Reno Mbr, Franconia Fm - Bed 6, Rileys Coulee section: Franconian, Minnesota
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Trilobita
- Asaphida
- Dikelocephalidae
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Prosaukia misa
(Owen 1852)
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Trilobita
- Asaphida
- Ptychaspididae
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Ptychaspis striata
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Ptychaspis miniscaensis
(Owen 1852)
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Trilobita
- Ptychopariida
- Elviniidae
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Chariocephalus whitfieldi
Hall 1863
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Trilobita
- Olenida
- Idahoiidae
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? Saratogia hamula
(Owen 1852)
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| see common names | |||||||
Geography
| Country: | United States | State/province: | Minnesota | County: | Wabasha |
| Coordinates: | 44.4° North, 91.2° West (view map) | ||||
| Paleocoordinates: | 20.4° South, 79.8° West | ||||
| Basis of coordinate: | based on nearby landmark | ||||
| Geographic resolution: | outcrop |
Time
| Period: | Cambrian | Epoch: | Furongian |
| 10 m.y. bin: | Cambrian 5 | ||
| Key time interval: | Franconian | ||
| Age range of interval: | 497 - 485.4 m.y. ago |
Stratigraphy
| Formation: | Franconia | Member: | Reno | ||
| Local section: | Rileys Coulee | Local bed: | 24 ft | ||
| Local order: | bottom to top | ||||
| Stratigraphic resolution: | bed | ||||
| Stratigraphy comments: 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 6, 2 ft thick, in the upper portion of a 40+ ft thick section | |||||
Lithology and environment
| Primary lithology: | bioturbation,fine,glauconitic lithified sandstone |
| Includes fossils? | Y |
| Lithology description: 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. | |
| Environment: | offshore |
| Geology comments: 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. | |
Taphonomy
| Modes of preservation: | body,cast,mold/impression |
| Size of fossils: | macrofossils |
| Preservation of anatomical detail: | medium |
| Temporal resolution: | time-averaged |
| Spatial resolution: | parautochthonous |
Collection methods and comments
| Collection methods: | bulk,selective quarrying,field collection |
| Reason for describing collection: | taxonomic analysis |
| Museum repositories: | USNM |
| Collection method comments: COLLECTOR: R.E Grant. REPOSITORY: USNM | |
| Taxonomic list comments:COMPLETENESS: Limited to trilobita, exhaustive for trilobites, however. NOMENCLATURE: Authoritative publication, but somewhat historic nomenclature. | |
Metadata
| Database number: | 62122 | ||
| Authorizer: | A. Hendy | Enterer: | A. Hendy | Research group: | marine invertebrate |
| Created: | 2006-07-12 17:54:45 | Last modified: | 2013-11-25 13:37:23 |
| Access level: | the public | Released: | 2006-07-12 17:54:44 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 17950. | R. E. Grant. 1962. Trilobite distribution, upper Franconia Formation (Upper Cambrian), southeastern Minnestoa. Journal of Paleontology 36(5):965-998 [A. Miller/A. Hendy] |