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Geologic units containing lava

Idaho

Basalt flows and incidental andesite, and latite flows; Miocene mafic to intermediate volcanics; subunits are Tmib, Tm1b, Tm2b, Tm3b; Columbia Plateau, Owyhee Plateau (Miocene)

Miocene plateau basalt flows of western Idaho; subdivisions are (Tm3b, Tm2b, Tm1b).

Dacite to rhyolite (or rhodacite) ignimbrites; Eocene rhyodacitic cauldron complex; east-central Idaho, central Challis volcanic field (Eocene)

Eocene mixed silicic and basaltic volcanic ejecta, flows and reworked debris.

Rhyolite, andesite, dacite, quartz latite; Oligocene to Eocene volcanics; northern Idaho; (Paleogene, possibly Oligocene)

Lower Tertiary, possibly Oligocene, flows and tuffs of northern Idaho.

Rhyolite flows and ignimbrites; Late Pleistocene felsic volcanics of subunit 3f; Yellowstone Plateau (Late Pleistocene)

Upper Pleistocene silicic volcanic unit 3 in eastern Idaho.

Rhyolite ignimbrites, basalt flows, andesitic flows and tuffs, mudstone, conglomerate, and limestone; Quaternary to Tertiary volcanics and sediments; east-central Idaho (Pliocene)

Pliocene silicic welded tuff, ash, and flow rock; most common in southwestern Idaho.

Rhyolite ignimbrites, latite and basalt lava flows, late Eocene rhyolitic ignimbrite cauldron complex; east-central Idaho, northern Challis volcanic field (Eocene)

Eocene mixed silicic and basaltic volcanic ejecta, flows and reworked debris.

Rhyolite ot trachyte ignimbrites and flows; Pliocene felsic volcanics; eastern Snake River Plain and vicinity (Pliocene)

Pliocene silicic welded tuff, ash, and flow rock; most common in southwestern Idaho.

Rhyolite, quartz latite, and latite ignimbrites and flows; Miocene felsic volcanics; Owyhee Plateau; (Miocene)

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

Rhyolitic domes, flows, pyroclastic debris, and basalt flows; Early Pleistocene subvolcanic to volcanic features; eastern Snake River Plain (Early Pleistocene)

Lower Pleistocene to Pliocene silicic volcanic units near the Snake Plain.

Shale, arenite, conglomerate, intermediate and felsic volcanic rocks; Late Proterozoic rifted continental margin; southeastern Idaho (Late Proterozoic)

Younger Precambrian volcanic and diamictic units of central and southeastern Idaho.

Trachyandesite, latite, trachybasalt flows, dikes, and volcaniclastic debris; Eocene intermediate volcanics; central Idaho, southern Challis volcanic field (Eocene)

Eocene mixed silicic and basaltic volcanic ejecta, flows and reworked debris.

Michigan

Copper Harbor Conglomerate (Middle Proterozoic)

Copper Harbor Conglomerate - Red lithic conglomerate and sandstone; mafic to felsic volcanic flows similar to those of the unnamed formation (unit Yu) are interlayered with the sedimentary rocks.

Montana

Tertiary sedimentary rocks, undifferentiated (Phanerozoic | Cenozoic | Tertiary)

Tertiary sedimentary rocks, undifferentiated: clastic deposits in western Montana, mostly in valleys, and in most places not divided into formations; mostly poorly consolidated gravel, sand, silt, and clay; includes some tuffaceous material and locally lenses of lignite and bentonite; a little hot spring tufa; and in areas not yet mapped in detail, lava may be included. These rocks were in part laid down in lakes but a large part was formed in streams and alluvial fans. These rocks are Tertiary in age and as now mapped may even include some beds of Cretaceous age. Some late Tertiary terrace deposits may be included.

New Mexico

Santa Fe Group (Phanerozoic | Cenozoic | Tertiary Quaternary)

Santa Fe Group, undivided. Basin fill of Rio Grande rift region; middle Pleistocene to uppermost Oligocene

Nevada

Horse Spring Formation (Late Oligocene to Middle Miocene)

HORSE SPRING FORMATION-Tuffaceous sedimentary rocks, southern Nevada

Oregon

Marine sedimentary rocks (Upper Triassic? and Upper and Middle Triassic) (Early Triassic)

Black, green, and gray argillite, mudstone, and shale; graywacke, sandy limestone, tuff, and some coarse volcaniclastic rocks; chert, sandstone comprised of chert clasts, and chert pebble conglomerate; thin-bedded and massive limestone. Locally contains some interbedded lava flows, mostly spilite or keratophyre. In places metamorphosed. Invertebrate marine fauna indicates unit mostly of Late Triassic (Karnian and Norian) age. Includes the Begg and Brisbois Formations of Dickinson and Vigrass (1965; Vester Formation of Brown and Thayer, 1966) and the Rail Cabin Argillite of Dickinson and Vigrass (1965); Fields Creek Formation and Laycock and Murderers Creek Graywackes of Brown and Thayer (1966); Martin Bridge Formation and lower sedimentary series in and near the Wallowa Mountains (Prostka, 1962; Nolf, 1966); and Doyle Creek and Wild Sheep Creek Formations (Vallier, 1977). Probably partly age correlative with rocks of the Applegate Group (Wells and Peck, 1961) of southwestern Oregon

Texas

Allamore Formation (preCambrian-Proterozoic [Grenville])

Allamore Formation

older volcanic rocks of Davis and Barilla Mountains, including Sheep Pasture, Sleeping Lion, Frazier Canyon, Adobe Canyon, and Limpia formations, Gomez Tuff, Star Mountain Rhyolite, and Huelster Formation (Phanerozoic | Cenozoic | Tertiary | Eocene-Late)

older volcanic rocks of Davis and Barilla Mountains, including Sheep Pasture, Sleeping Lion, Frazier Canyon, Adobe Canyon, and Limpia formations, Gomez Tuff, Star Mountain Rhyolite, and Huelster Formation

South Rim Formation from Pine Canyon Caldera (Phanerozoic | Cenozoic | Tertiary | Oligocene)

South Rim Formation from Pine Canyon Caldera

Vermont

Ammonoosuc Volcanics (Ordovician)

Ammonoosuc Volcanics - Soda-rhyolite tuff, breccia, and flows. (Northeastern Vermont).

Volcanic breccia, felsitic tuff, and flows. (Permian-Triassic)

Volcanic breccia, felsitic tuff, and flows.

Washington

Lower upper Eocene marine and nonmarine rocks (Eocene)

Predominantly massive to well-bedded tuffaceous marine siltstone with interbedded arkosic and basaltic sandstone. Includes conglomerate in King County and along north side of Olympic Peninsula. Minor lava flows and breccia in western Lewis County and eastern Grays Harbor County. Coal seams in central Lewis County and north-central Pierce County.

Permian rocks (Permian-Triassic)

Conglomerate, graywacke, siltstone, argillite and interbedded fossiliferous limestone, greenstone, and minor angular conglomerate in northwestern Stevens and Ferry Counties. Impure quartzite, sandstone, graywacke, greenstone, ribbon chert, chert breccia, and limestone in Snohomish County and on San Juan Island. Lower Permian limestone on Black Mountain in northwestern Whatcom County. Middle Permian rocks in northeastern Washington.

Tertiary nonmarine rocks, undivided (Tertiary; mostly Eocene)

Sandstone, shale, conglomerate, agglomerate, and tuff; includes some lava flows. Massive conglomerate, sandstone, siltstone, and ferruginous shale in northwestern Whatcom County.