7-11 Mine (clay-ironstone horizon) (Carboniferous to of the United States)

Where: Columbiana County, Ohio (40.7° N, 80.7° W: paleocoordinates 7.4° S, 18.1° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Mahoning Formation (Conemaugh Group), Westphalian D to Westphalian D (309.8 - 301.5 Ma)

• Between the Mahoning Coal (considered equivalent to late Desmoinesian/Westphalian D) and Brush Creek (considered equivalent to early Missourian/Stephanian A)

• 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

Show authors, comments, and common names
Sphenopteridae
  - Sphenopteridae
Sphenopteris minutisecta, Sphenopteris cf. elegans
Sphenopteris cf. elegans Brongniart 1822
Equisetopsida
 Sphenophyllales -
Sphenophyllum majus, Sphenophyllum oblongifolium
Peltaspermopsida
 Peltaspermales - Peltaspermaceae
Odontopteris aequalis, Odontopteris brardii
Odontopteris brardii Brongniart 1825
 Radiatopses - Medullosaceae
Neuropteris ovata, Neuropteris scheuchzeri
Neuropteris heterophylla
  -
"Neuropteris heterophylla" = Imparipteris heterophylla
"Neuropteris heterophylla" = Imparipteris heterophylla Brongniart 1825
Spiropteris
  -
Spiropteris sp.
Spiropteris sp. Schimper 1869
may be assignable to either a filicopsid or a pteridosperm
Neuropteridae
  - Neuropteridae
Linopteris neuropteroides, Linopteris muensteri, Cyclopteris orbicularis, Cyclopteris trichomanoides
 Gigantopteridales - Gigantopteridaceae
"cf. Megalopteris sp." = Gigantopteris
"cf. Megalopteris sp." = Gigantopteris Geyler 1886
Cycadopsida
 Cycadales -
Taeniopteris lescuriana, Taeniopteris newberriana
Lescuropteris moorii
  -
Lescuropteris moorii
Lescuropteris moorii Lesquereux 1858
Polypodiopsida
 Cyatheales - Polypodiidae
"Pecopteris hemitelioides" = Hemitelites hemitelioides
"Pecopteris hemitelioides" = Hemitelites hemitelioides Brongniart 1834 scaly tree fern
 Marattiales - Marattiidae
Asterotheca sp.
Asterotheca sp. Presl 1845
Identification tentative due to poor preservation
 Equisetales - Equisetidae
Calamites suckowii, cf. Calamostachys sp., Annularia asteris, Annularia radiata, Annularia sphenophylloides, Annularia stellata
Calamites suckowii Brongniart 1828
cf. Calamostachys sp. Schimper 1869
Danaeites
  -
"Danaeites emersonii" = Danaeides
"Danaeites emersonii" = Danaeides
Pteropsida
 Filicinae -
Pecopteris arborescens, Pecopteris candolleana, cf. Pecopteris cyathea, Pecopteris lamuriana, Pecopteris miltonii, Pecopteris unita, "Alethopteris sp." = Pecopteris (Alethopteris)
"Alethopteris sp." = Pecopteris (Alethopteris) Sternberg 1825
Mixoneura
  -
Mixoneura sp.
Mixoneura sp. Weiss 1870
Lycopsida
  -
Lycopsida indet.
Lycopsida indet.
unidentified strobili (2)
Aphlebia
  -
Aphlebia sp.
Aphlebia sp. Presl 1838
may be assignable to either a filicopsid or a pteridosperm
 Cardiocarpales -
"Cardiocarpon spp." = Cardiocarpus
"Cardiocarpon spp." = Cardiocarpus Brongniart 1881
Pinopsida
 Cordaitanthales -
Cordaites cf. principalis
Alloiopteris
  -
Alloiopteris erosa