EGU25-12480, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-12480
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Electron spin resonance (ESR) signals in calcite: a novel thermochronometer to constrain carbonate mountain erosion?
Melanie Kranz-Bartz1,2, Zuzanna Kabacińska3, Christoph Schmidt2, Aditi K. Dave2, Xiaoxia Wen2, and Georgina E. King2
Melanie Kranz-Bartz et al.
  • 1Ruhr University Bochum, Institute for Geology, Mineralogy, and Geophysics, Bochum, Germany (melanie.kranz@ruhr-uni-bochum.de)
  • 2University of Lausanne, Institute of Earth Surface Dynamics, Lausanne, Switzerland
  • 3Adam Mickiewicz University, Geochronology Research Unit, Institute of Geology, Faculty of Geographical and Geological Sciences, Poznan, Poland

The interaction between surface processes, climate and tectonics determines the landscape in alpine regions, with lithology playing a key role. Carbonate rocks, which cover a significant portion of Earth’s terrestrial surface, are more sensitive to environmental changes such as dissolution by meteoric waters compared to siliciclastic or crystalline rocks. This distinct sensitivity makes carbonate rocks important in geomorphological studies, particularly regarding erosion rates. However, the factors influencing erosion rates in alpine carbonate areas remain poorly understood, especially over the (sub-)Quaternary period. Existing techniques are not well-suited to measure erosion rates in carbonate minerals over timescales of 10⁶ years due to limitations in sensitivity or applicability to carbonate rocks in alpine regions. This study explores the potential of electron spin resonance (ESR) signals in calcite as a novel thermochronometer to fill the spatial and temporal gap for constraining Quaternary rock cooling and exhumation rates in carbonate mountain landscapes.

An ideal setting for this investigation has been identified in the European Alps (Rhône Valley, Switzerland), where six samples were collected along vertical (~400-1100 m a.s.l., n=3) and horizontal (~400 m a.s.l., n=3) transects. Analysis of dose response and isothermal decay data from ESR signals demonstrates sufficient stability up to 106 years, allowing us to invert low rock cooling rates (~10 °C/Myr). Our study highlights the potential of ESR thermochronometry of carbonate minerals, supported by several key findings: (i) multiple ESR signals with different thermal sensitivities can be measured in a single sample, (ii) high upper dating limits of 106-107 years, (iii) low closure temperatures (<80 °C), enabling the investigation of recent erosion processes, and (iv) the ability to constrain low exhumation rates of <1 mm/yr. By providing a reliable tool for constraining exhumation rates in carbonate mountain regions, ESR thermochronometry can significantly advance our understanding of the complex interactions between tectonics, climate, and surface processes over Quaternary timescales.

How to cite: Kranz-Bartz, M., Kabacińska, Z., Schmidt, C., Dave, A. K., Wen, X., and King, G. E.: Electron spin resonance (ESR) signals in calcite: a novel thermochronometer to constrain carbonate mountain erosion?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12480, https://doi.org/10.5194/egusphere-egu25-12480, 2025.