BOREHOLE-GEOPHYSICAL LOGGING PROGRAM AT THE UTAH GEOLOGICAL SURVEY

The Utah Geological Survey recently acquired borehole-geophysical logging equipment to increase the amount and quality of subsurface data for aquifers in the state. We seek to provide data that will be beneficial to state agencies, water-well drillers, and the general public. The logging equipment consists of a multi-parameter E-logging tool (that includes natural gamma, temperature, and standard electrical logs), a sonic tool, and a caliper tool. To date, we have logged wells in a variety of geologic materials in northern and central Utah, including shoreline and lake-bottom sediments from Lake Bonneville, alluvial-fan deposits, and bedrock, with depths extending up to 980 ft (300 m). We have assisted well drillers in locating fracture zones to target for development, recognizing areas of vertical flow within a well, and identifying intervals where water is flowing into and out of the well. The borehole-geophysical logs are made available to the public through the Utah Division of Water Rights Web site. An explanation of each log parameter aids the general public in understanding the interpretation of the logs.