Hi Joseph, a low-viscosity silicone putty is often used to simulate salt layers. You must search for a putty with Newtonian behaviour at low strain, as salt behaves.

There is an excelent and classic publication on the subjetc: Article Flow behaviour and physical chemistry of bouncing putty and ...

Thank you Marco. I will use your advise.

Hi Joseph, as Marco eluded to, a silicon putty works great. I used some to model salt diapirism a while back, burying the putty with some beach sand. Just the weight of a small cover of sand was enough to allow the 'salt' to flow. Hope that helps.

Hi Nicholas, thank you very much, I am sure that your experience in modeling would be helpful. I will be grateful, if you send me some picture of your experience.