Group

Geology

Formations: John Day (4)

Lithologies: not reported (1), siltstone (2), conglomerate (2)

Paleoenvironments: terrestrial indet. (4)

Age range: base of the Harrisonian to the top of the Early/Lower Hemingfordian or 23.10000 to 16.30000 Ma
Collections

Time interval Ma Country or state Original ID and collection number
Harrisonian23.1 - 18.5USA (Oregon) (19037)
Early/Lower Hemingfordian18.5 - 16.3USA (Oregon) (167866 170310 170312)