Throughout Nevada the most reliable stratigraphic datum in sequences of non-marine Cenozoic sedimentary rocks is a distinctive suite of tuffaceous upper Miocene to middle Pliocene deposits. For convenience of discussion these rocks are referred to as the vitric tuff unit.

In eastern Nevada and adjacent Utah the vitric tuff unit is locally underlain by red and tan Paleozoic-pebble conglomerate, some of which is as old as Cretaceous. Scattered outcrops of lower Cenozoic (largely Eocene) limestone and associated reddish brown conglomerate in east-central Nevada and western Utah probably are equivalent to the Wasatch formation in Utah. A distinctive sequence of limestone and oil shale found locally in northeastern Nevada probably is Oligocene in age.

Over an extensive part of southern, central, and western Nevada, as well as locally in the northeastern part of the state, rocks below the vitric tuff unit are essentially rhyolitic to dacitic agglomerate and coarse tuff, welded tuff, and lava. This sequence apparently accumulated principally between Oligocene and late Miocene time and was associated in a general way with important deformation of the region that faulted and tilted older Cenozoic sequences.

Following a middle Cenozoic episode of deformation and erosion, the vitric tuff unit, consisting chiefly of soft unaltered tuff, bentonitic mudstone, sandstone, limestone, and diatomite, began to accumulate in late Miocene time in southern, central, and western Nevada while deposits of limestone, carbonaceous and bituminous shale, sandstone, and conglomerate, containing partly altered tuffaceous debris, formed in northeastern Nevada. In early Pliocene time, during an episode of extensive aggradation accompanied by eruption of the younger Sierran and southern Cascade andesitic rocks, the vitric tuff facies accumulated throughout most of the state, and it continued to accumulate locally in middle Pliocene time.

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Important uplift of the Sierra Nevada accompanied large-scale block-faulting and regional uplift that began in later Pliocene time and produced the present structual and topographic pattern of Nevada.

Even though a middle Cenozoic and a post-early to middle Pliocene episode of deformation may have predominated throughout much of the state, local areas had varying tectonic and depositional histories during the Cenozoic era.