Two Medicine Formation

Geology

Group: Montana

Members: unnamed (34), Lower (9), Middle (2), Upper (33)

Lithologies: not reported (41), claystone (2), mudstone (21), siltstone (7), sandstone (7), conglomerate (1), lime mudstone (1), "limestone" (1), "carbonate" (2)

Paleoenvironments: terrestrial indet. (54), fluvial indet. (3), coarse channel fill (1), fine channel fill (2), "channel" (2), "floodplain" (7), crevasse splay (2), lacustrine - large (1), lacustrine - small (2), pond (1), lacustrine indet. (2)

Age range: base of the Judithian to the top of the Campanian or 83.50000 to 72.10000 Ma
Collections

Time interval Ma Country or state Original ID and collection number
Late/Upper Santonian - Early/Lower Campanian85.8 - 70.6USA (Montana) (47101 53055 53056 53057 53058 133330 142497)
Campanian83.6 - 72.1USA (Montana) (13281 13282 22652 22653 22689 22690 22691 22693 22694 26775 36608 36934 45680 45681 45682 50083 53042 53043 53044 53045 53046 53047 53048 53052 53996 53999 54000 55324 55386 59373 61843 62539 62540 62541 64785 69931 70051 90189 100851 142496 142498 142499 150896 150977 184945 196407 219740 219741 220335)
Campanian83.6 - 72.1Canada (Alberta) (53051)
Early/Lower Campanian83.5 - 70.6USA (Montana) (94368 102177 102178 102179 102180 102181 102182 120363)
Judithian83.5 - 70.6USA (Montana) (14453 32133)
Late/Upper Campanian83.5 - 70.6USA (Montana) (22692 52435 68045 138980)
Middle Campanian83.5 - 70.6USA (Montana) (25658 138573 232277)
Middle Campanian - Late/Upper Campanian83.5 - 70.6USA (Montana) (219742 219743 223339 231393)