Br profile for the Stassfurt rock salt of the Gorleben salt dome

The absolute Br content of the vertical profile for the Stassfurt rock salt of the Gorleben salt dome correspond to the Br proportions in the Stassfurt rock salt in the entire area of distribution of Zechstein evaporite in Central and North Germany. This finding applicable to the main area of the Gorleben salt dome is proof that in the hitherto investigated parts of the Gorleben salt dome between about 800 and 1600 m below the surface of the earth the original mineralogical and geochemical material of the Stassfurt rock salt has remained largely unchanged since its formation about 250 mill. years ago. Ground waters (formation waters) external to the evaporite from the overburden and/or enclosing rocks of the evaporite mass have thus not become effective over a large area. The function of the Stassfurt rock salt in the present main area of the Gorleben salt dome as a natural barrier and thus also the isolation potential of the rock salt has been maintained virtually unchanged during geological eras despite different processes on the surface and underground.