Exposure 42, Bed 5b, Lopsiya River (Eastern slope of the Subpolar Urals) (Jurassic of Russian Federation)

Where: Siberia, Russian Federation (62.5° N, 60.3° E: paleocoordinates 58.5° N, 56.7° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Early/Lower Kimmeridgian (155.7 - 150.8 Ma)

• Kimmeridgian Stage, Lower Substage, Rasenia evoluta Zone, Eurasenia pseudouralensis Subzone;

•thickness: 2.0 m

• bed-level stratigraphic resolution

Environment/lithology: open shallow subtidal; lithified, brown, gray, argillaceous, sandy siltstone

• The explored Kimmeridgian section denuded along the Lopsiya River formed under the embayment conditions of an epicontinental West Siberian sea, covering the territory of more than 2 mln km^2. This Lyapinsky Bay was rather shallow and opened toward the NNE. The narrow band of the Uralian Peninsula seperated it from the Timon-Pechora Sea in the west, and the small Berezovsky Archipelago seperated it from the West Siberian Sea in the east.
• Brownish-gray lumpy sandy-clayey silts with rare fragments of mineralized wood and pyritized concretions similar to those from Bed 5a. At the level 1.5 m from the bottom occurs an interbed of large calcareous concretions. An interbed of gray plastic clay 0.3 m thick lies one meter apart from the top. At a distance of 0.4 m from the roof silt changes to large-lumpy fine- and medium-grained sandstone consolidated in places into a concretionary interbed.

Size class: macrofossils

Primary reference: V. A. Zakharov, F. Baudin, O. S. Dzyuba, V. Daux, K. V. Zverev and M. Renard. 2005. Isotopic and faunal record of high paleotemperatures in the Kimmeridgian of Subpolar Urals. Russian Geology and Geophysics 46(1):3-20 [M. Aberhan/S. Nurnberg]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 58774: authorized by Martin Aberhan, entered by Sabine Nürnberg on 24.02.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Goniatitida - Prionoceratidae
Amoeboceras (Amoebites) kitchini Salfeld 1915 ammonite
Amoeboceras (Amoebites) spathi Schulgina 1960 ammonite
 Ammonitida - Aulacostephanidae
Prorasenia bowerbanki Spath 1935 ammonite
Prorasenia hardyi Spath 1935 ammonite
 Ammonitida - Perisphinctidae
Rasenia (Eurasenia) pseudouralensis Mesezhnikov 1984 ammonite
Rasenia (Rasenia) inconstans Spath 1935 ammonite
Rasenia (Rasenia) evoluta Spath 1935 ammonite
 Belemnitida -
Bivalvia
 Pectinida - Pectinoidae
 Pectinida - Oxytomidae
 Ostreida - Pinnidae
Pinna sp. Linnaeus 1758 oyster
 Ostreida - Bakevelliidae
Aguilerella sp. Chavan 1951 oyster
 Ostreida - Gryphaeidae
Liostrea sp. Douvillé 1904 oyster
 Arcida - Parallelodontidae
 Pholadomyida - Pholadomyidae
Pholadomya sp. Sowerby 1823 clam
 Cardiida - Cardiidae
Protocardia sp. Beyrich 1845 cockle
 Carditida - Astartidae