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Mineral Resources > Online Spatial Data > Geology > by state > Nevada Geology

Geologic units in Elko county, Nevada

[Additional scientific data in this geographic area]

Breccia (Middle Eocene to Early Pliocene) at surface, covers < 0.1 % of this area

BRECCIA-Volcanic, thrust, and jasperoid breccia and landslide megabreccia

Lithology: volcanic breccia (agglomerate); tectonite; landslide

Argillaceous limestone, chert, and shale (Devonian) at surface, covers < 0.1 % of this area

ARGILLACEOUS LIMESTONE, CHERT, AND SHALE-Elko and Eureka Counties

Lithology: limestone; shale; chert; siltstone; sandstone

Upper Cambrian carbonate rocks in western Utah (Middle Cambrian to Early Ordovician) at surface, covers < 0.1 % of this area

Lithology: limestone; dolostone (dolomite); shale

Dolomite, limestone, and minor amounts of sandstone and quartzite (Devonian) at surface, covers 1 % of this area

DOLOMITE, LIMESTONE, AND MINOR AMOUNTS OF SANDSTONE AND QUARTZITE-Includes units such as Sevy and Simonson Dolomites, Guilmette and Nevada Formations, and Devils Gate Limestone.

Lithology: dolostone (dolomite); limestone; sandstone; quartzite; conglomerate; shale; chert

Andesite and basalt flows (Early Miocene to Early Pliocene) at surface, covers < 0.1 % of this area

ANDESITE AND BASALT FLOWS-Mostly in about 17 to about 6 m.y. age range. In Humboldt County, locally includes rocks as old as 21 m.y. May include rocks younger than 6 m.y. in places

Lithology: basalt; andesite; shoshonite

Siltstone, sandstone, limestone, and dolomite (commonly silty or sandy) and gypsum (Early Permian) at surface, covers 2 % of this area

SILTSTONE, SANDSTONE, LIMESTONE, AND DOLOMITE (COMMONLY SILTY OR SANDY), AND GYPSUM (Lower Permian)-Includes units such as Rib Hill Sandstone and Pequop Formation of Steele (1959) in Elko County, Rib Hill Sandstone and Arcturus Formation in White Pine County, Queantoweap Sandstone of NcNair (1951), Hermit Shale, and Coconino Sandstone in Clark and southern Lincoln Counties.

Lithology: sandstone; limestone; shale; siltstone; dolostone (dolomite); evaporite (gypsum); chert; quartzite

Older basalt rocks (Early Oligocene to Early Miocene) at surface, covers < 0.1 % of this area

OLDER BASALT ROCKS

Lithology: basalt; andesite

Limestone, dolomite, shale, and quartzite (Ordovician) at surface, covers 0.9 % of this area

LIMESTONE, DOLOMITE, SHALE, AND QUARTZITE-Includes units such as Pogonip Group, Eureka Quartzite, and Ely Springs Dolomite. Where Ely Springs Dolomite or equivalent rocks are included in SOc unit, this unit includes only the Pogonip Group and Eureka Quartzite or their equivalents.

Lithology: limestone; dolostone (dolomite); shale; quartzite; chert

Devonian sedimentary rocks in western Utah (Devonian to Mississippian) at surface, covers < 0.1 % of this area

Lithology: dolostone (dolomite); limestone; siltstone; mudstone

Tertiary (4) sedimentary rocks in western Utah (Middle Miocene to Late Pliocene) at surface, covers < 0.1 % of this area

Lithology: coarse-grained mixed clastic; alluvium; pyroclastic; basalt; evaporite

Rhyolitic flows and shallow intrusive rocks (Late Eocene to Middle Eocene) at surface, covers 0.7 % of this area

RHYOLITIC FLOWS AND SHALLOW INTRUSIVE ROCKS

Lithology: rhyolite; dacite; trachyte

Havallah sequence of Silberling and Roberts (1962) (Mississippian to Permian) at surface, covers 0.6 % of this area

HAVALLAH SEQUENCE OF SILBERLING AND ROBERTS (1962)-Chert, argillite, shale, greenstone, and minor amounts of siltstone, sandstone, conglomerate, and limestone. Includes Schoonover Formation of Fagan (1962) and Reservation Hill Formation in Elko County, Farrel Canyon Formation in southwestern Humboldt County, Havallah and Pumpernickel Formations in Pershing, Lander, and parts of Humboldt Counties, and rocks originally considered a part of the Pablo and Excelsior Formations in northern Nye, northern Esmeralda, and southern Mineral Counties. Assignment of some rocks to the Havallah sequence in the East Range, Pershing County, is highly uncertain. Includes rocks ranging in age from Late Mississippian to Early Permian

Lithology: shale; metavolcanic rock; chert; siltstone; sandstone; conglomerate; limestone

Older alluvial deposits (Miocene to Quaternary) at surface, covers 0.7 % of this area

OLDER ALLUVIAL DEPOSITS

Lithology: alluvium; lake or marine deposit (non-glacial)

Middle Cambrian shale and carbonate rocks in western Utah (Middle Cambrian) at surface, covers < 0.1 % of this area

Lithology: limestone; shale; dolostone (dolomite); argillite

Playa, marsh, and alluvial-flat deposits, locally eroded (Quaternary) at surface, covers 3 % of this area

PLAYA, MARSH, AND ALLUVIAL-FLAT DEPOSITS, LOCALLY ERODED

Lithology: playa; alluvium

Ash-flow tuffs and tuffaceous sedimentary rocks (Middle Miocene to Late Miocene) at surface, covers 1.0 % of this area

ASH-FLOW TUFFS AND TUFFACEOUS SEDIMENTARY ROCKS

Lithology: ash-flow tuff; rhyolite; sandstone; dacite; trachyte

Volcanic sandstone, felsic ash-flow tuffs, rhyolite, and rhyodacite flows (Middle Jurassic to Early Cretaceous) at surface, covers < 0.1 % of this area

VOLCANIC SANDSTONE, FELSIC ASH-FLOW TUFFS, RHYOLITE, AND RHYODACITE FLOWS (Upper? Jurassic)-Pony Trail Group of Cortez Mountains, Eureka County

Lithology: quartz latite; ash-flow tuff; rhyolite; wacke; rhyodacite

Shale, siltstone, sandstone, chert-pebble conglomerate, and limestone (Devonian to Mississippian) at surface, covers 2 % of this area

SHALE, SILTSTONE, SANDSTONE, CHERT-PEBBLE CONGLOMERATE, AND LIMESTONE-Includes units such as Pilot Shale, Joana Limestone, Chainman Shale, and Diamond Peak Formation in northern and eastern Nevada and Narrow Canyon Limestone, Mercury Limestone, and Eleana Formation in southern Nevada

Lithology: shale; limestone; siltstone; sandstone; conglomerate; dolostone (dolomite); chert; quartzite

Shale, chert, and minor amounts of quartzite, greenstone, and limestone (Ordovician) at surface, covers 1 % of this area

SHALE, CHERT, AND MINOR AMOUNTS OF QUARTZITE, GREENSTONE, AND LIMESTONE-Includes units such as Vinini Formation of north-central Nevada, Palmetto Formation in southern and central parts of Esmeralda County, and Comus Formation in Humboldt County. Locally includes rocks of Silurian and Devonian age.

Lithology: chert; shale; limestone; quartzite; andesite; siltstone; sandstone; chemical; greenstone; dolostone (dolomite)

Diorite (Jurassic to Cretaceous) at surface, covers < 0.1 % of this area

Lithology: diorite; quartz diorite; gabbro; granite; granodiorite; serpentinite

Rhyolitic flows and shallow intrusive rocks (Middle Miocene to Late Miocene) at surface, covers 7 % of this area

RHYOLITIC FLOWS AND SHALLOW INTRUSIVE ROCKS

Lithology: rhyolite; dacite; trachyte

Sedimentary rocks (Pliocene to Quaternary) at surface, covers 0.1 % of this area

SEDIMENTARY ROCKS-Mostly lake deposits

Lithology: lake or marine deposit (non-glacial); sedimentary rock

Alluvial deposits (Quaternary) at surface, covers 28 % of this area

ALLUVIAL DEPOSITS-Locally includes beach and sand dune deposits

Lithology: alluvium; mass wasting; dune sand; lake or marine deposit (non-glacial)

Chinle Formation and associated rocks (Late Triassic) at surface, covers < 0.1 % of this area

CHINLE FORMATION AND ASSOCIATED ROCKS (Upper Triassic)-Continental deposits of variegated bentonitic claystone, siltstone, and clayey sandstone; ledge-forming sandstone; and red siltstone

Lithology: claystone; siltstone; sandstone; gypsum; conglomerate; limestone

Welded and nonwelded silicic ash-flow tuffs (Late Eocene to Middle Eocene) at surface, covers 4 % of this area

WELDED AND NONWELDED SILICIC ASH-FLOW TUFFS-Locally includes thin units of air-fall tuff and sedimentary rock

Lithology: rhyolite; dacite; trachyte

Welded and nonwelded silicic ash-flow tuffs (Early Oligocene to Early Miocene) at surface, covers 0.9 % of this area

WELDED AND NONWELDED SILICIC ASH-FLOW TUFFS-Locally includes thin units of air-fall tuff and sedimentary rock

Lithology: rhyolite; dacite; trachyte

Dolomite and limestone (Middle Cambrian to Devonian) at surface, covers 0.4 % of this area

DOLOMITE AND LIMESTONE (Lower Paleozoic)

Lithology: marble; dolostone (dolomite); limestone; chert; quartzite

Rhyolitic intrusive rocks (Eocene to Miocene) at surface, covers < 0.1 % of this area

RHYOLITIC INTRUSIVE ROCKS

Lithology: granitoid

Granitic rocks (Jurassic) at surface, covers 0.8 % of this area

GRANITIC ROCKS-Mostly quartz monzonite and granodiorite

Lithology: quartz monzonite; granodiorite; granite; monzonite; quartz diorite; peraluminous granite

Quaternary alluvium and colluvium (Quaternary) at surface, covers < 0.1 % of this area

Lithology: alluvium; colluvium

Siltstone, shale, and limestone; Early Triassic marine to non-marine epicontinental deposits; southeastern Idaho (Early Triassic) at surface, covers < 0.1 % of this area

Lower Triassic shallow-marine to non-marine sediments; limestone and chert above shaley sandstone, siltstone, and limestone of eastern Idaho.

Lithology: siltstone; shale; limetstone; chert; dolostone (dolomite)

Ordovician sedimentary rocks in western Utah (Ordovician) at surface, covers < 0.1 % of this area

Lithology: limestone; fine-grained mixed clastic; sandstone; dolostone (dolomite)

Moenkopi Formation, Thaynes Formation, and related rocks (Early Triassic to Middle Triassic) at surface, covers 0.6 % of this area

MOENKOPI FORMATION, THAYNES FORMATION, AND RELATED ROCKS (Lower Triassic)-Marine deposits of siltstone, limestone, and sparse conglomerate

Lithology: shale; limestone; siltstone; sandstone; gypsum; dolostone (dolomite); conglomerate

Dolomite (Silurian to Early Devonian) at surface, covers < 0.1 % of this area

DOLOMITE-Includes units such as Laketown and Lone Mountain Dolomites. Locally includes rocks of Early Devonian age at top.

Lithology: dolostone (dolomite); limestone; chert; sedimentary breccia

Cherty limestone and sparse dolomite, shale, and sandstone (Permian) at surface, covers 2 % of this area

CHERTY LIMESTONE AND SPARSE DOLOMITE, SHALE, AND SANDSTONE (Lower and Upper Permian)-Includes units such as Park City Group and equivalent rocks in northern Nevada and Toroweap Formation and Kaibab Limestone in southern Nevada

Lithology: limestone; shale; dolostone (dolomite); sandstone; siltstone; chert; conglomerate; phosphorite; evaporite

Ash-flow tuffs, rhyolitic flows, and shallow intrusive rocks (Middle Miocene to Late Miocene) at surface, covers < 0.1 % of this area

ASH-FLOW TUFFS, RHYOLITIC FLOWS, AND SHALLOW INTRUSIVE ROCKS

Lithology: rhyolite; dacite; trachyte

Shale and thin-bedded or laminated limestone; also thinly interbedded limestone and chert (Middle Cambrian to Late Cambrian) at surface, covers < 0.1 % of this area

SHALE AND THIN-BEDDED OR LAMINATED LIMESTONE; ALSO THINLY INTERBEDDED LIMESTONE AND CHERT-Includes units such as Preble and Emigrant Formations

Lithology: shale; limestone; chert; siltstone; quartzite; diorite; conglomerate

Granitic rocks, central and eastern Nevada (Jurassic to Miocene) at surface, covers < 0.1 % of this area

GRANITIC ROCKS, CENTRAL AND EASTERN NEVADA-Mostly quartz monzonite and granodiorite. Inconclusively dated or not dated radiometrically

Lithology: quartz monzonite; granodiorite; granite; peraluminous granite

Antler Sequence of Silberling and Roberts (1962) (Pennsylvanian to Late Permian ) at surface, covers < 0.1 % of this area

ANTLER SEQUENCE OF SILBERLING AND ROBERTS (1962) (Middle Pennsylvanian to Early or Late Permian) (Guadalupian)-Conglomerate, sandy to conglomeratic limestone, limestone, sandstone, and calcareous shale. Thin detrital and carbonate sequence within main part of Antler orogenic belt. Includes units such as Sunflower Formation of Bushnell (1967) in Elko County, Battle Formation, Antler Peak Limestone, and Edna Mountain Formation in Lander and western Eureka Counties, and Wildcat Peak Formation in northern Nye County

Lithology: conglomerate; limestone; sandstone; siltstone; shale

Younger Precambrian metamorphic rocks in western Utah (Precambrian) at surface, covers < 0.1 % of this area

Lithology: conglomerate; metamorphic rock

Quartzite and minor amounts of conglomerate, phyllitic siltstone, limestone, and dolomite (Late Proterozoic to Early Cambrian) at surface, covers 0.3 % of this area

QUARTZITE AND MINOR AMOUNTS OF CONGLOMERATE, PHYLLITIC SILTSTONE, LIMESTONE, AND DOLOMITE-Includes Prospect Mountain Quartzite, Osgood Mountain Quartzite, and Gold Hill Formation in northern Nevada, and Stirling Quartzite, Wood Canyon Formation, and Zabriskie Quartzite in southern Nevada.

Lithology: quartzite; siltstone; dolostone (dolomite); limestone; phyllite; shale; conglomerate; sandstone

Basalt flows (Late Miocene to Middle Miocene) at surface, covers 0.4 % of this area

BASALT FLOWS

Lithology: basalt

Sandy and silty limestone, conglomerate, and siltstone (Pennsylvanian to Late Permian) at surface, covers 0.8 % of this area

SANDY AND SILTY LIMESTONE, CONGLOMERATE, AND SILTSTONE (Upper Pennsylvanian to Upper Permian)-Includes units such as Strathearn Formation of Dott (1955) and Buckskin Mountain, Beacon Flat, and Carlin Canyon Formations of Dott (1955)

Lithology: limestone; conglomerate; siltstone; sandstone; chert

Tertiary intrusive rocks in western Utah (Late Eocene to Early Miocene) at surface, covers < 0.1 % of this area

Lithology: granodiorite; granite; quartz monzonite; quartz diorite

Banbury Formation (Middle Miocene to Late Miocene) at surface, covers 7 % of this area

BANBURY FORMATION-Basalt, gravel, and tuffaceous sediments locally. Northeast Humboldt County and northwest Elko County

Lithology: basalt; gravel; sandstone

Limestone, sandstone, dolostone, and chert; Permian to Pennsylvanian marine epicontinental-basin deposits; southeastern Idaho; (Early Permian to Early Pennsylvanian) at surface, covers < 0.1 % of this area

Lower Permian to Lower Pennsylvanian chert, limestone, and sandstone of southern Idaho; subdivisions are (Ps, and PNs).

Lithology: limestone; sandstone; dolostone (dolomite); chert; siltstone; shale

Granitic rocks (Cretaceous) at surface, covers 0.7 % of this area

GRANITIC ROCKS-Mostly quartz monzonite and granodiorite

Lithology: granodiorite; quartz monzonite; granite; peraluminous granite

Welded and nonwelded silicic ash-flow tuffs (Middle Miocene to Late Miocene) at surface, covers 4 % of this area

WELDED AND NONWELDED SILICIC ASH-FLOW TUFFS-Locally includes thin units of air-fall tuff and sedimentary rock

Lithology: rhyolite

Miocene rhyolites (Middle to Late Miocene) at surface, covers < 0.1 % of this area

Lithology: rhyolite; dacite

Igneous and metamorphic complex (Paleozoic sedimentary rocks with Mesozoic intrusive rocks) at surface, covers 2 % of this area

IGNEOUS AND METAMORPHIC COMPLEX-Pegmatitic granite and other granitic rocks complexly intermixed with metasedimentary rocks. Considered to be Mesozoic igneous complex intruding lower Paleozoic and possibly Precambrian Z sedimentary rocks. Grades into units shown on map as lower Paleozoic. Ruby Mountains and East Humboldt Range, Elko County

Lithology: marble; schist; gneiss; quartzite; granulite; dolostone (dolomite); granite; pegmatite

Andesite and related rocks of intermediate composition (Early Oligocene to Early Miocene) at surface, covers 0.9 % of this area

ANDESITE AND RELATED ROCKS OF INTERMEDIATE COMPOSITION-Flows and breccias

Lithology: andesite; trachyte; dacite

Andesite and related rocks of intermediate composition (Late Eocene to Middle Eocene) at surface, covers 2 % of this area

ANDESITE AND RELATED ROCKS OF INTERMEDIATE COMPOSITION-Flows and breccias

Lithology: andesite; latite

Intrusive rocks of mafic to intermediate composition (Eocene to Miocene) at surface, covers < 0.1 % of this area

INTRUSIVE ROCKS OF MAFIC TO INTERMEDIATE COMPOSITION

Lithology: diorite; monzodiorite; quartz diorite; quartz monzogabbro; tonalite; gabbro

Rhyolitic flows and shallow intrusive rocks (Early Oligocene to Early Miocene) at surface, covers < 0.1 % of this area

RHYOLITIC FLOWS AND SHALLOW INTRUSIVE ROCKS

Lithology: rhyolite; dacite; trachyte

Sandstone, conglomerate, siltstone, tuff, claystone, limestone, and diatomite; Pliocene tuffaceous alluvial and lacustrine deposits; Snake River Plain and vicinity, southeastern Idaho (Pliocene ) at surface, covers < 0.1 % of this area

Pliocene stream and lake deposits; may be due to volcanic and block-faulting events.

Lithology: sandstone; conglomerate; siltstone; tuff; claystone; shale; limestone

Intrusive rocks of mafic and intermediate composition (Miocene to Quaternary) at surface, covers < 0.1 % of this area

INTRUSIVE ROCKS OF MAFIC AND INTERMEDIATE COMPOSITION

Lithology: andesite; rhyodacite; basalt; sedimentary rock

Platy limestone and limy siltstone, chert at base (Silurian to Early Devonian) at surface, covers 0.2 % of this area

PLATY LIMESTONE AND LIMY SILTSTONE, CHERT AT BASE-Includes units such as Roberts Mountains Formation, and Storff Formation and Chellis Limestone of Decker (1962). Locally includes rocks of Early Devonian age at top.

Lithology: limestone; dolostone (dolomite); chert; siltstone; shale

Phyllite, shale, and limestone (Middle Cambrian to Ordovician) at surface, covers 0.3 % of this area

PHYLLITE, SHALE, AND LIMESTONE-Locally includes chert and quartzite. Includes Tennessee Mountain Formation of Bushnell (1967) in western Elko County, Broad Canyon sequence of Means (1962) in Lander County, and rocks originally mapped as Palmetto Formation in Toiyabe and Toquima Ranges, northern Nye County

Lithology: shale; limestone; sandstone; chert

Shale, siliceous siltstone, chert, and minor amounts of limestone (Devonian) at surface, covers < 0.1 % of this area

SHALE, SILICEOUS SILTSTONE, CHERT, AND MINOR AMOUNTS OF LIMESTONE-Includes Cockalorum Wash Formation of northern Nye County and Woodruff Formation and unnamed rocks in Elko County

Lithology: shale; chert; limestone; siltstone; dolostone (dolomite); sandstone

Older Quaternary alluvial deposits (Quaternary) at surface, covers < 0.1 % of this area

Lithology: alluvium

Tuffaceous sedimentary rocks (Early Oligocene to Early Miocene) at surface, covers < 0.1 % of this area

TUFFACEOUS SEDIMENTARY ROCKS-Locally includes minor amounts of tuff

Lithology: sandstone; siltstone; limestone; conglomerate; mudstone; debris flow; landslide; tuff

Limestone, dolomite, and shale (Mississippian to Permian) at surface, covers 0.9 % of this area

LIMESTONE, DOLOMITE, AND SHALE (Upper Paleozoic)-Includes Van Duzer Limestone of Decker (1962)

Lithology: limestone; shale; sandstone; quartzite; siltstone; chert; conglomerate

Morainal deposits (Quaternary) at surface, covers 0.4 % of this area

MORAINAL DEPOSITS

Lithology: glacial drift

Aztec Sandstone (Early Jurassic) at surface, covers < 0.1 % of this area

AZTEC SANDSTONE (Triassic? And Jurassic)-Friable fine- to medium-grained sandstone with conspicuous large-scale cross strata; considered eolian. Age based on correlation with Navajo Sandstone

Lithology: sandstone

Siliceous and volcanic rocks (Ordovician to Devonian) at surface, covers 1 % of this area

SILICEOUS AND VOLCANIC ROCKS-Chert, shale, quartzite, greenstone, and minor amounts of limestone. Includes units such as Valmy Formation of north-central Nevada and some rocks mapped as Palmetto Formation in northern part of Esmeralda County and adjacent parts of Mineral and Nye Counties. Locally includes rocks of Silurian and Devonian age.

Lithology: chert; quartzite; shale; greenstone; limestone; conglomerate; siltstone; chemical

Silurian carbonate rocks in western Utah (Silurian) at surface, covers < 0.1 % of this area

Lithology: dolostone (dolomite); chert

Andesite and related rocks of intermediate composition (Late Miocene to Middle Miocene) at surface, covers 0.3 % of this area

ANDESITE AND RELATED ROCKS OF INTERMEDIATE COMPOSITION-Flows and breccias

Lithology: andesite; latite; trachyte; dacite

Gravel, sand, and silt; Quaternary basin-filling alluvium; Snake River Plain, Basin and Range provinces (Quaternary) at surface, covers < 0.1 % of this area

Quaternary detritus; generally basin-filling deposits of central and southern Idaho.

Lithology: alluvium; alluvial fan; alluvial terrace

Conglomerate, limestone, meta-andesite, phyllite, and shale (Devonian to Mississippian) at surface, covers 0.1 % of this area

CONGLOMERATE, LIMESTONE, META-ANDESITE, PHYLLITE, AND SHALE-Includes Grossman, Banner, Nelson, and Mountain City Formation. Northern Elko County

Lithology: schist; metavolcanic rock; conglomerate; sandstone; siltstone; phyllite; limestone; diabase

Chert, shale, argillite, siltstone, quartzite, and greenstone (Cambrian to Devonian) at surface, covers 0.5 % of this area

CHERT, SHALE, ARGILLITE, SILTSTONE, QUARTZITE, AND GREENSTONE-Undivided siliceous assemblage. Mostly Ordovician

Lithology: chert; quartzite; limestone; siltstone; conglomerate; shale

Quaternary Lake Bonneville deposits (Quaternary) at surface, covers < 0.1 % of this area

Lithology: clay or mud; sand; gravel; silt

Sedimentary rocks (Late Cretaceous to Oligocene) at surface, covers 0.8 % of this area

SEDIMENTARY ROCKS-Includes Sheep Pass Formation (Eocene) and related units and unnamed tuffaceous sedimentary rocks

Lithology: sandstone; conglomerate; limestone; siltstone; claystone; mudstone; shale; tuff; oil shale

Permian (1) sedimentary rocks in western Utah (Early Permian) at surface, covers < 0.1 % of this area

Lithology: sandstone; carbonate; fine-grained mixed clastic; evaporite

Shale, chert, and limestone (Ordovician) at surface, covers < 0.1 % of this area

SHALE, CHERT, AND LIMESTONE-Includes Aura Formation of Decker (1962) in northwest Elko County and Perkins Canyon Formation of Kay and Crawford (1964) in northern Nye County

Lithology: shale; chert; limestone; quartzite

Limestone, cherty limestone, sandy limestone, and chert-pebble conglomerate (Pennsylvanian) at surface, covers 0.2 % of this area

LIMESTONE, CHERTY LIMESTONE, SANDY LIMESTONE, AND CHERT-PEBBLE CONGLOMERATE (Lower and Middle Pennsylvanian)-Includes units such as Moleen and Tomera Formations of Dott (1955)

Lithology: limestone; conglomerate

Tuffaceous sedimentary rocks (Late Eocene to Late Miocene) at surface, covers 16 % of this area

TUFFACEOUS SEDIMENTARY ROCKS-Locally includes minor amounts of tuff

Lithology: sandstone; limestone; siltstone; conglomerate; mudstone; dolostone (dolomite); felsic volcanic rock; intermediate volcanic rock; mafic volcanic rock; tuff

Rhyolite, quartz latite, and latite ignimbrites and flows; Miocene felsic volcanics; Owyhee Plateau; (Miocene) at surface, covers < 0.1 % of this area

Miocene silicic flows, tuffs; most common in southwestern Idaho.

Lithology: rhyolite; latite; quartz latite; ignimbrite; lava flow

Granitic rocks (Paleocene to Late Miocene) at surface, covers 0.3 % of this area

GRANITIC ROCKS-Mostly quartz monzonite and granodiorite

Lithology: granodiorite; quartz monzonite; granite; monzonite

Cambrian quartzite in western Utah (Early Cambrian) at surface, covers < 0.1 % of this area

Lithology: arenite; conglomerate

Landslide deposits (Quaternary) at surface, covers 0.3 % of this area

LANDSLIDE DEPOSITS

Lithology: landslide; colluvium; sedimentary rock

Basalt flows, pyroclastic debris, clastic sediments, and diatomite; Pliocene basaltic volcanics and clastic sediments; Snake River Plain and vicinity (Pliocene) at surface, covers < 0.1 % of this area

Pliocene olivine basalt flows and associated tuff and detritus of southern Idaho.

Lithology: basalt; lava flow; tuff; mixed clastic/volcanic

Shale and chert (Silurian) at surface, covers < 0.1 % of this area

SHALE AND CHERT-Includes Fourmile Canyon Formation in Eureka County and Noh Formation of Riva (1970) and unnamed rocks in Elko County.

Lithology: shale; siltstone; chert; sandstone; limestone

Quaternary mud and salt flats (Holocene) at surface, covers < 0.1 % of this area

Lithology: mud flat; playa

Mississippian (1) carbonate rocks in western Utah (Mississippian) at surface, covers < 0.1 % of this area

Lithology: limestone

Continental deposits of siltstone, shale, conglomerate, and limestone (Cretaceous) at surface, covers < 0.1 % of this area

CONTINENTAL DEPOSITS OF SILTSTONE, SHALE, CONGLOMERATE, AND LIMESTONE-Includes units such as King Lear Formation in Humboldt County, Newark Canyon Formation in Eureka County, Willow Tank Formation and baseline Sandstone in Clark County

Lithology: conglomerate; sandstone; limestone; mudstone; siltstone

Silty limestone, minor amounts of shale, and some greenstone (Permian to Early Triassic) at surface, covers < 0.1 % of this area

SILTY LIMESTONE, MINOR AMOUNTS OF SHALE, AND SOME GREENSTONE-Unnamed sequence in Adobe Range, northern Elko County

Lithology: limestone; shale; greenstone

Quartzite, phyllitic siltstone, conglomerate, limestone, and dolomite (Late Proterozoic) at surface, covers < 0.1 % of this area

QUARTZITE, PHYLLITIC SILTSTONE, CONGLOMERATE, LIMESTONE, AND DOLOMITE-Includes McCoy Creek Group (excluding Stella Lake Quartzite) in east-central Nevada and Johnnie Formation in southern Nevada.

Lithology: quartzite; shale; conglomerate; siltstone; dolostone (dolomite)

Limestone and sparse dolomite, siltstone, and sandstone (Mississippian to Early Permian) at surface, covers 1 % of this area

LIMESTONE AND SPARSE DOLOMITE, SILTSTONE, AND SANDSTONE-Includes units such as undivided Riepe Spring Limestone of Steele (1960) and Ely Limestone or their equivalent in Elko, White Pine, and northern Lincoln Counties and most of the Bird Spring Formation and Callville Limestone in Clark and southern Lincoln Counties. Includes some stratigraphically higher Permian rocks in Leppy Peak, easternmost Elko County.

Lithology: limestone; sandstone; siltstone; chert; shale; dolostone (dolomite); conglomerate

Limestone and dolomite, locally thick sequences of shale and siltstone (Late Cambrian to Middle Cambrian) at surface, covers 0.4 % of this area

LIMESTONE AND DOLOMITE, LOCALLY THICK SEQUENCES OF SHALE AND SILTSTONE-Includes units such as Pioche Shale, Eldorado Dolomite, Geddes Limestone, Secret Canyon Shale, Hamburg Dolomite, Dunderberg Shale, and Windfall Formation of northern Nevada and Carrara, Bonanza King, and Nopah Formations of southern Nevada.

Lithology: limestone; dolostone (dolomite); shale; siltstone; sandstone; chert; conglomerate