Large salt beds on the surface of the Ross ice shelf near Black Island, Antarctica

An extensive system of mirabilite (Na₂SO₄.10H₂O) beds has been mapped on the Ross ice shelf near Black Island. The salt beds are normally underlain by a thin layer of mud and their surface is covered by a non-marine algal mat and boulder lag. These authors suggest the salt has been formed by the displacement of sub-ice-shelf brines to the ice-shelf surface. Evidence also suggests that other terrestrial mirabilite beds in the McMurdo Sound area were formed in the same manner and deposited by the Ross ice shelf during its Wisconsin retreat from McMurdo Sound.-from Authors