Decorah Shale Formation

Geology

Group: Galena

Members: unnamed (21)

Lithologies: claystone (1), "shale" (18), "limestone" (8)

Paleoenvironments: marine indet. (4), carbonate indet. (14), deep subtidal shelf (1), coastal indet. (2)

Age range: Mohawkian or 457.30000 to 451.00000 Ma
Collections

Time interval Ma Country or state Original ID and collection number
Mohawkian457.3 - 451.0USA (Minnesota) (167563 167565 167609)
Blackriveran457.3 - 449.6USA (Minnesota) (167592 167610 167628)
Blackriveran - Kirkfieldian457.3 - 449.6USA (Iowa) (89042)
Rocklandian457.3 - 449.6USA (Minnesota, Iowa, Wisconsin, Illinois) (23309 23312 23377)
Rocklandian - Kirkfieldian457.3 - 449.6USA (Minnesota) (23558 23708)
Rocklandian - Shermanian457.3 - 449.6USA (Minnesota) (23123 23124 23148 23174 23277 23290 23394 23402 23550)