Tentaculites-Actinopteria Comm., Up. Noulette Fm., Mericourt 30 Borehole, Artois (Devonian of France)

Where: France (50.5° N, 2.5° E: paleocoordinates 25.9° S, 4.5° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Upper Member (Noulette Formation), Lochkovian (419.2 - 410.8 Ma)

• Upper Member of the Noulette Formation (='Schistes de Mericourt' sensu Barrois et al. (1922)) in the Lievin Group.

• member-level stratigraphic resolution

Environment/lithology: marine; condensed, phosphatic shale and condensed, phosphatic siltstone

• General statement of Central Armorican trough during Llandovery through Lochkovian: "depositional patterns typical of a platform environment...Silurian is mainly an alternating succession of unfossiliferous sandstones and locally fossiliferous black shales...The arenaceous deposits are probably related to the eustatic regression and corresponding high sedimentation rate during the Pridolian and Lochkovian...Outside the A. Massif the Pridoli-Lochkovian succesion in Artois (boreholes) is characterized by shallow marine shales and limestones overlain by areanceous deposits that correspond to the Early Devonian transgression."

•For this Community: Phosphate nodules said to be reworked from previous phosphate layer, indicating "high hydrodynamic level, which is confirmed by numerous tempestites." Remains disarticulated. Faunal composition and spores said to indicate nearshore position, probably subtidal, BA 2.

• General statement: "In Brittany there are two kinds of black shale and limestone deposits during the Llandovery to lowermost Devonian interval: (1) black shales (commonly described as sapropelites) are widespread in space and time and (2) black, micritic limestones or argillaceous limestones are restricted to two localities in the eastern part of the Armorican Massif. The black shales are very rich in organic matter and locally contain detrital mica, pyrite, and nodules..."

•For this community: "dark shale and siltstone with phosphatic nodules, indicating a shallow water deposit, and en episodic, very low rate of sedimentation."

Primary reference: P. R. Racheboeuf. 1999. Lower Silurian to Lower Devonian communities from the Armorican Massif (western France) and Artois (northern France). In A. J. Boucot, J. D. Lawson (eds.), Paleocommunities--a case study from the Silurian and Lower Devonian 260-270 [M. Foote/M. Foote/P. Wagner]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 26121: authorized by Michael Foote, entered by Michael Foote on 04.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Lophophorata
 Tentaculitida - Tentaculitidae
Tentaculites sp.
Tentaculites sp. von Schlotheim 1820
Rhynchonellata
 Spiriferida - Delthyrididae
Howellella angustiplicata
 Terebratulida - Meganterididae
Mutationella barroisi
Bivalvia
 Ostreida - Pterineidae
Actinopteria triculta
 Cardiidia - Grammysiidae
Grammysia lerichei
 Nuculanida - Malletiidae
Palaeoneilo humenryi
Gastropoda
  -
Gastropoda indet.
Gastropoda indet. Cuvier 1795 snail
Deuteropoda
  -
Ostracoda indet.
Ostracoda indet. Latreille 1802 ostracod
"etc."
Ostracoda
 Platycopida - Kloedenellidae
Poloniella sp.
 Palaeocopida -
Carinokloedenia sp.
 Beyrichicopida - Bolliidae
Ulrichia sp.
Ulrichia sp. Jones 1890 ostracod
Trilobita
 Phacopida - Acastidae
Acastella artesia
 Phacopida - Homalonotidae
Parahomalonotus vialai