Reno Mbr, Franconia Fm - Bed 3, Rileys Coulee section (Cambrian of the United States)

Where: Wabasha County, Minnesota (44.4° N, 91.2° W: paleocoordinates 20.4° S, 79.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Reno Member (Franconia Formation), Franconian (497.0 - 485.4 Ma)

• LITHOSTRATIGRAPHY: Reno Mbr of the Franconia Fm (following Berg 1953, 1954). STRATIGRAPHIC RELATIONS: From the Reno Mbr, the upper member of the Franconia Fm, which is underlain by the Tomah Mbr. The Franconia Fm is overlain by the Black Earth Mbr of the St Lawrence Fm. AGE: From the base of the Prosaukia subzone, Ptychaspis-Prosaukia Zone (Howell et al. 1944) of the Middle Croixan. STRATIGRAPHIC POSITION: Unit 3, 3 ft thick, in the upper portion of a 40+ ft thick section

• bed-level stratigraphic resolution

Environment/lithology: offshore; lithified, bioturbated, fine-grained, glauconitic sandstone

• ENVIRONMENT: From text: "...shallow marine water on a slightly irregular shelf...deposition in quiet water, protected from more aggitated environments", assigned to a siliciclastic - offshore environment. TECTONIC SETTING: Tectonic data not reported in text. SEQUENCE STRATIGRAPHY: Sequence stratigraphic data not reported.
• GENERAL LITHOLOGY: Fine-grained, cross-laminated, highly glauconitic sandstone alternating with massive, mottled beds of glacuonitic wormstone. LITHIFICATION: Assumed to be lithified, based on age and observation of figured specimens.

Size class: macrofossils

Preservation: cast, mold/impression

Reposited in the USNM

Collection methods: bulk, quarrying,

• COLLECTOR: R.E Grant. REPOSITORY: USNM

Primary reference: R. E. Grant. 1962. Trilobite distribution, upper Franconia Formation (Upper Cambrian), southeastern Minnestoa. Journal of Paleontology 36(5):965-998 [A. Miller/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 62119: authorized by Austin Hendy, entered by Austin Hendy on 12.07.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• COMPLETENESS: Limited to trilobita, exhaustive for trilobites, however. NOMENCLATURE: Authoritative publication, but somewhat historic nomenclature.
Show authors, comments, and common names
Trilobita
 Olenida - Idahoiidae
Wilbernia pero
Wilbernia pero Walcott 1890 trilobite
 Asaphida - Ptychaspididae
Ptychaspis striata, Ptychaspis miniscaensis
Ptychaspis miniscaensis Owen 1852 trilobite
 Asaphida - Dikelocephalidae
Prosaukia misa
Prosaukia misa Owen 1852 trilobite
 Ptychopariida - Elviniidae
Chariocephalus whitfieldi
Chariocephalus whitfieldi Hall 1863 trilobite
  - Ellipsocephaloididae
Ellipsocephaloides gracilis