GEOLEX

Summary of Citation: Bonner

Publication:
Nelson, W.H. and Dobell, J.P., 1961, Geology of the Bonner
   quadrangle, Montana, IN Contributions to general geology,
   1959: U.S. Geological Survey Bulletin, 1111-F, p. F189-F235

Usage in Publication:
Bonner quartzite*

Modifications:	Geologic Province:	Dominant Lithology:
Named	Northern Rocky Mountain region	Quartzite

Summary:
Named as a formation in Missoula group of Belt series for exposures on both sides of the Blackfoot River just above town of Bonner, secs 14 and 15, T13N, R18W, Missoula Co, MT in Northern Rocky Mountain region. No type locality specifically designated. Widely exposed throughout quad. Parallels many major faults. Is commonly in large-scale folds. Crests of many mountains upheld by this resistant unit. Outcrops rare. Is represented by blocky accumulations of pink feldspathic quartzite. Is predominantly vitreous arkosic quartzite, usually pink, commonly cross-bedded. Quartzite made up of moderately well rounded detrital grains ranging from 1/2 to about 12 mm. Is 70-80 percent quartz, 10-15 percent microcline, 5-10 percent argillite. Accessory minerals are muscovite, hematite, zircon, rutile, leucoxene, garnet, and tourmaline. Minor amount of interbedded red argillite. Some silty green layers. Is about 1,500 ft thick on north side of Mount Sentinel. Is about 800 ft thick 1 mi east of Bonner. Overlies Miller Peak argillite (revised) of Missoula group; underlies McNamara argillite (revised, redefined) of Missoula. Was formerly called middle member of McNamara. Contact with revised McNamara is gradational as argillite and siltstone are more numerous in upper Bonner. Assigned to the Precambrian. Geologic map, stratigraphic chart.

Summary of Citation: Bonner

Publication:
McGill, G.E. and Sommers, D.A., 1967, Stratigraphy and correlation
   of the Precambrian Belt Supergroup of the southern Lewis and
   Clark Range, Montana: Geological Society of America Bulletin,
   v. 78, no. 3, p. 343-351

Usage in Publication:
Bonner Quartzite

Modifications:	Geologic Province:	Dominant Lithology:
Overview Reference	Northern Rocky Mountain region

Summary:
Name Missoula Group has been applied to all rocks in the Precambrian Belt Supergroup above the carbonate (Siyeh Formation of Glacier National Park or Helena Formation of Helena area). These same rocks were designated Camp Creek Series by Walcott in 1906, but that name has been little used and is abandoned in favor of Missoula in this report. The Camp Creek section is designated a reference section [but section not described] for the Missoula. The reference section is located along crest of the ridge parallel to and northwest of Camp Creek in secs 22, 28, and 33, T20N, R12W, Lewis and Clark Range, Powell Co, MT in Northern Rocky Mountain region where the following formations of the Missoula are exposed (ascending order): Snowslip, Shepard, and Shields Formations, Bonner Quartzite, McNamara and Garnet Range Formations. Geologic map.

Summary of Citation: Bonner

Publication:
Harrison, J.E., 1972, Precambrian Belt basin of northwestern
   United States; its geometry, sedimentation and copper
   occurrences: Geological Society of America Bulletin, v. 83,
   no. 5, p. 1215-1240

Usage in Publication:
Bonner Quartzite*

Modifications:	Geologic Province:	Dominant Lithology:
Areal limits Overview	Northern Rocky Mountain region

Summary:
Is used in Northern Rocky Mountain region as formation in Missoula Group of Belt Supergroup of Precambrian age. Replaces use of Greenhorn Mountain Quartzite (abandoned) in southern part of Belt basin and use of Lupine Quartzite (abandoned) of the middle part of the Belt basin (at St. Regis in the Alberton and Missoula areas). See figs 4, 5, and 13 for correlation with other formations of the Belt in the U.S. Northern Rocky Mountain region, and of the Purcell Supergroup in Alberta and British Columbia, Canada.

Summary of Citation: Bonner

Publication:
Mudge, M.R., 1972, Pre-Quaternary rocks in the Sun River Canyon
   area, northwestern Montana, IN Geology of the Sun River
   Canyon, area, northwestern Montana: U.S. Geological Survey
   Professional Paper, 663-A, p. A1-A142, (incl. geologic map,
   scale 1:48,000)

Usage in Publication:
Bonner Formation*

Modifications:	Geologic Province:	Dominant Lithology:
Revised Areal limits	Northern Rocky Mountain region

Summary:
Revised in that Bonner Formation of Missoula Group of Belt Supergroup overlies the renamed Mount Shields Formation (formerly called Shields Formation) of Belt. Contact with Mount Shields is sharp, regarded as a disconformity. Contact with overlying McNamara Formation of Belt is also sharp. Is 1,100 ft thick at southwest corner of geologic map. Mapped at west edge in Lewis and Clark Co, MT in the Northern Rocky Mountain region. Replaces former use of lower member of Ahorn Quartzite (abandoned) of Deiss (1943) and Ahorn Sandstone of Mudge (1966). Correlation chart. Precambrian age.

Summary of Citation: Bonner

Publication:
Wells, J.D., 1974, Geologic map of the Alberton quadrangle,
   Missoula, Sanders, and Mineral Counties, Montana: U.S.
   Geological Survey Geologic Quadrangle Map, GQ-1157, 1 sheet,
   scale 1:62,500

Usage in Publication:
Bonner Quartzite*

Modifications:	Geologic Province:	Dominant Lithology:
Age modified	Northern Rocky Mountain region

Summary:
Is one of eleven formations of the Belt Supergroup mapped in the report area. Age changed from Precambrian to Precambrian Y, the age term used for rocks that range in age from 1,600 to 800 m.y. old. About 3,000 ft thick. Lower contact with Miller Peak Formation of Belt is gradational. Upper contact with McNamara Formation sharp and conformable. Mapped at south-central edge of quad in Missoula Co, MT in Northern Rocky Mountain region.

Summary of Citation: Bonner

Publication:
Hobbs, S.W., 1980, The Lawson Creek Formation of Middle Proterozoic
   age in east-central Idaho, IN Contributions to stratigraphy:
   U.S. Geological Survey Bulletin, 1482-E, p. E3-E9

Usage in Publication:
Bonner Quartzite*

Modifications:	Geologic Province:	Dominant Lithology:
Paleomagnetics Age modified	Northern Rocky Mountain region

Summary:
Polarity zonation and direction indicate that the upper Swauger Quartzite and Lawson Creek Formation of ID correlate with the upper Mount Shields Formation, Bonner Quartzite, and lower McNamara Formation of MT, all in Northern Rocky Mountain region. Bonner assigned to the Proterozoic Y (previously Precambrian Y), the age designation for rocks 1,600 to 900 m.y. old.