EGU21-2545
https://doi.org/10.5194/egusphere-egu21-2545
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Leaky salt: pipe trails record the history of cross-evaporite fluid escape in the northern Levant Basin, Eastern Mediterranean

Davide Oppo1, Sian Evans2, Christopher A-L Jackson3, David Iacopini4, SM Mainul Kabir5, and Vittorio Maselli6
Davide Oppo et al.
  • 1University of Louisiana at Lafayette, Sedimentary Basins Research Group, School of Geosciences, Lafayette, United States of America (davide.oppo@louisiana.edu)
  • 2Department of Geosciences, University of Oslo, Oslo, Norway
  • 3Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
  • 4Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse (DiSTAR), Universita di Napoli Federico II, Napoli, Italy
  • 5School of Geosciences, University of Aberdeen, Aberdeen, UK
  • 6Department of Earth and Environmental Sciences, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada

Hydrocarbon escape systems can be regionally active on multi-million-year timescales. However, reconstructing the timing and evolution of repeated escape events can be challenging because their expression may overlap in time and space. In the northern Levant Basin, eastern Mediterranean, distinct fluid escape episodes from common leakage points formed discrete, cross-evaporite fluid escape pipes, which are preserved in the stratigraphic record due to the coeval Messinian salt tectonics.

The pipes consistently originate at the crest of prominent sub-salt anticlines, where thinning and hydrofracturing of overlying salt permitted focused fluid flow. Sequential pipes are arranged in several kilometers-long trails that were progressively deformed due to basinward gravity-gliding of salt and its overburden. The correlation of the oldest pipes within 12 trails suggests that margin-wide fluid escape started in the Late Pliocene/Early Pleistocene, coincident with a major phase of uplift of the Levant margin. We interpret that the consequent transfer of overpressure from the deeper basin areas triggered seal failure and cross-evaporite fluid flow. We infer that other triggers, mainly associated with the Messinian Salinity Crisis and compressive tectonics, played a secondary role in the northern Levant Basin. Further phases of fluid escape are unique to each anticline and, despite a common initial cause, long-term fluid escape proceeded independently according to structure-specific characteristics, such as the local dynamics of fluid migration and anticline geometry.

Whereas cross-evaporite fluid escape in the southern Levant Basin is mainly attributed to the Messinian Salinity Crisis and compaction disequilibrium, we argue that these mechanisms do not apply to the northern Levant Basin; here, fluid escape was mainly driven by the tectonic evolution of the margin. Within this context, our study shows that the causes of cross-evaporite fluid escape can vary over time, act in synergy, and have different impacts in different areas of large salt basins.

How to cite: Oppo, D., Evans, S., Jackson, C. A.-L., Iacopini, D., Kabir, S. M., and Maselli, V.: Leaky salt: pipe trails record the history of cross-evaporite fluid escape in the northern Levant Basin, Eastern Mediterranean, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2545, https://doi.org/10.5194/egusphere-egu21-2545, 2021.

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