Research Article| July 01, 2008 Eruptive and noneruptive calderas, northeastern San Juan Mountains, Colorado: Where did the ignimbrites come from? Peter W. Lipman; Peter W. Lipman † 1MS 910, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA †E-mail: plipman@usgs.gov Sea...