The evolution of the natural temperature field of a salt dome in geological time

Geothermal anomalies develop at the top and the base of salt domes due to t he thermal conductivity contrast between rock salt and adjacent host rocks. The results of a numerical model to calculate the magnitude of these anoma lies of the salt dome Zwischenahn/North Germany during several stages of it s evolution are presented. The comparison of Zwischenahn with the larger sa lt dome Thonse-Wathlingen demonstrates the dependence of their magnitude on the width of the domes. Secondly, the temperature increase in a salt dome with depth correlates inversely with the width of the structure. In additio n, the extent of cooling of a salt dome during a climatic "cold stage" is p resented. In the presence of basal geothermal anomalies of salt domes, sign ificant lateral geothermal gradients in formations below the German Zechste in formation must exist.