Chalk Hills Formation

Geology

Group: Idaho

Members: unnamed (7)

Lithologies: not reported (1), siltstone (4), sandstone (1), conglomerate (1), ash (2)

Paleoenvironments: terrestrial indet. (4), lacustrine indet. (3)

Age range: base of the Hemphillian to the top of the Late/Upper Miocene or 10.30000 to 5.33300 Ma
Collections

Time interval Ma Country or state Original ID and collection number
Miocene23.03 - 5.333USA (Idaho) (18942)
Late/Upper Miocene11.608 - 5.333USA (Idaho) (191558 191559)
Hemphillian10.3 - 4.9USA (Idaho) (18926 19765)
early Early Hemphillian - late Early Hemphillian10.3 - 4.9USA (Idaho) (218109 218111)