Annual report of the United States Geological Survey to the Secretary of the Interior . FlO. fi.—Section of left hank of Nehalem Rirer,near SIU). 1, Whitish, tuffaceousradiolarianshale; 2, Fossiliferous dark MIOCENE. 471 On the West Fork of Dairy Creek both sandstones and shales latter are dark within, but weather gray, and when freshly brokenhave a decided odor of petroleum. The best exposure is in sec. 32, 2f., E. 4 W., where a large landslide has occurred, exposing 250 feetof the shale. It is rather massive than fissile, and contains, besidesoccasional casts of mollusk
Annual report of the United States Geological Survey to the Secretary of the Interior . FlO. fi.—Section of left hank of Nehalem Rirer,near SIU). 1, Whitish, tuffaceousradiolarianshale; 2, Fossiliferous dark MIOCENE. 471 On the West Fork of Dairy Creek both sandstones and shales latter are dark within, but weather gray, and when freshly brokenhave a decided odor of petroleum. The best exposure is in sec. 32, 2f., E. 4 W., where a large landslide has occurred, exposing 250 feetof the shale. It is rather massive than fissile, and contains, besidesoccasional casts of mollusks, numerous small fragments of carbonizedvegetal matter and minute bright scales of muscovite. Under themicroscope it is seen to contain some volcanic material, also traces ofradiolaria, and occasional green grains of glauconite. The fossils foundhere, Yoldia impressa Conr., Callista angustifrons, Lucina acutilineataConr., with others not specifically determinable, are referred to theMiocene. The occurrence of bituminous light-colored shales in Oregoncontaining radiolarian and volcanic fragments is of much interest onaccount of their close resemblance to the Monterey shales of the kindness of P
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