Shale on South Flank of Tindouf Basin (Pridoli/Gedinne Part) (Silurian to of Algeria)

Where: Algeria (27.5° N, 7.5° W: paleocoordinates 60.4° S, 20.5° E)

• coordinate estimated from map

• local area-level geographic resolution

When: Pridoli to Pridoli (423.0 - 391.9 Ma)

• "The brachiopod, trilobite, and graptolite fauna of this sandstone-shale part of the stratigrahpic column indicates that it is of Pridoli to Gedinne age and supports Gevin's (1960, p. 98) suggestion that the Silurian age deposits are continuous with those of Early Devonian age. He records Siegen and Emsian age sandstones stratigraphically above the probable Gedinne age beds. A conglomerate layer or an interval of conglomeratic sandstone occurs at the base of the Siegen age beds as well as in the interval of the Gedinne age beds."

• formation-level stratigraphic resolution

Environment/lithology: transition zone or lower shoreface; shale and sandstone

• Essentially at Pridoli shoreline, according to paleogeographic map of ref. 7455.

•SEP environmental call based on given info and regional context

• "Graptolite-bearing shales grade stratigraphically upward into interbedded shales, sandstones, some conglomerates, and a few limestones."

Primary reference: W. B. N. Berry and A. J. Boucot. 1973. Correlation of the African Silurian rocks. Geological Society of America Special Paper 147:1-83 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 27456: authorized by Michael Foote, entered by Michael Foote on 06.12.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Trilobita
 Phacopida - Dalmanitidae
Dalmanites sp. Barrande 1852 trilobite
 Phacopida - Acastidae
Acaste sp. Goldfuss 1843 trilobite
Acaste downingiae Murchison 1839 trilobite
Strophomenata
 Strophomenida - Furcitellidae
"Strophomena imbrex" = Megamyonia arethusa
"Strophomena imbrex" = Megamyonia arethusa Billings 1862
Rhynchonellata
 Spiriferida - Spiriferidae
 Athyridida - Meristellidae
 Atrypida - Atrypidae
 Lophophorata -
Tentaculitida indet. Ljaschenko 1955
Bivalvia
 Cyrtodontida - Cardiolidae
Cardiola sp. Broderip 1839 clam
Cephalopoda
 Orthoceratoidea -
 Orthocerida - Orthoceratidae
Orthoceras sp. Breynius 1832
Crinoidea
 Monobathrida - Periechocrinitidae
cf. Gennaeocrinus sp. Wachsmuth and Springer 1881 Sea lily
Pterobranchia
 Graptoloidea - Monograptidae
Monograptidae indet. Lapworth 1873 graptolite
"Monograptids, probably of the M. hercynicus group"
Monograptus sp. graptolite