Thanks to a collaboration with colleagues at the Imperial college London, University of Napoli Federico II, University of Aberdeen, and Dalhousie University, we investigated the cross-evaporite fluid escape in the Eastern Mediterranean. You can read the paper here.
Despite salt being regarded as an extremely efficient, low-permeability hydraulic seal, an increasing number of cross-evaporite fluid escape features have been documented in salt-bearing sedimentary basins. Because of this, it is clear that our understanding of how thick salt deposits impact fluid flow in sedimentary basins is incomplete. We here examine the causes and evolution of cross-evaporite fluid escape in the northern Levant Basin, Eastern Mediterranean. High-quality 3D seismic data offshore Lebanon image hundreds of supra-salt fluid escape pipes distributed widely along the margin. The pipes consistently originate at the crest of prominent sub-salt anticlines, where overlying salt is relatively thin. The fact the pipes crosscut the salt suggests that hydrofracturing occurred, permitting focused fluid flow. Sequential pipes from unique emission points are organized along trails that are several kilometres long, and which are progressively deformed due to basinward gravity gliding of salt and its overburden. Correlation of pipes in 12 trails suggests 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 central basin area, in addition to gas exsolution from hydrocarbons already trapped in sub-salt anticlines, triggered seal failure and cross-evaporite fluid flow. We infer that other causes of fluid escape in the Eastern Mediterranean, such as subsurface pressure changes driven by sea-level variations and salt deposition associated with the Messinian Salinity Crisis, played only a minor role in triggering cross-evaporite fluid flow in the northern Levant Basin. Further phases of fluid escape are unique to each anticline and cannot be easily correlated across the margin. Therefore, despite a common initial cause, long-term fluid escape proceeded according to structure-specific characteristics, such as local dynamics of fluid migration and anticline geometry. Our work shows that the mechanisms triggering cross-evaporite fluid flow in salt basins vary in time and space.
Recently, Dr. Oppo et al. published a study on Scientific Reports where, by using methane-derived authigenic carbonates, they reconstruct the trends of methane emission from the global seafloor over the last 150 Ma (you can read it open access here). At the long geological time scale, the sea level change and the burial of organic matter have been identified as major controls on the methane release. The article has been showcased on a science news piece on EOS, published by AGU.
I am so glad to announce that the first graduate of my research group here at the School of Geosciences has been amazing at presenting her work on the Tuscaloosa Marine Shale at the AAPG ACE 2019! And now she’s heading out to a full time job at Shell in New Orleans! Great start for the Sedimentary Basins Research Group!
After a little bit of time, I’m pleased to see on-line the paper I was working on during the last year!
Together with Martin Hovland, we used multi-channel 3D and 2D seismic data to investigate the role of methane seepage during the initial phase of growth of isolated carbonate build-ups in the NW offshore of Australia.
Zachary got his BS in Geological Engineering from the University of Mississippi (2013) and soon after he started working for Halliburton as a logging geologist in the deep water Gulf of Mexico. Zachary is now pursuing a MS in Petroleum Geology at the School of Geosciences of UL Lafayette.
His thesis project will investigate the relationships between structural evolution and sediment dynamics in the offshore of Australia.
Applications are now being accepted for the new PhD program in Earth and Energy Science at the University of Louisiana at Lafayette! This new program prepares students to embrace an inter- and multi-disciplinary understanding of issues central to meeting the energy and environmental challenges of today and the future. For more information, see here!
I’m very pleased to be named Professor of the Month by the students at Theta Xi. It is always rewarding to see that the constant efforts made to be a better teacher are working and are recognized by the students.
Dr. Oppo will be attending the 2018 GSA meeting in Indianapolis.
Together with colleagues from Earlham College (IN) and the University of Aberdeen (UK), students Melody and Ai Lena will be presenting two posters on his recent research in Tanzania, Africa
Che M.*, Maselli V., Moore A., Mulaya E., Oppo D., Tomioka A.* (2018) – Stratigraphy of a tidal delta near Mbweni, Tanzania
Tomioka, A*, Che, M*, Maselli V., Moore A., Mulaya E., Oppo D. (2018) – SFM Sediment flux estimation on a tidal delta near Mbweni, Tanzania