EGU2020-19597
https://doi.org/10.5194/egusphere-egu2020-19597
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Evidence of recent activity in the Camorro Fault (Central Betics, Southern Spain)

Jorge P. Galve, Cristina Reyes-Carmona, Antonio Jabaloy, Patricia Ruano, José Vicente Pérez-Peña, José Miguel Azañón, and Guillermo Booth-Rea
Jorge P. Galve et al.
  • Universidad de Granada, Granada, Spain (jpgalve@gmail.com)

The Camorro Fault is located at the foot of the northern slope of a limestone karstic massif that is called ‘Sierra de Las Chimeneas’, in the central sector of the Betic Cordillera (Southern Spain). The fault shows a well-marked surface expression. It is a 6 km-length strike-slip with extensional component fault that forms part of the Torcal Shear Zone. This fault can be continued 7 km eastward along the foot of northern slope of the ‘Torcal de Antequera’ (Málaga), World Heritage Site since 2016. The Camorro fault plane is well-exposed in some sectors while in others, the fault plane has been either affected by karstification processes or partially covered by talus deposits.

One of the most characteristic geomorphological features of the ‘Sierra de Las Chimeneas’ area is an impressive rock avalanche deposit, covering an area of 2.2 km2 and for which we estimated a volume of 0.48 Hm3. Given the characteristics of the rock avalanche deposit, we consider that it could be triggered by an earthquake on the Camorro Fault. This hypothesis is supported by other investigations that have already referred to quaternary paleoseismicity in this area. Previous archaeological research revealed a period of human occupation in a cave (‘Cueva del Toro’) located in the ‘Torcal de Antequera’ that point out evidences about the occurrence of a cataclysm in the late Copper Age (about 5000 years ago). Other studies have also suggested a possible connection between seismic events and megalith-building near Antequera. Beyond this, an archaeoseismic analysis in the megalithic site of Antequera (also World Heritage Site since 2016) found deformation structures probably linked to oscillations between the megalith orthostats during an earthquake. According to all of mentioned research, the Camorro Fault could be a good candidate to account for such prehistoric earthquake.

Further geochronological work remains to be done, specially focused on dating (e.g. by cosmogenic isotopes) the fault scarp of the Camorro Fault and the associated rock avalanche deposits. If cosmogenic and archaeological dates coincide, we could attribute all the mentioned observations to an earthquake of severe magnitude in an area where the population ignore that hazard. Thus, we could contribute not only to the history of human occupation of the World Heritage Site but also providing insights into the earthquake recurrence and seismic hazard of the region.

How to cite: Galve, J. P., Reyes-Carmona, C., Jabaloy, A., Ruano, P., Pérez-Peña, J. V., Azañón, J. M., and Booth-Rea, G.: Evidence of recent activity in the Camorro Fault (Central Betics, Southern Spain), EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19597, https://doi.org/10.5194/egusphere-egu2020-19597, 2020

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Presentation version 1 – uploaded on 07 May 2020
  • CC1: Comment on EGU2020-19597, Christoph Grützner, 08 May 2020

    Thanks for the very nice presentation.

    Do you have any plans for dating the rock avalanche deposits, and if so, how?
    Are you planning to trench the fault and what would you think is the best site for that?

    Thanks!

    • AC1: Reply to CC1, Cristina Reyes Carmona, 08 May 2020

      Hi Christoph, thank you for your feedback.

      Yes, our main plan is dating both the fault scarp and the avalanche deposits. Cosmogenic isotopes dating may be a good option. We have contacted with Klaus Reicherter and his team for such purpose. We have already planned to visit the area (as soon as possible...after the covid-19 crisis, I hope) and decide the viability of the dating there.

      About trenching, we have also considered it but at the momento, not as a priority. Maybe in a future!

      • CC2: Reply to AC1, Christoph Grützner, 08 May 2020

        Great, thanks for the explanation and good luck with the dating!