gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1994.58A.1.228 Investigating the Formation of the Active Tag Hydrothermal Mound Using Observational, Petrographic and Geochemical Data Humphris S. E. Tivey M. K. Thompson G. Woods Hole Oceanographic Institution, Woods Hole, MA 02543 Hannington M. D. Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, Canada K1A 0E8 Rona P. A. NOAA, Atlantic Oceanographic and Meteorological Laboratories, 4301 Rickenbacker Causeway, Miami, FL 33149 8 1994 58A 1 438 439 Copyright © 1994, The Mineralogical Society 1994