The Manix Fault is an east-northeast trending zone of anastomosing fractures located 21 to 35 miles east of Barstow in the east-central Mojave Desert of California. The Manix Fault cuts Mesozoic(?) crystalline basement rocks, Miocene and post-Miocene volcanic rocks, pos t-volcanic fanglomerates, and late Pleistocene Manix Lake beds. Movement along the fault may have begun as early as late Tertiary.s evidenced by possible intermittent faulting in a post -Miocene fanglomerate unit, but definitely has been active in the Quaternary, as evidenced by faulted late Pleistocene lake beds and recent earthquakes (April 10, 1947). Sense and magnitude of slip along the fault are unertain; however, left-lateral separation of as much as three miles may be indicated by a faulted post-Miocene granitic-clast fanglomerate in the northern Cady Mountains.