Erratum to: Int J Earth Sci (Geol Rundsch) DOI 10.1007/s00531-015-1165-3

In the original publication of the article, the author P. van den Bogaard name was not included in the author group. The complete author group is given below.

J. Büchner, O. Tietz, L. Viereck, P. Suhr, M. Abratis, P. van den Bogaard.