Pg. 6-26. Hector Formation. Consists of (descending): tan-grayish brown tuffaceous sandstone, orangish brown-reddish brown tuffaceous sandstone, brown-brownish gray conglomeratic sandstone, "marker tuff bed," tuffaceous sandstone with coarse conglomeratic sandstone with tuff bed (K-Ar age of 21.0 +/-5 Ma), and coarsely conglomeratic northern facies. Thickness about 1,600 feet (490 m). Unconformably overlies andesitic lahar and agglomerate; unconformably underlies Pleistocene alluvium. Fossils (the Black Butte and Logan Mine local mammal faunas). Age is early Miocene (late Arikareean and early Hemingfordian NALMA).
Type area: 4 mi north of Hector siding of the Atchison, Topeka and Sante Fe RR, in sec. 13, 22, and 26, T. 9 N., R. 5 E., Cady Mountains, San Bernardino Co., southern CA.
Source: Publication.
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