Multi-proxy characterization of the Messinian Salinity Crisis deposits in the Sorbas Basin (SE Spain): Implications on the paleo-environmental evolution during the uppermost Miocene
- 1Department of Hydrogeology, University of Corsica Pasquale Paoli, Corte, France
- 2Géosciences Montpellier, Université de Montpellier, CNRS, Montpellier Cedex 05, France
- 3Departamento de Estratigrafía y Paleontología, Universidad de Granada, Avenida de la Fuente Nueva S/N, 18071 Granada, Spain
- 4Departamento de Geología, Univ. de Salamanca, Plaza de los Caídos s/n, 37008 Salamanca, Spain
- 5National Institute of Oceanography and Applied Geophysics OGS, Trieste, Italy
- 6Université de Paris, Institut de physique du globe de Paris, CNRS, F-75005 Paris, France
The Sorbas Basin (Spain) has been a key study area for the understanding of the Late Miocene Messinian Salinity Crisis (MSC) (5.97-5.33 Ma). The MSC deposits of the Sorbas Basin consist of four sedimentary units: (1) the pre-MSC Abad marls topped by (2) the evaporitic Yesares gypsum member, followed by two non-evaporitic units known as the (3) Sorbas and (4) Zorreras members. These deposits have been widely studied almost exclusively in the several outcrops across the basin.
In 2021, four ~175m-long boreholes (named SG0, 1, 2 and 3) covering most of the MSC sequence were drilled, cored, and logged in the Marylen gypsum mine in Sorbas. These successions provided for the first time a continuous, non-outcropping succession of the MSC record. In addition to the recovered cores (~75% recovery), downhole geophysical logging data was obtained from the four holes and digital images of the area were collected with a drone.
Optical borehole wall images provide mm-scale images of the borehole walls, highlighting the sedimentological and structural characteristics of the deposits. Downhole geophysical measurements included acoustic velocity, electric resistivity and magnetic susceptibility, and natural spectral gamma ray. In addition to the petrophysical logs, a Vertical Seismic Profile, including a walk-away distributed acoustic sensing experiment, was acquired in holes SG2 and SG3.
Preliminary results confirmed not only the astronomical precession-driven cyclicity observed elsewhere in the Messinian gypsum, but also potentially higher-frequency cyclicity in the post-evaporitic Sorbas Mb. The Digital Outcrop Model allowed for a detailed correlation between the wells while recognizing various discontinuities and obtaining 3D data of geometry and dimensions of the different geobodies that respond to the interaction of auto and allocyclic processes that conditioned erosion and sedimentation in this western sector of the Mediterranean.
How to cite: Raad, F., Pezard, P., Viseras, C., Sierro, F. J., Yeste, L. M., Schleifer, A., Lofi, J., Camerlenghi, A., and Aloisi, G.: Multi-proxy characterization of the Messinian Salinity Crisis deposits in the Sorbas Basin (SE Spain): Implications on the paleo-environmental evolution during the uppermost Miocene, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-22572, https://doi.org/10.5194/egusphere-egu24-22572, 2024.
