4 mile SW Marathon section, collection 1: Tremadoc, Texas
collected by Wilson 1951-

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Agnostida - Agnostidae
Geragnostus rudis (Salter 1864)
Agnostida - Diplagnostidae
Litagnostus sp. Rasetti 1944
Trilobita - Olenida - Olenidae
Leptoplastus sp. Angelin 1854
see common names

Geography
Country:United States State/province:Texas County:Brewster
Coordinates: 30.2° North, 103.3° West (view map)
Paleocoordinates:16.4° South, 92.2° West
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
10 m.y. bin: Cambrian-Ordovician
*Period:Ordovician *Epoch:Tremadoc
Key time interval: Tremadoc
Age range of interval: 485 - 477.7 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:Dagger Flat Member:Roberts Ranch
Local section:4 miles SW Marathon Local bed:175 ft
Local order:bottom to top
Lithology and environment
Primary lithology:fine,gray sandy "limestone"
Secondary lithology:gray,green "shale"
Lithology description: Limestone, sandy, fine-grained, finely cross-bedded, flaggy, dark gray; weathers moderate yellowish brown and interbedded with much greenish gray shale. Lower 10 feet forms ridge traceable for several hundred yards. Collection in base of these beds.
Environment:basinal (carbonate)
Geology comments: "dark gray ls and green to dark sh. deep water? (basinal) BA6."
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection methods:field collection
Reason for describing collection:taxonomic analysis
Collectors:Wilson Collection dates:1951-52
Taxonomic list comments:This collection record was created to encompass all of the collections made from Dagger Flat and described in Wilson 1954; this record now represents the first collection made from this section and new records have been created for the other collections from the section.
Metadata
Database number:279
Authorizer:J. Sepkoski Enterer:M. Sommers
Modifier:M. Hopkins Research group:marine invertebrate
Created:1998-11-20 10:07:18 Last modified:2021-11-26 15:35:04
Access level:the public Released:1998-11-20 10:07:18
Creative Commons license:CC BY
Reference information

Primary reference:
26476. J.L. Wilson. 1954. Late Cambrian and Early Ordovician Trilobites from the Marathon Uplift, Texas. Journal of Paleontology 28(3):249-285 [P. Wagner/P. Wagner]