Where: Clayton County, Iowa (43.0° N, 91.2° W: paleocoordinates 20.2° S, 63.2° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Glenwood, Platteville, Decorah Formation, Blackriveran to Blackriveran (457.3 - 449.6 Ma)

• formation-level stratigraphic resolution

Environment/lithology: shale and limestone

Size class: microfossils

Collection methods: chemical,

Primary reference: W. F. Rice and E. P. Hedblom. 1987. Brachiopods and trilobites of the Sardeson Beds in the Twin Cities. Middle and Late Ordovician lithostratigraphy and biostratigraphy of the Upper Mississippi Valley: Minnesota Geological Survey Report of Investigations 35 131-135 [S. Holland/T. Hanson/T. Hanson]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 23300: authorized by Steven Holland, entered by Tori Hanson on 11.07.2002

Creative Commons license: CC BY (attribution)