Lamtsa (Ediacaran of Russian Federation)

Where: Arkhangelsk, Russian Federation (64.4° N, 37.1° E: paleocoordinates 62.3° S, 19.7° E)

• coordinate estimated from map

• local area-level geographic resolution

When: White Sea other zone, Lamtsa Formation, Ediacaran (635.0 - 541.0 Ma)

Environment/lithology: prodelta; lithified shale and lithified sandstone

• This assemblage is dominated by gray to pale brown laminated shale and siltstone. The most characteristic primary structure is a stratification consisting of laminations to very thin beds of shale, or thin shale-siltstone alternations. In addition, the assemblage comprises units (up to 20 m) of

•maroon shale with thin (1–2 mm to 10 cm) graded beds of volcanic ash that can sometimes be traced for several dozens of kilometers within this facies. As the facies progrades, it incorporates gray, fine-grained, thin (15–30 cm) sandstone beds with sharply defined lower boundaries, wave-rippled lamination, and rippled tops.

•This assemblage comprises packages (1.0–1.5 m) of gray and yellowishgray, fine-grained, thin-bedded sandstone units (0.1–0.5 m) interbedded with intervals (0.3–0.5 mup to 2 mthick) of graded siltstoneshale couplets and abundant gutter casts. The sandstone beds have sharp bases, fine upwards, and have rippled tops. Thinner beds tend to consist of fine horizontal laminations. Some of them contain gently curved laminasets which probably represent hummocky

•stratification. However, thicker units exhibit fining-upward textures, convoluted laminations, amalgamation surfaces, ball-and-pillow structure, isolated shale clasts, and wave ripple laminations.

Preservation: mold/impression

Primary reference: D. Grazhdankin. 2004. Patterns of distribution in the Ediacaran biotas: facies versus biogeography and evolution. Paleobiology 30(2):203-221 [M. Laflamme/M. Laflamme]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 91641: authorized by Marc Laflamme, entered by Marc Laflamme on 10.10.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

Palaeopascichnus
  -
Ediacaria
  -
Ediacaria sp. Sprigg 1947
Aspidella
  -
"Eoporpita sp." = Aspidella, "Cyclomedusa sp." = Aspidella
"Eoporpita sp." = Aspidella Billings 1872
"Cyclomedusa sp." = Aspidella Billings 1872
Inaria
  -
Inaria sp. Gehling 1988
 Bilateria -
Dickinsonia sp. Sprigg 1947