1. Institute of Geology
and Geochemistry
of Petroleum and Coal, RWTH Aachen University, Lochnerstrasse 4-20, D-52056 Aachen, Germany
2. Clay and Interface Mineralogy, RWTH Aachen University, Bunsenstrasse 8, D-52072 Aachen,
Germany
3. OMV Exploration and Production GmbH, Trabrennstrasse 6-8, 1210 Vienna, Austria