1. C. M. Rubin, Department of Geology, Central Washington University, Ellensburg, WA 98926, USA. S. C. Lindvall, William Lettis and Associates, 27201 Tourney Road, Suite 201-B, Valencia, CA 91355, USA. T. K. Rockwell, Department of Geological Sciences, San Diego State University, San Diego, CA 92182, USA.