Acknowledgements
The authors would like to thank Ronny Meijers and Louis Swinkels from Museum Het Valkhof in Nijmegen, and Else Hartoch and Guido Creemers from the Gallo-Romeins Museum in Tongeren for kindly supplying samples. Hans Postma is thanked for his valuable contributions to this paper. David Fontijn and Maikel Kuijpers from the Archaeology department from Leiden University have been very helpful with various archaeological issues, for which the authors are grateful.
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Janneke Nienhuis
Delft University of Technology, department Materials Science and Engineering
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Jilt Sietsma
Delft University of Technology, department Materials Science and Engineering
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Stijn Arnoldussen
Groningen Institute for Archaeology, Groningen University
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Review data:
Submission 6/12/2010
Revision 23/5/2011
2nd submission 7/6/2011
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