ammonites
Sardeson Collection, Quimbys Mill Formation, Illinois and Iowa (Ordovician of the United States)

Where: Illinois, Iowa (42.0° N, 90.5° W: paleocoordinates 21.3° S, 63.6° W)

• coordinate estimated from map

• basin-level geographic resolution

When: Quimbys Mill Formation, Blackriveran (460.9 - 449.5 Ma)

• formation-level stratigraphic resolution

Environment/lithology: limestone

• Environmental call by T. Hanson.
• "12 to 14 feet thick . . . medium to thin beds of limestone and dolomite separated by thin shale laminae." Lithology from  O. L. Karklins. 1987. Bryozoa from Rocklandian (Middle Ordovician) rocks of the Upper Mississippi Valley region. Middle and Late Ordovician lithostratigraphy and biostratigraphy of the Upper Mississippi Valley: Minnesota Geological Survey Report of Investigations 35 :173-176, R.E. Sloan, ed.

Size class: macrofossils

Primary reference: J. A. Catalani. 1987. Biostratigraphy of the Middle and Late Ordovician cephalopods of the Upper Mississippi Valley area. Middle and Late Ordovician lithostratigraphy and biostratigraphy of the Upper Mississippi Valley: Minnesota Geological Survey Report of Investigations 35 187-189 [S. Holland/T. Hanson/T. Hanson] more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 23794: authorized by Steven Holland, entered by Tori Hanson on 21.07.2002