USGS Visual Identifier

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Geologic Unit: Banbury

Publication:
Stearns, H.T., 1936, Origin of the large springs and their 
   alcoves along the Snake River in southern Idaho: Journal of 
   Geology, v. 44, no. 4, p. 429-450.
Usage in Publication:
Banbury volcanics*

Modifications: Geologic Province: Dominant Lithology:
 Named
 Snake River basin
 Basalt
 Tuff

Summary:
Consists of about 360 feet of massive, dark-brown, weathered basalt flows and coarse and fine tuff beds. Overlies Raft lake beds (new); underlies Hagerman lake beds (new). Age is late Pliocene.
Type locality: exposures near Banbury Hot Springs, in sec. 33, T. 8 S., R. 14 E., Twin Falls Co., ID, Snake River basin. Named from Banbury Hot Springs.
Source: Modified from GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Stearns, H.T., Crandall, L., and Steward, W.G., 1938, Geology 
   and ground-water resources of the Snake River Plain in 
   southeastern Idaho: U.S. Geological Survey Water-Supply Paper, 
   774, 268 p.
Usage in Publication:
Banbury volcanics*

Modifications: Geologic Province: Dominant Lithology:
 Overview
 Snake River basin
 

Summary:
Name established as being derived from Banbury Hot Springs, Twin Falls County, Idaho. Is recognized downstream (westerly), along Snake River for 63 miles, from just west of Perrine Ranch, in sec. 28, T. 9 S., R. 17 E., Jerome County, Idaho, to area between Bliss and King Hill, Gooding and Elmore Counties, Idaho; also recognized along Salmon Falls Creek, Twin Falls County, Idaho. [All exposures in Snake River basin.] Consists of a series of even-bedded, massive basalt flows over 300 feet thick, as well as tuffs. Basalt weathers to dark brown, often with greenish cast. Volcanics probably originated from vent located at Riverside Ferry, in secs. 20 and 29, T. 8 S., R. 14 E., Gooding County; vent probably formed beneath a lake. Overlies Raft lake beds; underlies Hagerman lake beds. Unit is interbedded with overlying lake beds, which contain late Pliocene fossils, thus age of Banbury is late Pliocene. Report includes stratigraphic chart, geologic maps.
Source: Modified from GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Malde, H.E., and Powers, H.A., 1962, Upper Cenozoic stratigraphy 
   of western Snake River Plain, Idaho: Geological Society of 
   America Bulletin, v. 73, no. 10, p. 1197-1220.
Usage in Publication:
Banbury Basalt*

Modifications: Geologic Province: Dominant Lithology:
 Revised
 Overview
 Snake River basin
 

Summary:
Assigned as second from base of seven formations of Idaho Group (rank raised). Unconformably underlies Chalk Hills Formation (new); unconformably overlies Poison Ceek Formation, both of Idaho Group. At type, Banbury unconformably overlies Idavada Volcanics (new). Widespread unit recognized over 60 mi downstream from Twin Falls, ID along Snake River as well as on uplands north and south of river, in various counties of southwest ID, Snake River basin. Middle Pliocene age based on fossil mammals and mollusks and stratigraphic position.
Source: GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Coats, R.R., 1964, Geology of the Jarbidge quadrangle, Nevada-Idaho, 
   IN Contributions to general geology, 1961: U.S. Geological 
   Survey Bulletin, 1141-M, p. M1-M24.
Usage in Publication:
Banbury formation*

Modifications: Geologic Province: Dominant Lithology:
 Areal limits
 Redescribed
 Snake River basin
 Great Basin province
 Basalt
 Gravel
 Tuff

Summary:
Extended from Owyhee Co, ID, Snake River basin into northern Elko Co, NV, Great Basin province. Outcrops in northwest corner of quad. Redescribed because of large quantity of interbedded gravels and because of small amounts of rhyolitic tuff (less than 20 ft) immediately below basalt. Basalt forms a lens which thickens gradually northward; gravel beneath basalt thickens rapidly northward; gravel above basalt is thickest near southern margin of basalt flows. Thickness of basalt ranges from 105 ft thinning southward to 4 ft. Thickness of gravel is 600 ft in north end of quad thinning southward to 200 ft. Overlies Cougar Point welded tuff (new); underlies Pleistocene deposits. Geologic map. Assigned middle Pliocene age.
Source: GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Axelrod, D.I., 1964, The Miocene Trapper Creek flora of southern 
   Idaho: University of California Publications in Geological 
   Sciences Bulletin, v. 51, 148 p.
Usage in Publication:
Banbury formation

Modifications: Geologic Province: Dominant Lithology:
 Areal limits
 Redescribed
 Great Basin province
 Basalt
 Sandstone
 Conglomerate
 Siltstone
 Ash

Summary:
Extended into Goose Creek basin area, Cassia Co, ID, Great Basin province where unit is about 300 feet thick on west side of Cassia Mountains. Redescribed from basalt to formation to reflect inclusion of sedimentary rocks within unit. [Rank term basalt used on Table 1]. In study area, Banbury consists of basalt flows and associated sedimentary rocks which include tuffaceous (basaltic) sandstone and pebble conglomerate, white to gray siltstone, diatomite and beds of siliceous volcanic ash. Unconformably overlies Cougar Point formation (redescribed and revised) of Idavada volcanics [rank raised though "group" not added to name]; underlies a basalt flow that may be part of Banbury or Glenns Ferry formation. Stratigraphic charts. Assigned middle Pliocene age.
Source: GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Armstrong, R.L., Leeman, W.P., and Malde, H.E., 1975, K-Ar 
   dating, Quaternary and Neogene volcanic rocks of the Snake 
   River Plain, Idaho: American Journal of Science, v. 275, no. 
   3, p. 225-251.
Usage in Publication:
Banbury Basalt*

Modifications: Geologic Province: Dominant Lithology:
 Isotopic dating
 Snake River basin
 

Summary:
Occurs within southwest ID, Snake River basin. Is second unit from base of Idaho Group. At its type locality (on Snake River near mouth of Salmon Falls Creek) K-Ar dates on Banbury are 4.4 +/-0.6 and 4.9 +/-0.6 m.y. At its type, Banbury overlies Idavada Volcanics and underlies Glenns Ferry Formation (age is 4.4-6.2 m.y.) of Idaho Group. Northwest of its type, near Murphy, Owyhee Co, ID, Banbury underlies Chalk Hills Formation (dated as at least 8.4 m.y.) of Idaho Group. Thus type Banbury is approximately the same age as parts of Glenns Ferry Formation that occurs to north and west but is distinctly younger than the Banbury that underlies Chalk Hills. In Mount Bennett Hills, Banbury is dated a very imprecise 13.5 +/-1.5 m.y. Dates at other localities range to as young as 3 m.y. Isotopic dates reported by E. H. McKee (written comm., 1971) in Owyhee-Jarbidge region range from 8.0-10.6 m.y. (with older dates being preferred). Thus, it is concluded that name Banbury has been used to designate basalts of several ages and may span most of Idaho Group and thus it does not represent a formation of limited stratigraphic position nor a formation of limited range in age. Map showing sample localities; schematic stratigraphic-chronologic diagram for Snake River Plain across ID; table of K-Ar dates.
Source: GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Coats, R.R., 1985, The Big Island Formation, a Miocene formation 
   in northern Elko County, Nevada, and adjacent Idaho, including 
   a consideration of its composition and petrographic character, 
   IN Stratigraphic notes, 1984: U.S. Geological Survey Bulletin, 
   1605-A, p. A7-A13.
Usage in Publication:
Banbury Basalt*

Modifications: Geologic Province: Dominant Lithology:
 Areal limits
 Snake River basin
 

Summary:
A new formation, Big Island Formation, defined to include basalt that was assigned formerly to the Banbury Basalt (Volcanics or Formation) in Elko Co, NV in the Great Basin province. Basalt in Elko Co is between 8.2 +/-0.6 to 10.6 +/-1.0 m.y. old or late Miocene, and thus older than type Banbury in southern ID. Banbury is used in the Snake River basin of ID.
Source: GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Foord, E.E., Luessin, M.J., Hovorka, D.S., Plesha, J.L., Grauch, 
   V.J., Barton, H.N., King, H.D., Capstick, D.O., Mayerle, 
   R.T., Buehler, A.R., and Gabby, P.N., 1987, Mineral resources 
   of the Owyhee Canyon and South Fork Owyhee River Wilderness 
   Study Area, Elko County, Nevada, and Owyhee County, Idaho, 
   IN Mineral resources of wilderness study areas; Owyhee River 
   region, Idaho and Nevada: U.S. Geological Survey Bulletin, 
   1719-F, p. F1-F15, (incl. geologic map, scale 1:50,000)
Usage in Publication:
Banbury Basalt*

Modifications: Geologic Province: Dominant Lithology:
 Not used
   

Summary:
A unit called basalt of Devils Corral is the same as the unit previously mapped as Banbury Basalt. Basalts in the study area are of a different age (10-6 Ma) than the Banbury (7 Ma) and they are different chemically than the Banbury. Unconformably overlies Swisher Mountain Tuff. Mapped occurrence is in southwest Owyhee Co, ID along the south fork of the Owyhee River in the Snake River basin.
Source: GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Jenks, M.D., and Bonnichsen, Bill, 1990, Geologic map of the 
   Bruneau River Wilderness Study Area, Owyhee County, Idaho: 
   U.S. Geological Survey Miscellaneous Field Studies Map, 
   MF-2128, 1 sheet, scale 1:50,000
Usage in Publication:
Banbury Basalt

Modifications: Geologic Province: Dominant Lithology:
 Not used
   

Summary:
Not used in study area in northeast Owyhee Co, ID, Snake River basin. In northeast and east parts of sheet 1 and in northern part of sheet 1 of mapped area, basalts here assigned to units informally referred to as basalt of Winter Camp Butte and basalt at Hot Creek were mapped by Malde and others (1963) as both basalt within Glenns Ferry Formation and Banbury in northeast and east parts, sheet 1 and as both basalt within Chalk Hills Formation and Banbury in northern part, sheet 1. Because of this confusion and lack of radiometric age dates, these basalts are here mapped separately as informal units and are not assigned to previously established stratigraphic units. Source of basalt of Winter Camp Butte is shield volcano located in sec 22, T9S, R8E.
Source: GNU records (USGS DDS-6; Denver GNULEX).