Acknowledgement

We thank Gregor Hollmann for permission to use a modified version of his balanced section in Figure 3, and Manuel Sintubin for a thorough review of the manuscript, and for providing us with a copy of the abstract of Kenis et al. (2001). Thanks are due to Ulrich Kramm and Ralf Littke for discussions on the burial history in the area. One of the authors (JLU) wishes to thank B.L.M. Ottenhoff for assistance with obtaining the photograph of Figure 1b.