Dearden Moor, Gastrioceras cumbriense Marine Band, shale Unit 3 (Carboniferous of the United Kingdom)

Also known as Dearden Moor, Gastrioceras cumbriense Marine Band, shale Unit 3, the acme shale

Where: England, United Kingdom (53.7° N, 2.3° W)

• Paleocoordinates: 10.6° S, 1.7° E (Wright 2013)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Gastrioceras cumbriense Marine Band ammonoid zone, shale Unit 3 Member (Gastrioceras cumbriense Marine Band Formation), Yeadonian (320.0 - 318.7 Ma)

• The Gastrioceras cumbriense Marine Band generally does not exceed 60cm in thickness. The band is split into five units, the lower barren shales (Unit 1), the advance shales (Unit 2), the acme shales (Unit 3), the retreat shales (Unit 4), and the upper barren shales (Unit 5).

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified, pyritic, black shale and lithified, gray shale

• Unit 3: The continuing transition and deepening of the sea caused a rapid transition to conditions of black paper shale deposition. The development of the shale appears to be synchronous as it contains a consistant pelagic fauna and has a widespread spatial distripbution throughout the north of England. The shales display planar stratified bedding planes with a spacing of 0.5 to 0.75 mm. There is little evidence for wave or current activity or bioturbation. At all localities the presence of pyrite blebs around which stratification is deflected is believed to indicate primary pore filling as a shallow depth of burial in tyhe sulphate reduction zone. ... The fauna of the balck shale is dominated by the thickshelled goniatite phase at the four easterly localities, whereas a more diverse benthic assemblge occurs as the two westerly localities [does not include Dearden Moor], wherethe thin-shelled Anthracoceratites and Posidonia predomminate over Gastrioceras. At Oxenhope and Dearden Moors the black shale is divided into two by a wavy-stratified grey shale with a much sparser fauna. The reduction in fossil abundance suggests that the grey shale represents a brief interruption of deposition from suspension by sediment-laden currents.

Size class: macrofossils

Primary reference: P. B. Wignall. 1987. A biofacies analysis of the Gastrioceras cumbriense marine band (Namurian) of the central Pennines. Proceedings of the Yorkshire Geological Society 46(2):111-121 [J. Alroy/C. Simpson/M. Uhen]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 41224: authorized by John Alroy, entered by Carl Simpson on 09.07.2004

Creative Commons license: CC0 (CC0)

Taxonomic list

Show authors, comments, and common names
Polypodiopsida
 Equisetales - Equisetidae
cf. Calamites sp.
cf. Calamites sp. Suckow 1784
Cephalopoda
 Ammonoida - Gastrioceratidae
Gastrioceras cumbriense, Gastrioceras crenulatum, Gastrioceras aff. subcrenatum, Gastrioceras spp.
Gastrioceras spp. Hyatt 1884 ammonite
Juvenile
 Ammonoida - Bisatoceratidae
Homoceratoides aff. divaricatus
 Ammonoida - Dimorphoceratidae
Anthracoceratites sp.
Anthracoceratites sp. Ramsbottom 1970 ammonite
 Nautiloidea -
Nautiloidea indet.
Nautiloidea indet. Agassiz 1847 nautiloid
Narrow angle orthocone
Gastropoda
  -
Gastropoda indet.
Gastropoda indet. Cuvier 1795 snail
Small
Bivalvia
  -
Bivalvia indet.
Bivalvia indet. Linnaeus 1758 clam
Small
 Ostreida - Pterineidae
Caneyella cf. multirugata
 Pectinida - Pterinopectinidae
Dunbarella elegans
 Pectinida - Aviculopectinidae
Aviculopecten sp.
Aviculopecten sp. M'Coy 1851 scallop
Gnathostomata
  -
Osteichthyes indet.
Osteichthyes indet. bony fish
Palaeoniscid scales
Osteichthyes
 Elonichthyiformes - Acrolepididae
Acrolepis sp.
Acrolepis sp. Agassiz 1833 ray-finned fish
Scales