John Day Formation
Geology
Members: unnamed (31), Balm Creek (1), Big Basin (4), Haystack Valley (13), Johnson Canyon (4), Kimberly (7), lower Turtle Cove (1), middle (1), Rose Creek (3), Turtle Cove (9)
Lithologies: not reported (20), claystone (5), "shale" (4), siltstone (12), sandstone (19), conglomerate (3), tuff (11)
Paleoenvironments: terrestrial indet. (64), "channel" (1), fluvial-lacustrine indet. (1), lacustrine indet. (8)
Age range: base of the Duchesnean to the top of the Early/Lower Hemingfordian or 40.40000 to 15.97000 Ma
Collections