Mesozoic granite, quartz monzonite, granodiorite, and quartz diorite
Alluvium, lake, playa, and terrace deposits; unconsolidated and semi-consolidated. Mostly nonmarine, but includes marine deposits near the coast.
Tertiary volcanic flow rocks; minor pyroclastic deposits.
Quaternary pyroclastic and volcanic mudflow deposits.
Tertiary volcanic flow rocks; minor pyroclastic deposits.
Glacial till and moraines. Found at high elevations mostly in the Sierra Nevada and Klamath Mountains.
Tertiary pyroclastic and volcanic mudflow deposits.
Quaternary volcanic flow rocks; minor pyroclastic deposits; in part Pliocene and Miocene.
Undivided Mesozoic volcanic and metavolcanic rocks. Andesite and rhyolite flow rocks, greenstone, volcanic breccia and other pyroclastic rocks; in part strongly metamorphosed. Includes volcanic rocks of Franciscan Complex: basaltic pillow lava, diabase, greenstone, and minor pyroclastic rocks.
Recent (Holocene) pyroclastic and volcanic mudflow deposits; in part Pleistocene.
Sandstone, shale, limestone, dolomite, chert, quartzite, and phyllite; includes some rocks that are possibly Precambrian
Recent (Holocene) volcanic flow rocks; minor pyroclastic deposits; in part Pleistocene.
Sandstone, shale, conglomerate, chert, slate, quartzite, hornfels, marble, dolomite, phyllite; some greenstone
Quaternary volcanic flow rocks; minor pyroclastic deposits; in part Pliocene and Miocene.
Shale, sandstone, minor conglomerate, chert, slate, limestone; minor pyroclastic rocks
Undivided Cretaceous sandstone, shale, and conglomerate; minor nonmarine rocks in Peninsular Ranges
Conglomerate, shale, sandstone, limestone, dolomite, marble, gneiss, hornfels, and quartzite; may be Paleozoic in part
Undivided Paleozoic metasedimentary rocks. Includes slate, sandstone, shale, chert, conglomerate, limestone, dolomite, marble, phyllite, schist, hornfels, and quartzite
Undivided pre-Cenozoic metasedimentary and metavolcanic rocks of great variety. Mostly slate, quartzite, hornfels, chert, phyllite, mylonite, schist, gneiss, and minor marble.
Shale, sandstone, conglomerate, limestone, dolomite, chert, hornfels, marble, quartzite; in part pyroclastic rocks
Pliocene and/or Pleistocene sandstone, shale, and gravel deposits; in part Miocene.
Granitic and metamorphic rocks, mostly gneiss and other metamorphic rocks injected by granitic rocks. Mesozoic to Precambrian.
Tertiary pyroclastic and volcanic mudflow deposits.
Shale, sandstone, conglomerate, limestone, dolomite, chert, hornfels, marble, quartzite; in part pyroclastic rocks
Undivided Paleozoic metavolcanic rocks. Mostly flows, breccia and tuff, including greenstone, diabase, and pillow lavas; minor interbedded sedimentary rocks
Undivided pre-Cenozoic metavolcanic rocks. Includes latite, dacite, tuff, and greenstone; commonly schistose.
Gabbro and dark dioritic rocks; chiefly Mesozoic
Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Tertiary intrusive rocks; mostly shallow (hypabyssal) plugs and dikes. Includes some Mesozoic rocks.
Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Shale, conglomerate, limestone and dolomite, sandstone, slate, hornfels, quartzite; minor pyroclastic rocks
Schists of various types; mostly Paleozoic or Mesozoic age; some Precambrian.
Includes some rocks mapped as the Kate Peak and Alta Formations on the Washoe South map; Wahmonie and Salyer Formations on the Nye South map; Gilbert Andesite on the Esmeralda map; pyroxene, hornblende phenoandesite, and phenodacite on the Elko map; and other unnamed units. It corresponds to the unit Ta3 on the 1978 State map. It is present everywhere except Eureka and White Pine Counties.
Unit is present in all counties. Some counties divided the alluvium into younger and older units, and some did not. For those that did not, or used other generalized terms for Quaternary rocks, the unit Qal has been used for the general undivided alluvium. Additionally, when polygons have been edited and changed to alluvium, Qal was used as the general value; hence it now is present in all counties. Qya-Younger alluvium: Map unit is used in Churchill, Elko, Esmeralda, Eureka, Humboldt, Lander, and Lincoln Counties where geologic information suggests better-defined younger versus older alluvium. It is mostly interchangeable with Qal, except that it implies some specifically younger Quaternary deposits.
Granodiorite, granite, and related rocks make up the largest group of granitic intrusions exposed in Nevada. They are present in every county, and are especially abundant in west-central Nevada in an arcuate belt along the border with California extending north and eastward towards Idaho.
Poorly dated felsic intrusions described as granitic rocks, granite porphyry, granodiorite, quartz monzonite, and many undivided plutonic rocks are included here. They crop out in every county except Elko and northern Washoe.
Present in southern Washoe, Esmeralda, Lyon, Douglas, Carson, Mineral, and Lander Counties. It corresponds to unit QTa on the 1978 State map.
Olivine basalt and basaltic and andesitic rocks. This unit is present in Clark, Elko, Mineral, Esmeralda, Humboldt, Lincoln, Lyon, Douglas, Carson, Nye, Washoe, and Lander Counties. It corresponds to the 1978 State map unit QTb.
This assemblage is composed of Upper Triassic basinal-marine volcanic and carbonate rocks overlain by Lower Jurassic fine-grained, marine siliciclastic and tuffaceous sedimentary rocks, and by partly nonmarine sandstone, coarse clastic rocks, and volcanic rocks of late Early Jurassic and possibly younger age. This assemblage has stratigraphic similarities to the Luning-Berlin and Pamlico-Lodi assemblages, but shares only part of their late Mesozoic structural history, and is separated from them by the linear trace of the northwesterly trending Pine Nut fault (Oldow, 1984a; Silberling, Jones, and others, 1992). Structurally, the rocks are involved in only a single phase of tight to isoclinal folds with north-northwest striking axial planes, and no major internal thrust faults are known (Oldow, 1984a). The Pine Nut assemblage crops out in southern Washoe, Lyon, Douglas, Carson, and Mineral Counties, and includes rocks originally mapped as the Excelsior Formation, the Peavine sequence, and other metasedimentary and metavolcanic rocks.
Map unit used in all counties for recent lake beds, playas, and flood plains. Polygons from the 1978 State map unit Qp were added where no playa was shown on the county maps.
Concentrated in two areas of the State; common in the west-central part of the State along the California border in Mineral, Esmeralda, Lyon, Douglas, and Carson Counties. There is another more widely scattered group in eastern and central Nevada in Elko, Eureka, and White Pine Counties. Scattered occurrences also are present in Humboldt, Churchill, Lander, and Pershing Counties. Compositions are mainly granitic, granodiorite, and quartz monzonite.
Limestone, quartzite, dolomite, siltstone, conglomerate, and metamorphic rocks crop out in the southeastern, east-central, and northeastern regions of the State as part of Zqs. It forms the Proterozoic base of the continental margin stratigraphic section. This unit includes the Johnnie Formation in southern Nye and Lincoln Counties, schist in Elko County, the McCoy Creek Group metamorphic rocks in Elko and White Pine Counties, and the Wyman Formation in Esmeralda and southern Nye Counties. This rock is overlain by CZq. Its base is not exposed.
Unit is used for pre-Lake Lahontan deposits, weakly consolidated gravel and sand, older gravels, pediment gravels, and gravel deposits. It includes all units designated as QToa on the 1978 State map. This unit is used in all counties.
Rhyolitic flows, domes, plugs, breccias, quartz latite, rhyodacite, quartz porphyry dikes, and other shallow intrusive rocks. This unit includes rocks mapped as the Cañon Rhyolite on the Washoe North map, the Jarbidge Rhyolite and phenorhyolitic and phenodacitic flows and domes on the Elko County map, and other unnamed units. It has a distribution similar to Tt3, with exposures in the northern and southern parts of the State, but only crops out in a few places in the central region. It corresponds to unit Tr3 on the 1978 State map, and also includes a few rocks mapped as Trt on the 1978 State map. This unit is exposed in every county except White Pine.
Sediments are present in southern Washoe, northern Nye, Esmeralda, Elko, Humboldt, White Pine, and Lander Counties in high mountain ranges.
These lowermost Cambrian to Precambrian strata are scattered over much of central and eastern Nevada and form the base of the Phanerozoic part of the continental margin stratigraphic section. They include the Campito, Deep Spring, Harkless, and Poleta Formations, and the Reed Dolomite in Esmeralda County; the Gold Hill Formation in northern Nye County; unnamed quartzite and shale in White Pine County; the Osgood Mountain quartzite in Humboldt County; the Prospect Mountain Quartzite in northern Nye, Lincoln, Eureka, and Elko Counties; unnamed quartzite and shale in Lander and Clark counties; and the Stirling Quartzite, Wood Canyon Formation, and Zabriskie Quartzite in southern Nye County. In a number of places, these rocks are depositional on Late Proterozoic unit Zqs. In southernmost Clark County, CZq is lying unconformably directly on Early Proterozoic gneiss (Xm). In the east-central part of Nevada, CZq is overlain depositionally by Cambrian carbonate (Cc) of the Carbonate shelf sequence. In the Nolan belt, these rocks are depositionally overlain by unit Ctd. In the Osgood Mountains in Humboldt County, Permian and Pennsylvanian rocks of the Siliciclastic overlap assemblage (PIPacl, Pacl) rest unconformably directly on the Osgood Mountain Quartzite.
Unit is mixed on the Washoe North map with basalt, tuff, diatomite, and tuffaceous sediments. It includes the units mapped as Qls from the 1978 State map. It is present in Churchill, Washoe, Nye, Esmeralda, Elko, Eureka, Humboldt, Lander, Lincoln, Mineral, and Pershing Counties.
Includes units mapped as the High Rock sequence on the Washoe North map; the Timber Mountain, Paintbrush, Crater Flat, and Belted Range Tuffs, and Indian Trail Formation (now abandoned) on the Nye South map; the Thirsty Canyon Tuff on the Nye South and Esmeralda maps; and other unnamed units. Locally it includes tuffaceous sedimentary rocks interstratified with tuffs. It is present in the northernmost part and southernmost parts of the State, and is not exposed in the central region. It corresponds to unit Tt3 on the 1978 State map, although a few rocks also mapped as Trt on the 1978 State map also are included. It is present in Clark, Churchill, Washoe, Nye, Lincoln, Lyon, Douglas, Carson, Esmeralda, Elko, Humboldt, Pershing, and Mineral Counties.
Present in Esmeralda, Elko, Mineral, Lyon, Douglas, Carson, and Eureka Counties and corresponds to unit QTs on the 1978 State map.
Tuffaceous and other young Tertiary sedimentary rocks. Most of these rocks are sedimentary with a strong volcanic component - a few are tuffaceous with a strong sedimentary component. This unit includes rocks originally mapped as the High Rock sequence in Washoe County; the Horse Camp Formation in northern Nye County; the Esmeralda Formation in Mineral and Esmeralda Counties; older lake beds in Lincoln County; the Belted Range Tuff; the Indian Trail Formation (now abandoned); Timber Mountain, Paintbrush, and Crater Flat Tuffs; Wahmonie and Salyer Formations in southern Nye County; the Siebert Tuff in Esmeralda County; the Muddy Creek Formation in Clark County; and the Thousand Creek and Virgin Valley “beds” in Humboldt County; and other unnamed units. It corresponds to units Ts3 and Tts from the 1978 State map. It is present in all counties.
The Gold Range assemblage consists of mainly nonmarine, terrigenous clastic, and volcanogenic rocks of probable Late Triassic to Middle Jurassic ages, and local volcanic rocks having younger Mesozoic radiometric ages (Silberling, 1991). It is lying with angular unconformity over Permian rocks included in the Golconda terrane (GC). The oldest rocks are interbedded, subaerial and shallow-marine terrigenous clastic, volcaniclastic, and minor carbonate rocks overlain by shelf carbonates containing Early Jurassic pelecypods. Unfossiliferous quartz arenite and coarse clastic rocks disconformably overlie the shelf carbonate and grade upward into poorly sorted volcanogenic sandstone and coarse clastic rocks (Oldow, 1984a; Oldow and Bartel, 1987). The assemblage is deformed by northeast-trending folds associated with the overlying Luning thrust as well as younger northwest-trending folds (Oldow, 1984a). Archbold and Paul (1970) named these rocks the Gold Range Formation. They were originally mapped as the Luning Formation and in a few cases, the Excelsior Formation by early workers (Archbold and Paul, 1970, p. 6). Speed (1977a) later modified the definition of the Gold Range Formation. Oldow (1981) included some of these rocks in the Water Canyon assemblage. These rocks were included with the Paradise terrane (Silberling, Jones, and others, 1987; Silberling, Jones, and others, 1992), but have been separated here in agreement with Silberling (1991). Silberling (1991) used “Gold Range terrane” to include the unconformably underlying Permian rocks of the Mina Formation. Since the basement rocks are here included with the Golconda terrane, the term “Gold Range assemblage” is used only for the Mesozoic rocks unconformably overlying the Permian basement. The Gold Range assemblage is in the same tectonostratigraphic position as the Humboldt assemblage - both are overlying rocks of the Golconda terrane with a strong angular unconformity. While these assemblages are similar in overall age, they have different stratigraphic sequences and thus paleogeographic settings. The exact stratigraphy of the Gold Range assemblage and whether or not it includes younger Cretaceous volcanic rocks (Silberling, Jones, and others, 1987; Stewart, 1980) is not clear. This assemblage crops out in Esmeralda, Mineral, and northern Nye Counties.