The Ust Pinega Formation is an Upper

Ediacaran The Ediacaran ( ) is a geological period of the Neoproterozoic geologic era, Era that spans 96 million years from the end of the Cryogenian Period at 635 Million years ago, Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last ...

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock expo ...

exposed along the banks of the Syuzma and

Onega River The Onega (; ) is a river in Kargopolsky, Plesetsky, and Onezhsky Districts of Arkhangelsk Oblast in Russia. The Onega connects Lake Lacha with the Onega Bay in the White Sea southwest of Arkhangelsk, flowing in the northern direction. The disc ...

s in

Arkhangelsk Oblast Arkhangelsk Oblast ( rus, Архангельская область, p=ɐrˈxanɡʲɪlʲskəjə ˈobɫəsʲtʲ) is a federal subjects of Russia, federal subject of Russia (an oblast). It includes the Arctic Ocean, Arctic archipelagos of Franz ...

, northwestern

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

, and spans from around 580 Ma to 550 Ma, with fossilferous stones restricted to between 565 and 555 Ma. It also preserves a wealth of rare Ediacaran fossils, like '' Zolotytsia'', ''

Ventogyrus ''Ventogyrus'' is an Ediacaran fossil found in the White Sea-Arkhangelsk region of Russia. It was first discovered in the Teska member of the Ust'-Pinega formation, in a thick lens of sandstone, originally sand dumped by storm waves that cut a de ...

'' and ''

Bomakellia ''Bomakellia'' is an extinct petalonamid from the Late Ediacaran. It is estimated to have lived some 555 million years ago, and has only been found in the Ustʹ Pinega Formation in Northwestern Russia. Originally described as a primitive arthrop ...

''.

Dating

The Ustʹ Pinega Formation is relatively large, and using zircon U-Pb dating, a date of had been recovered for the top of the formtion, whilst the known base of the formation is restricted to . As for the lower and upper dates of the fossiliferous units within the formtaion, using the Rb–Sr dating method, the lowest fossiliferous unit of the Ustʹ Pinega Formation has been dated to , whilst the upper-most fossiliferous unit was dated using zircon U-Pb dating, which had recovered a date of .

Paleobiota

The Ustʹ Pinega Formation is home to many rare and common Ediacaran fauna, from the well known motile forms such as ''

Dickinsonia ''Dickinsonia'' is a genus of extinct organism that lived during the late Ediacaran period in what is now Australia, China, Russia, and Ukraine. It had a round, bilaterally symmetric body with multiple segments running along it. It could range f ...

'' and ''

Kimberella ''Kimberella'' is an extinct genus of marine bilaterian known only from rocks of the Ediacaran period. The slug-like organism fed by scratching the microbial surface on which it dwelt in a manner similar to the gastropods, although its affinity ...

'', to the rarer, more elusive forms like ''Ventogyrus'' and ''Zolotytsia''. All forms within this formation are preserved in layers of ash beds, which are not only good at preserving the fine exterior details of organisms, but also their internals, like ''

Burykhia ''Burykhia hunti'' is an Ediacaran fossil from the White Sea region of Russia dating to . It is considered of possibly ascidian affinity, due to the sac-like morphology and a series of distinctly perforated bands reminiscent of a tunicate pharyn ...

''.

Proarticulata

Petalonamae

Trilobozoan

Cnidarian

Chordata

Annelida

''incertae sedis''

Flora

Ichnogenera

References

{{DEFAULTSORT:Ust' Pinega Formation Geology of European Russia Geologic formations of Russia Ediacaran Europe Geography of Arkhangelsk Oblast Long stubs with short prose