7-11 Mine Clay-Ironstone Horizon (Carboniferous to of the United States)

Where: Columbiana County, Ohio (40.6° N, 80.6° W: paleocoordinates 7.0° S, 17.6° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Barren shale sequence Member (Mahoning Formation), Podolskian to Podolskian (311.4 - 300.2 Ma)

• Section (Figure 1) on p. 48.

• bed-level stratigraphic resolution

Environment/lithology: lacustrine - small; ferruginous, sideritic, silty claystone

• Flocculation (adhesion of clays together) occurred. Very low energy regime. Interpreted as an oxbow lake (p. 50)
• Nine distinct, resistant, laterally continuous, clay-ironstone interbeds (ranging from 3.1-12.2 cm in thickness) occur between 0.3 and 3.8 m of the lower contact. These beds are composed of clay-siderite with small amounts of silty impurity.

Size class: macrofossils

Preservation: adpression

Primary reference: M. A. McComas. 1988. Upper Pennsylvanian compression floras of the 7-11 Mine, Columbiana County, northeastern Ohio. Ohio Journal of Science 88:48-52 [H. Sims/S. Ostrowski]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 11187: authorized by Hallie Sims, entered by Summer Ostrowski on 23.07.2001, edited by Alistair McGowan and Jason Cassara

Creative Commons license: CC BY (attribution)

Taxonomic list

Neuropteris heterophylla
"Neuropteris heterophylla" = Imparipteris heterophylla
"Neuropteris heterophylla" = Imparipteris heterophylla Brongniart 1825
 Filicinae -
Lescuropteris moorii
Lescuropteris moorii Lesquereux 1858
Mixoneura sp. Weiss 1870
 Marattiales - Marattiidae
Asterotheca sp. Presl 1845
Identification tentative due to poor preservation
 Equisetales - Equisetidae
 Cyatheales - Polypodiidae
"Pecopteris hemitelioides" = Hemitelites hemitelioides
"Pecopteris hemitelioides" = Hemitelites hemitelioides Brongniart 1834 scaly tree fern
Lycopsida indet.
unidentified strobili (2)
"Danaeites emersonii" = Danaeides
"Danaeites emersonii" = Danaeides
  - Sphenopteridae
Spiropteris sp. Schimper 1869
may be assignable to either a filicopsid or a pteridosperm
Aphlebia sp. Presl 1838
may be assignable to either a filicopsid or a pteridosperm
 Gigantopteridales - Gigantopteridaceae
"cf. Megalopteris sp." = Gigantopteris
"cf. Megalopteris sp." = Gigantopteris Geyler 1886
 Cycadales -
  - Neuropteridae
 Sphenophyllales -
 Peltaspermales - Peltaspermaceae
 Radiatopses - Medullosaceae
 Cardiocarpales -
"Cardiocarpon spp." = Cardiocarpus
"Cardiocarpon spp." = Cardiocarpus Brongniart 1881
 Cordaitanthales -