“…Two geologic map reports were incorporated into this map (see "Index to geologic mapping" on map): the bedrock geologic map of the central block area by Day and others (1998) and the geologic.map of the Paintbrush Canyon area by Dickerson and Drake (1998) The locations of faults beneath the Quaternary surface deposits of Midway Valley and Yucca Wash were inferred from the groundbased gravity and magnetic surveys of Langenheim and others (1993), Langenheim and Ponce (1994), Ponce and others (1993), . A recent geophysical report on the Midway Valley and Yucca Wash areas by Ponce and Langenheim (1994) was also included.…”