The Yucca Flat area is divided by the Tippinip fault, a high-angle reverse fault, into eastern and western units. The eastern unit is composed chiefly of upper Precambrian to middle Paleozoic rocks that have been folded into the west-northwest-trending Halfpint anticline; major faults trend northwest and dip steeply. The western unit is composed chiefly of middle and upper Paleozoic rocks compressed into five northeast-trending folds and cut by numerous normal and reverse faults. Projections of the Tippinip fault and the CP and Mine Mountain thrust faults beneath Yucca Flat have been inferred from drill-hole and geophysical data.
Folds and faults control the location of two and possibly all three of the Mesozoic granitic intrusives that invade upper Precambrian and lower Paleozoic rocks in the northern part of the area. In the eastern unit, the Climax stock crops out on the crest of the Halfpint anticline, where it is truncated by the Tippinip fault. The Twinridge intrusive also crops out on the crest about 7 miles southeast. In the western unit, the Gold Meadows stock intrudes Cambrian and Precambrian rocks that are probably part of a poorly exposed thrust plate.
Many of the younger faults — the high-angle normal faults that cut Tertiary volcanic rocks and Quaternary alluvium — are probably related to subsidence of the Yucca Flat alluvial basin. A few of them are the outermost faults of the ring-fracture zone of the collapsed Timber Mountain caldera.