A [[formation resistivity factor|formation resistivity]] log made from a system consisting of both very deep and shallow investigative guard log schemes. The tool records, in combination, deep and shallow guard log curves and a [[gamma ray]] and/or [[SP]] [[curve]]. The dual guard-FoRxo is a simultaneously recorded dual guard log and [[FoRxo log|FoRxo]]. See also [[guard log]] and [[FoRxo log]].