Airborne electromagnetic (AEM) and magnetic survey data were collected during April and May 2019 along 1,467 line-kilometers in the San Juan-Silverton Caldera complex, Colorado, in the Southern Rocky Mountain Volcanic Field. Data were acquired by Geotech, Ltd. with the versatile time-domain electromagnetic (VTEM-ET) system together with a Geometrics optically pumped cesium vapor magnetometer. The survey was flown at a mean flight height of 140 meters (m) above terrain in various line directions and line spacings ranging from 150 m to 600 m. Multiple variable-spaced lines were flown along rivers and streams in the survey area. USGS provided the contractor with the San Juan National Forest Lidar Point Cloud elevation dataset imported from the USGS National MAP 3D Elevation Program (U.S. Geological Survey, 2019). AEM data were inverted to produce models of electrical resistivity along flight paths.
References:
U.S. Geological Survey, The National Map, 2019, 3DEP products and services: The National Map, 3D Elevation Program Web page, accessed April 2019 at https://nationalmap.gov/3DEP/3dep_prodserv.html
First posted September 16, 2020
Revised August 19, 2022, ver.2.0
Changes in version 2.0:
1. Updated contractor package and raw data to remediate an erroneous calculation of transmitter/receiver altitude.
2. Converted dataset to netCDF format.
3. Added inverted resistivity models for the entire dataset.
