The formation was first established and described from the core of the Ust-Pinega borehole drilled in the settlement of Ust-Pinega, Arkhangelsk Region of Russia, where its thickness is 284 m. Its natural outcrops within the same region are known from the Onega Peninsula and the Winter Coast of the White Sea, as well as from small, isolated outcrops in the basin of the Onega River and on the northern slope of the Vetreny Poyas (Windy Belt) Ridge.[3]
The formation rests with erosion on Proterozoicterrigenous deposits or Archeancrystalline rocks. It is subdivided, from bottom to top, into the following Subformations (initially defined as "Beds" by A.F. Stankovsky, 1985): Tamitsa, Lyamtsa, Arkhangelsk, Verkhovka, Syuzma, Vaizitsa, and Zimnegory. It is unconformably overlain by deposits of the Ediacaran Mezen Formation, as well as by Paleozoic or Quaternary sediments.
In 2003, D.V. Grazhdankin proposed an alternative subdivision scheme for these deposits, based on the original scheme by A.F. Stankovskiy. This scheme includes the Lyamtsa (= Lyamtsa + Arkhangelsk Beds), the Verkhovka (= Verkhovka + Syuzma Beds), and the Zimnegory (= Vaizitsa + Zimnegory Beds) Formations. In this revision, the use of the Ust' Pinega Formation was abandoned in favor of these three formations.[4]
Currently, the Ust' Pinega Formation and its subformations remain the official stratigraphic scheme used on state geological maps of Russia.
Dating
The Lyamtsa, Verkhovka and Vaizitsa Subformations contain volcanic ashes. Zircon U-Pb dating of volcanic tuffs from the Verkhovka and Vaizitsa beds has yielded ages of 557.28±0.14 Ma and 552.96±0.19 Ma, respectively.[5][2] Furthermore, an Rb–Sr age of 565±9 Ma was obtained for clays of the Arkhangelsk Subformation.[1] The formation is unconformably overlain by the deposits of the Mezen Formation, from the lower part of which a U-Pb age of 550.2±4.6 Ma has been obtained for tuffites.[6]
Paleobiota
The Ustʹ Pinega Formation is home to many rare and common Ediacaran fauna, from the well known motile forms such as Dickinsonia and Kimberella,[7] 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.[8]
^ abGolubkova, E. Yu.; Zaitseva, T. S.; Tretyachenko, V. V.; Kushim, E. A.; Kuznetsov, A. B.; Turchenko, T. L.; Silivanov, M. O. (April 2025). "The Redkino Biota and the Rb–Sr Age of Vendian Deposits from the North of the East European Platform". Stratigraphy and Geological Correlation. 33 (2): 157–175. doi:10.1134/S086959382470031X.
^ abcYang, Chuan; Rooney, Aleksey D.; Condon, Daniel J.; Li, Xian-Hua; Grazhdankin, Dmitriy V.; Bowyer, Frederick T.; Hu, Chao; Macdonald, Francis A.; Zhu, Maoyan (5 November 2021). "The tempo of Ediacaran evolution". Science Advances. 7 (45) eabi9643. doi:10.1126/sciadv.abi9643. PMC8565906.
^ abcdefghijklmnopqrstuMartin, M. W.; Grazhdankin, D. V.; Bowring, S. A.; Evans, D. A. D.; Fedonkin, M. A.; Kirschvink, J. L. (5 May 2000). "Age of Neoproterozoic Bilatarian Body and Trace Fossils, White Sea, Russia: Implications for Metazoan Evolution". Science. 288 (5467): 841–845. doi:10.1126/science.288.5467.841.
^Llanos, M; Tait, J; Popov, V; Abalmassova, A (15 December 2005). "Palaeomagnetic data from Ediacaran (Vendian) sediments of the Arkhangelsk region, NW Russia: An alternative apparent polar wander path of Baltica for the Late Proterozoic–Early Palaeozoic". Earth and Planetary Science Letters. 240 (3–4): 732–747. doi:10.1016/j.epsl.2005.09.063. hdl:11336/92776.
^ abFedonkin, M.A.; Simonetta, A; Ivantsov, A.Y. (2007), "New data on Kimberella, the Vendian mollusc-like organism (White sea region, Russia): palaeoecological and evolutionary implications", in Vickers-Rich, Patricia; Komarower, Patricia (eds.), The Rise and Fall of the Ediacaran Biota, Special publications, vol. 286, London: Geological Society, pp. 157–179, doi:10.1144/SP286.12, ISBN 978-1-86239-233-5, OCLC156823511
^ abFedonkin, M. A.; Vickers-Rich, P.; Swalla, B. J.; Trusler, P.; Hall, M. (2012). "A new metazoan from the Vendian of the White Sea, Russia, with possible affinities to the ascidians". Paleontological Journal. 46: 1. doi:10.1134/S0031030112010042.
^Fedonkin, Mikhail A. (January 2002). "Andiva ivantsovi gen. et sp. n. and related carapace‐bearing Ediacaran fossils from the Vendian of the Winter Coast, White Sea, Russia". Italian Journal of Zoology. 69 (2): 175–181. doi:10.1080/11250000209356456.
^ abcIvantsov, A. Yu. (2004). "New Proarticulata from the Vendian of the Arkhangel'sk Region". Paleontological Journal. 38 (3): 247. CiteSeerX10.1.1.738.7043.
^Fedonkin, M. A. (1979). "Paleoichnology of Precambrian and Early Cambrian". In Sokolov, B. S. (ed.). Paleontology of Precambrian and Early Cambrian (in Russian). Leningrad: USSR Academy of Sciences. pp. 183–192.
^M. A. Fedonkin (1985). "Systematic Description of Vendian Metazoa". Vendian System: Historical–Geological and Paleontological Foundation. 1: Paleontology. Moscow: Nauka: 70–106.
^Fedonkin, M. A. (1980). "Fossil traces of Precambrian Metazoa". SSSR Series Geology. 1: 39–46.
^ abcdLeonov, M. V. (October 2007). "Macroscopic plant remains from the base of the Ust'-Pinega formation (Upper Vendian of the Arkhangelsk Region)". Paleontological Journal. 41 (6): 683–691. doi:10.1134/S0031030107060123.
^Istchenko, A. A. (1983). "To the question about stages of development of the algal flora of the South-Western part of Eastern-European platform". Fossil Fauna and Flora of the Ukraine. III Session of the Ukrainian Paleontological Society: 70–75.
^Ivantsov, A. Yu. (May 2013). "Trace fossils of precambrian metazoans "Vendobionta" and "Mollusks"". Stratigraphy and Geological Correlation. 21 (3): 252–264. doi:10.1134/S0869593813030039.