Unit 12, Montebello Member, Mahantango Fm., Amity Hall, PA: Givetian, Pennsylvania

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Strophomenata - Strophomenida - Chonetidae
Devonochonetes syrtalis
very abundant
Devonochonetes coronatus (Hall 1857)
very abundant
Rhynchonellata - Rhynchonellida - Trigonirhynchiidae
Camarotoechia congregata (Conrad 1841)
recombined as Cupularostrum congregata
abundant
Rhynchonellata - Tropidoleptidae
Tropidoleptus carinatus (Conrad 1839)
very abundant
Rhynchonellata - Spiriferida - Spinocyrtiidae
Mediospirifer audaculus (Conrad 1842)
prsent
Trilobita - Phacopida - Homalonotidae
Trimerus (Dipleura) dekayi Green 1832
abundant
Crinoidea
Crinoidea indet. Miller 1821
abundant (columnals)
see common names

Geography
Country:United States State/province:Pennsylvania
Coordinates: 40.4° North, 77.0° West (view map)
Paleocoordinates:39.2° South, 25.4° West
Geographic resolution:small collection
Time
Period:Devonian Epoch:Middle Devonian
Stage:Givetian 10 m.y. bin:Devonian 3
*Local age/stage:Erian
Key time interval:Givetian
Age range of interval:387.70000 - 382.70000 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Geological group:Hamilton Formation:Mahantango Member:Montebello
Local section:Amity Hall Local bed:unit 12
Local order:top to bottom
Stratigraphic resolution:group of beds
Lithology and environment
Primary lithology:"cross stratification",gray sandy siltstone
Secondary lithology: "shale"
Includes fossils?Y
Includes fossils?Y
Lithology description: interbedded shale and siltstone, siltstone and very fine grained sandstone, dark greenish gray, in cross beds and lenticular beds commonly 2-4 inches, but up to 2 ft. thick, shale, snady micaceous, forms less than 10% of lower half of unit, 80% of upper half
Environment:marine indet. Tectonic setting:foreland basin
Taphonomy
Collection methods and comments
Collection methods:surface (in situ),field collection
Reason for describing collection:paleoecologic analysis
Taxonomic list comments:Relative abundance information: present (1 specimen collected), common (2-10 specimens collected), abundant (more than 10 specimens collected), very abundant (sample extremely rich in a given species)
Metadata
Database number:9926
Authorizer:A. Miller Enterer:K. Layou
Research group:marine invertebrate
Created:2001-02-01 07:40:14 Last modified:2001-08-30 17:52:51
Access level:the public Released:2001-02-01 12:02:00
Creative Commons license:CC BY
Reference information

Primary reference:

841. R. L. Ellison. 1965. Stratigraphy and Paleontology of the Mahantango Formation in south-central Pennsylvania. Pennsylvania Geological Survey Bulletin G48 1-298 [A. Miller/K. Layou]