Salt and Methane Generation Initiated by Membrane Polarisation

The existence of deep marine hypersaline anoxic basins (DHAB) has been well-documented starting with the MedRiff Project in the Eastern Mediterranean. We suppose that there is analogy between the recent and ancient DHABs. This premise allows us to hypothesize that some methane accumulations in geological reservoirs may have been generated by historical euryhaline bacteria. The extreme life conditions of the bacteria and the facieses, as found in currently existing supersaturated salt brines DHABs, may have also existed in the geological past. Since salt basins overlap some of the most productive gas provinces, this article aims to introduce a new approach to salt and methane generation. It highlights the need to reconsider the classical approach to salt and methane generation due to new observations. Hereby we describe a new mechanism for DHAB generation due to membrane polarization. These phenomena generate a surface on which seawater of normal salinity meets the underneath brine of high salinity, and there is no diffusion between them. Hence we presume that non-crystalized, over-pressured, salty brine is the appropriate material to trap and host methane. Following overburden by deposited basin sediments, this viscous, gas-saturated brine can be an engine for diapir formation, which is prior to the crystalline phase. This new idea redefines our search for salt and methane deposits yet it requires further research and consideration, along with the new approach of salt diapir formation in specific salt basins.