Airborne electromagnetic, magnetic, and radiometric survey, upper East River and surrounding watersheds near Crested Butte, Colorado, 2017

This data release consists of 1,984 line-kilometers of airborne electromagnetic (AEM), magnetic data and radiometric data collected from October to November 2017 in the upper East River and surrounding watersheds in central Colorado. The U.S. Geological Survey contracted Geotech Ltd. to acquire these data as part of regional investigations into the geologic structure and hydrologic framework of the area. The AEM data have been inverted to produce a series of regional cross-sections that constrain the electrical properties of the subsurface to a depth of ~500m. Data were acquired using the VTEM ET time-domain helicopter-borne electromagnetic system along flight lines that cross important geological structures over a 483 square kilometer area. In addition to magnetic and radiometric data, this data release includes minimally processed AEM data, processed AEM data used in the development of resistivity and induced polarization (IP) models, and laterally constrained inverse models for resistivity and IP parameters along all flight lines. Data that intersected cultural infrastructure have been removed from the processed AEM data prior to inversion. The data provided in this section include minimally processed (raw) AEM data and unprocessed and processed magnetic data. Digital data are described in the data dictionary and the complete data package from the contractor is included in a zip file and described in the contractor's report.