Upper Cretaceous marine rocks, unit 2 (Klamath Mountains)

Upper Cretaceous sandstone, shale, and conglomerate
State California
Name Upper Cretaceous marine rocks, unit 2 (Klamath Mountains)
Geologic age late Early to Late Cretaceous
Lithologic constituents
Major
Sedimentary > Clastic > Sandstone (Bed)Ranges from fine- to coarse-grained and pebbly; massive to well-bedded; includes graded turbidites
Sedimentary > Clastic > Mudstone (Bed)Most abundant in upper part of unit
Minor
Sedimentary > Clastic > Conglomerate (Bed)
Sedimentary > Clastic > Siltstone (Bed)
Incidental
Sedimentary > Clastic > Sedimentary-breccia (Bed)Present locally at base of unit
Sedimentary > Coal > Bituminous (Bed)
Comments Northernmost California on east side of Klamath Mountains. Consists primarily of sandstone, siltstone, mudstone, and minor conglomerate. Depositional environments range from nonmarine and shallow-marine in lower part to deep-marine (turbidite facies) in upper part
Stratigraphic units Hornbrook Fm.
References

Jennings, C.W., Strand, R.G., Rogers, T.H., Boylan, R.T., Moar, R.R., and Switzer, R.A., 1977, Geologic Map of California: California Division of Mines and Geology, Geologic Data Map 2, scale 1:750,000.

Jennings, C.W., 1985, An explanatory text to accompany the 1:750,000 scale fault and geologic maps of California: California Division of Mines and Geology, Bulletin 201, 197 p.

Strand, R.G., 1964, Geologic map of California, Olaf P. Jenkins edition, Weed sheet, scale 1:250,000.

Wagner, D.L., and Saucedo, G.J., 1987, Geologic map of the Weed quadrangle, California: California Division of Mines and Geology, Regional Geologic Map Series, Map 4A, scale 1:250,000.

Nilsen, T.H., 1993, Stratigraphy of the Cretaceous Hornbrook Formation, southern Oregon and northern California: U.S. Geological Survey Professional Paper 1521, 89 p.

https://pubs.er.usgs.gov/publication/pp1521

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Counties Siskiyou