Butte Creek, Malheur Co., Oregon, USA

Age: Pleistocene (0 - 2.588 Ma)

Description: Alluvium; unconsolidated rocks; mixed grained sediments; fluvial; silt to gravel grains

Lithology: Major:: {mixed fluvial sediment} Minor:: {mixed alluvial fan sediment}; Minor:: {mixed playa sediment}; Minor:: {colluvium}; Minor:: {loess}

Reference: R.L. Smith, W.P. Roe (compilers). Oregon Geologic Data Compilation, release 6. State of Oregon Department of Geology and Mineral Industries. [20]

Age: Neogene (2.588 - 23.03 Ma)

Stratigraphic Name: Columbia River Basalt

Comments: Columbia Plateau

Lithology: Flood basalt(s); mafic volcanic rocks; basalt

Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154]

Age: Miocene (5.333 - 23.03 Ma)

Stratigraphic Name: Deer Butte Formation; Juntura Formation; Columbia River Basalt Group; Danforth Formation; Leslie Gulch Ash-Flow Tuff

Description: Poorly to moderately consolidated, bedded silicic ash and pumicite, diatomite, tuffaceous sedimentary rocks, minor mudflow deposits, and some coarse epiclastic deposits. Vitroclastic material in some beds diagenetically altered to zeolites, secondary silica minerals, and clay minerals. In eastern Blue Mountains province vertebrate fossils indicate unit is mostly of late Miocene (Clarendonian) age, but may also include some rocks of middle Miocene (Barstovian) age. In High Lava Plains and northern Owyhee Upland provinces, vertebrate fossils indicate unit is partly late Miocene (Clarendonian), but probably is mostly middle Miocene (Barstovian) in age. Interfingers and grades laterally into unit Tmb. Includes lake and stream sediments and tuffaceous lake and stream deposits of Prostka (1962, 1967), Deer Butte Formation of Corcoran and others (1962) and Kittleman and others (1967), Juntura Formation of Shotwell and others (1963), some rocks originally assigned to the lower part of the (now obsolete) Danforth Formation of Piper and others (1939), and interbeds in upper part of Columbia River Basalt Group in northern Wallowa County

Comments: Includes Leslie Gulch Ash-Flow Tuff and Tuff of Spring Creek (OR173)

Lithology: Major:{rhyolite,diatomite,siltstone mudstone}, Minor:{conglomerate}

Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. [133]