Filters: Tags: Saguache (X) > Extensions: ArcGIS Service Definition (X)

Filters Date Range Past year (0) Past month (0) Past week (0) Past day (0) Custom range... To   Search Types ArcGIS REST Map Service (1) ArcGIS Service Definition (1) Downloadable (1) Map Service (1) Contacts Joel E Robinson U.S. Geological Survey, ALASKA REGION Volcano Science Center U.S. Geological Survey - ScienceBase Joel E. Robinson More... Categories Data (1) Tag Types Place (1) Theme (1) Harvest Set (1) USGS Scientific Topic Keyword (1) Tag Schemes Common geographic areas (1) Alexandria Digital Library Feature Type Thesaurus (1) None (1) USGS Thesaurus (1) View Results as: JSON ATOM CSV

Database for the Geologic Map of the Bonanza Caldera Area, Northeastern San Juan Mountains, Colorado The San Juan Mountains in southwestern Colorado have long been recognized as a site of exceptionally voluminous mid-Tertiary volcanism, including at least 24 major ignimbrite sheets (each 150-5,000 km3) and associated caldera structures active at 33-23 Ma. More recent volcanologic and petrologic studies in the San Juan region have focused mainly on several ignimbrite-caldera systems: the southeastern area (Platoro complex), western calderas (Uncompahgre-Silverton-Lake City), the central cluster (La Garita-Creede calderas). The northeast San Juan region that was far less studied until recently occupies a transition between earlier volcanism in central Colorado and the larger-volume younger ignimbrite-caldera foci... Categories: Data; Types: ArcGIS REST Map Service, ArcGIS Service Definition, Downloadable, Map Service; Tags: Bonanza, Colorado, North America, Saguache, USGS Science Data Catalog (SDC), All tags... United States, Volcanology, caldera, explosive eruptions, geology, geology, volcanoes, Fewer tags