Controlled source audio-frequency magnetotellurics (CSAMT) data from the Douglas Basin near Douglas, Arizona, 2023-2026

Controlled source audio-frequency magnetotellurics (CSAMT) data were collected throughout the Douglas Basin, within Cochise County, Arizona, to better understand the hydrogeology of the area. CSAMT data provide vertical cross-section (profile) data about the resistivity of the subsurface, which may be related to lithologic boundaries and (or) grain-size distribution in the subsurface. CSAMT involves transmitting a current at various frequencies in one location, and measuring resistivity differences between electrodes spaced along a receiver line several kilometers from the transmitter. Data were collected using a GGT-30 transmitter and GDP32-II receiver (Zonge international. Inc..;

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). Data processing and inversions were carried out using Zonge International, Inc. software, DatPro Suite (CSAVGW, ver.1.2 and SCS2D, ver. 3.5). As a processing step, measured resistivity values must be "inverted", or converted to 2-d vertical resistivity profiles. 2D smooth-model inversion figures, JPG files created by Zonge International, Inc. software, depicting the modeled inversion data, can be downloaded from this page.

Raw data, station location data, and inversion data files are included in the .zip file on this page or can be downloaded individually from the child pages linked below.

Raw Data are text files output by the data-collection instrument (GDP32-II, Zonge International, Inc.) and averaged values are used in the inversion. These data may be useful for testing alternative inversion schemes.

Station Data are text files with the receiver locations for each line. Data were collected using a handheld GPS.

Inversion Data are text files of inverted resistivity values, starting model values, and corresponding x, y, z coordinates.