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

Geologic units in Butte county, Idaho

[Additional scientific data in this geographic area]

Sand; Holocene dunes; Snake River Plain (Holocene) at surface, covers 0.9 % of this area

Recent active sand dunes and eolian deposits.

Lithology: dune sand; eolian

Limestone, dolostone, sandstone, siltstone, and chert; Lower Permian to Lower Pennsylvanian marine continental-shelf deposits; east-central Idaho (Early Permian to Early Pennsylvanian) at surface, covers 6 % of this area

Lower Permian to Lower Pennsylvanian (Carboniferous) shallow-water detritus.

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

Clastic debris; Quaternary colluvium, fanglomerate, talus, and glacial deposits; upland-valley margins (Quaternary) at surface, covers 4 % of this area

Quaternary colluvium, fanglomerate, and talus plus some glacial debris in upland valleys.

Lithology: alluvium; glacial drift; colluvium

Rhyolitic tuffs, ignimbrites, and flows, basaltic flows, conglomerate and marlstone; Pliocene to Miocene volcano-sedimentary deposits; eastern Snake River Plain and southeastern Idaho (Pliocene-Miocene) at surface, covers 0.4 % of this area

Pliocene volcanic units, generally air-fall or pyroclastic in origin; grade into (Tpd).

Lithology: rhyolite; tuff; ignimbrite; tholeiite; conglomerate; marlstone

Quartzite, siltite, argillite, and mica schist; Middle Proterozoic Lemhi Group; southern Belt province (Middle Proterozoic) at surface, covers < 0.1 % of this area

Intermediate Precambrian sediments, feldspathic quartzite and siltstone of southern Idaho.

Lithology: quartzite; siltstone; meta-argillite; exhalite; mica schist; lamprophyre

Chert, shale, phosphorite, and carbonates; Permian restricted marine epicontinental-basin deposits; southeastern Idaho (Permian) at surface, covers < 0.1 % of this area

Permian phosphatic sandstone, mudstone and chert of east-central Idaho.

Lithology: chert; shale; phosphorite; dolostone (dolomite); arenite; limestone

Gravel, sand, and silt; Quaternary; alluvium (Quaternary) at surface, covers 15 % of this area

Quaternary alluvium; may contain some glacial deposits and colluvium in uplands

Lithology: alluvium; alluvial terrace; floodplain; alluvial fan; colluvium

Trachyandesite, latite, trachybasalt flows, dikes, and volcaniclastic debris; Eocene intermediate volcanics; central Idaho, southern Challis volcanic field (Eocene) at surface, covers 1 % of this area

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

Lithology: trachyandesite; latite; trachybasalt; dacite; trachyte; lava flow; volcanic breccia (agglomerate)

Basalt, gravel, and pumice; Late Pleistocene basaltic volcanics and interlayered sedimetnsof subunit 3b; Snake River Plain (Late Pleistocene) at surface, covers 1 % of this area

Upper Pleistocene Snake Plain basaltic lava flows, unit 3.

Lithology: tholeiite; lava flow; gravel; pumice

Limestone, shale, siltstone, chert, and conglomerate; Mississippian western turbiditic flysch to eastern shallow-water carbonates; east-central Idaho (Mississippian) at surface, covers 10 % of this area

Mississippian shallow-water carbonate-to-clastic sequence of east-central Idaho.

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

Rhyolitic domes, flows, pyroclastic debris, and basalt flows; Early Pleistocene subvolcanic to volcanic features; eastern Snake River Plain (Early Pleistocene) at surface, covers 0.3 % of this area

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

Lithology: alkali rhyolite; tholeiite; lava flow; bimodal suite; volcanic breccia (agglomerate)

Monzogranite, granodiorite, syenite, monzodiorite, monzonite, and diorite; Eocene phaneritic to porphyro-aphanitic intrusions (subunits are Teif and Teii); northern Idaho to central Idaho (Eocene) at surface, covers < 0.1 % of this area

Eocene intrusions including large granitic plutons and dike swarms of central Idaho

Lithology: granite; quartz monzodiorite; granodiorite

Dacite to rhyolite (or rhodacite) ignimbrites; Eocene rhyodacitic cauldron complex; east-central Idaho, central Challis volcanic field (Eocene) at surface, covers 3 % of this area

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

Lithology: rhyodacite; ignimbrite; lava flow; rhyolite; quartz latite; dacite; andesite; basalt; volcanic breccia (agglomerate); mixed clastic/volcanic

Dolostone, arenite, conglomerate, and chert; Silurian to Middle Ordovician marine outer continental-shelf deposits; east-central Idaho (Silurian to Middle Ordovician) at surface, covers 3 % of this area

Silurian to Middle Ordovician marine carbonate-to-clastic strata of east-central Idaho.

Lithology: dolostone (dolomite); arenite; conglomerate; chert

Basalt and gravel; Late Pleistocene basalt flows and interlayered gravel of subunit 2b; Snake River Plain (Late Pleistocene) at surface, covers 24 % of this area

Upper Pleistocene Snake Plain basaltic lava flows, unit 2.

Lithology: tholeiite; lava flow; gravel

Dolostone, limestone, sandstone, shale, and conglomerate; Devonian marine continental-shelf deposits; east-central and southeastern Idaho (Devonian) at surface, covers 3 % of this area

Devonian bedded dolomite and limestone interval of eastern and southern Idaho.

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

Shale, conglomerate, sandstone, siltstone, limestone, and chert; Mississippian turbidite flysch from a western source; central Idaho (Mississippian) at surface, covers 0.4 % of this area

Mississippian thrusted, shallow-to-deep marine detrital units of central Idaho.

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

Dolostone, limestone, arenite, and chert: Devonian to Ordovician marine outer continental-shelf deposits; east-central Idaho (Devonian to Ordovician) at surface, covers < 0.1 % of this area

Devonian to Ordovician marine calcareous sediments north of the Snake Plain.

Lithology: dolostone (dolomite); limestone; arenite; chert

Glacial debris; Late Pleistocene glacial till, outwash, and alluvium of continental glaciers; northern Idaho (Late Pleistocene ) at surface, covers 0.1 % of this area

Pleistocene till, moraines and similar unsorted glacial debris.

Lithology: till; outwash; alluvium

Quartzite, argillite, carbonate, meta-conglomerate, siltite, intermediate volcanic rock; Late Proterozoic rifted continental margin; southeastern Idaho (Late Proterozoic) at surface, covers 0.6 % of this area

Younger Precambrian detrital units of central and southeastern Idaho; subdivisions are (Z2s and Z1s).

Lithology: quartzite; argillite; carbonate; conglomerate; siltstone; intermediate volcanic rock

Gravel, sand, and silt; Quaternary basin-filling alluvium; Snake River Plain, Basin and Range provinces (Quaternary) at surface, covers 13 % of this area

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

Lithology: alluvium; alluvial fan; alluvial terrace

Basalt, clay, and gravel; Late Pleistocene basalt flows with interlayered alluvial and lacustrine sediments; Snake River Plain and vicinity (subunits are Qpu1b, Qpu2b, Qpu3b, and Qpu4b) (Late Pleistocene) at surface, covers 2 % of this area

Upper Pleistocene Snake Plain lava flows; local stratigraphic position shown by (Qpu4b, Qpu3b, Qpu2b, Qpu1b).

Lithology: tholeiite; lava flow; clay or mud; gravel

Glacial debris; Late Pleistocene till, outwash, and alluvium of valley glaciers; high mountain valleys (Late Pleistocene ) at surface, covers 0.2 % of this area

Pleistocene upland valley deposits; commonly derived from alpine glaciation.

Lithology: till; outwash; alluvium

Basalt, pumice; Holocene basaltic lava flows and cinder cones; Snake River Plain and vicinity (Holocene) at surface, covers 9 % of this area

Recent, relatively unweathered Snake Plain basalt flows and cinder cones.

Lithology: tholeiite; lava flow; pumice

Quartzite, meta-conglomerate, dolostone, argillite; Middle Proterozoic Swauger quartzite; southern Belt province (Middle Proterozoic) at surface, covers < 0.1 % of this area

Intermediate Precambrian sediments, red-tinted quartzite with minor conglomeratic and dolomitic lenses of southern Idaho

Lithology: quartzite; meta-conglomerate; dolostone (dolomite); meta-argillite

Tuffaceous shale, sandstone, conglomerate, and lignite; Eocene to Pliocene alluvial and lacustrine deposits; central and southern Idaho (Tertiary) at surface, covers 1 % of this area

Tertiary continental sediments; predominantly Upper Tertiary in age; subdivisions are:(Tpd, Tmd, and Ted).

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

Basalt flows, pumice, and tuff; Early Pleistocene to Pliocene basaltic volcanics; Snake River Plain (Early Pleistocene) at surface, covers 2 % of this area

Lower Pleistocene to Pliocene basalts with associated tuffs and volcanic detritus.

Lithology: tholeiite; lava flow; pumice; tuff

Basalt flows, pyroclastic debris, clastic sediments, and diatomite; Pliocene basaltic volcanics and clastic sediments; Snake River Plain and vicinity (Pliocene) at surface, covers 0.2 % of this area

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

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

Surficial sediments; Quaternary alluvial, lacustrine, eolian, and glacial-outwash deposits, undivided; Snake River Plain, and Basin-and-Range provinces (Quaternary) at surface, covers 0.2 % of this area

Quaternary surficial cover; Snake Plain stream, lake, wind and glacial-flood mantle.

Lithology: loess; colluvium