Also known as Locality H 2; Girty, Aug. 18 and 22, 1916

Where: Washington County, Arkansas (36.1° N, 94.2° W: paleocoordinates 8.1° S, 31.4° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Prairie Grove Member (Hale Formation), Morrowan (323.2 - 318.6 Ma)

• The type locality of the Hale formation is Hale Mountain in wester Washington County where it is relatively thick. Recent work has shown that two mappable members, the Cane Hill below and the Prairie Grove member above, can be recognized in Washington County.

•The Cane Hill member is as much as 65 feet in thickness and is composed largely of silt, silty sandstone, and fine-grained sandstone; locally there are beds of fossiliferous crossbedded limestone in the lower part.

•In the Harrison quadrangle, in Carroll and Boone Counties, the Hale formation as mapped by Purdue and Miser (1916) is overlain by the Atoka formation and contains a considerable amount of shale, particularly the lower part, which may either represent the Cane Hill member, or include the Imo formation and upper shale member of the Pitkin limestone, or parts of all three.

•The two members of the Hale formation can be recognized in Washington and Madison Counties, as well as in adjacent parts of Crawford County. In this region the Cane Hill member rests unconformably on the Pitkin limestone, or on the Fayetteville shale where the Pitkin has been cut out by erosion prior to Morrow deposition. The Prarie Grove member is overlain conformmably by the Bloyd shale.

• group of beds-level stratigraphic resolution

Environment/lithology: shallow subtidal; lithified, shelly/skeletal limestone and lithified, fine-grained, medium, calcareous sandstone

Size class: macrofossils

Reposited in the USGS

Primary reference: M. Gordon. 1964. Carboniferous Cephalopods of Arkansas. United States Geological Survey Professional Paper 460:1-322 [J. Alroy/C. Simpson/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 43375: authorized by John Alroy, entered by Carl Simpson on 12.08.2004, edited by Matthew Clapham

Creative Commons license: CC BY (attribution)