Peter Bayliss, Chen Keqiao, Alan J. Griddle and George A. Desborough
Department of Geology and Geophysics, The University of Calgary, Alberta, Canada T2N IN4
Institute of Mineral Deposits, Chinese Academy of Geological Sciences, Beijing, P. R. China
Department of Mineralogy, Natural History Museum, Cromwell Rd., London SW7 2BD, U.K.
United States Geological Survey, Denver, Colorado, U.S.A.