*Corresponding author, e-mail: rena.gradmann@gmx.de

We have discovered a severe error in this article. Unfortunately the second author, Christoph Berthold, was not listed in the submitted manuscript and, consequently, not in the printed version or in the original online pdf-file of the article. The correct listing of authors is given below. An updated pdf-version of the article is available as download from the EJM web pages. We ask the readers of the EJM for attention to this correction and apologize for this mistake.

The authors and addresses shall read:

Rena GRADMANN1,*, Christoph BERTHOLD2, Ulrich SCHÜSSLER1

1Department of Geodynamics and Geomaterial Research, University Würzburg, Am Hubland, 97074 Würzburg, Germany

*Corresponding author, e-mail: rena.gradmann@gmx.de

2Department of Applied Mineralogy, University Tübingen, Wilhelmstrasse 56, 72074 Tübingen, Germany