ∘C) yield a near-sea-level precipitation δ18Ow value of -5.8±1.2‰ and, in conjunction with the high-Alpine phyllosilicate δD value of  -14.6±0.3‰, suggest that the region surrounding the Simplon Fault Zone attained surface elevations of >4000 m no later than the mid-Miocene. Our near-sea-level δ18Ow estimate is supported by paleoclimate (iGCM ECHAM5-wiso) modeled δ18O values, which vary between −4.2 ‰ and −7.6 ‰ for the Northern Alpine Foreland Basin.

• Item Type: Articles
• Additional Information: This research has been supported by the Deutsche Forschungsgemeinschaft (grant nos. DFG ME 4955/1-1, DFG MU 2845/6-1, DFG EH 329/19-1, DFG MU 4188/1-1, and DFG FI 948/4-1).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Ehlers, Professor Todd A. and Mutz, Dr Rer Nat Sebastian
• Authors: Krsnik, E., Methner, K., Campani, M., Botsyun, S., Mutz, S. G., Ehlers, T. A., Kempf, O., Fiebig, J., Schlunegger, F., and Mulch, A.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Solid Earth
• Publisher: Copernicus Publications for the European Geosciences Union
• ISSN: 1869-9510
• ISSN (Online): 1869-9529
• Copyright Holders: Copyright: © The Author(s) 2021
• First Published: First published in Solid Earth 12(11): 2615–2631
• Publisher Policy: Reproduced under a Creative Commons licence