{{Short description|Geological formation in northwestern Russia}} {{Infobox rockunit | name = Ustʹ Pinega Formation | image = | caption = | period = Ediacaran | age = Ediacaran {{fossil range|575|550|ref= <ref name="Golubkova">{{cite journal |last1=Golubkova |first1=E. Yu. |last2=Zaitseva |first2=T. S. |last3=Tretyachenko |first3=V. V. |last4=Kushim |first4=E. A. |last5=Kuznetsov |first5=A. B. |last6=Turchenko |first6=T. L. |last7=Silivanov |first7=M. O. |title=The Redkino Biota and the Rb–Sr Age of Vendian Deposits from the North of the East European Platform |journal=Stratigraphy and Geological Correlation |date=April 2025 |volume=33 |issue=2 |pages=157–175 |doi=10.1134/S086959382470031X}}</ref><ref name="Yang2021"/>}} | type = Geological Formation | prilithology = Argillite | otherlithology = Sandstone, Siltstone, Clay | namedfor = Ust-Pinega | namedby = | region = Arkhangelsk Oblast, Vologda Oblast, Kirov Oblast, Komi Republic, Republic of Karelia | country = Russia | coordinates = {{coord|64|09|00|N|41|56|00|E|display=inline,title}} | unitof = | subunits = Tamitsa, Lyamtsa, Arkhangelsk, Verkhovka, Syuzma, Vaizitsa and Zimnegory Subformations | underlies = Mezen Formation | overlies = different Archean and Proterozoic rocks | thickness = >751 m | extent = >970 km | area = | map = {{Location map+ | Russia#Russia Arkhangelsk Oblast | relief = 1 | width = 200 | float = center | places = {{Location map~ | Russia#Russia Arkhangelsk Oblast | lat_deg = 64.09 | lon_deg = 41.56 | mark = Dark Green 004040 pog.svg | marksize = 10 }} }} }}
The '''Ust{{softsign}} Pinega Formation''' is an Upper Ediacaran geological formation in northwestern Russia. It spans from around {{val|575|ul=Ma}} to {{val|550|ul=Ma}} and contains fossils of the Ediacaran biota throughout its sequence.<ref name="Yang2021"/>
== Geology ==
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.<ref name="Sokolov"/>
The formation rests with erosion on Proterozoic terrigenous deposits or Archean crystalline 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.<ref name="Grazhdankin2003">{{cite journal |first1=D. V. |last1=Grazhdankin |title=Structure and Depositional Environment of the Vendian Complex in the Southeastern White Sea Area |url=https://repository.geologyscience.ru/handle/123456789/32406 |journal=Stratigraphy and Geological Correlation|volume=11|issue=4|pages=313–331 |access-date=2 May 2025 |date=2003}}</ref>
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 {{val|557.28|0.14|ul=Ma}} and {{val|552.96|0.19|ul=Ma}}, respectively.<ref name="Martin"/><ref name="Yang2021">{{cite journal |last1=Yang |first1=Chuan |last2=Rooney |first2=Aleksey D. |last3=Condon |first3=Daniel J. |last4=Li |first4=Xian-Hua |last5=Grazhdankin |first5=Dmitriy V. |last6=Bowyer |first6=Frederick T. |last7=Hu |first7=Chao |last8=Macdonald |first8=Francis A. |last9=Zhu |first9=Maoyan |title=The tempo of Ediacaran evolution |journal=Science Advances |date=5 November 2021 |volume=7 |issue=45 |article-number=eabi9643 |doi=10.1126/sciadv.abi9643|pmc=8565906 }}</ref> Furthermore, an Rb–Sr age of {{val|565|9|ul=Ma}} was obtained for clays of the Arkhangelsk Subformation.<ref name="Golubkova"/> The formation is unconformably overlain by the deposits of the Mezen Formation, from the lower part of which a U-Pb age of {{val|550.2|4.6|ul=Ma}} has been obtained for tuffites.<ref name="Llanos">{{cite journal |last1=Llanos |first1=M |last2=Tait |first2=J |last3=Popov |first3=V |last4=Abalmassova |first4=A |title=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 |journal=Earth and Planetary Science Letters |date=15 December 2005 |volume=240 |issue=3-4 |pages=732–747 |doi=10.1016/j.epsl.2005.09.063|hdl=11336/92776 |hdl-access=free }}</ref>
== 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'',<ref name=Fedonkin2007>{{The Rise and Fall of the Ediacaran Biota|chapter=New data on ''Kimberella'', the Vendian mollusc-like organism (White sea region, Russia): palaeoecological and evolutionary implications|author=Fedonkin, M.A. |author2=Simonetta, A |author3=Ivantsov, A.Y. |pages=157–179 |doi=10.1144/SP286.12}}</ref> 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''.<ref name="Fedonkin2012">{{Cite journal | last1 = Fedonkin | first1 = M. A. | last2 = Vickers-Rich | first2 = P. | last3 = Swalla | first3 = B. J. | last4 = Trusler | first4 = P. | last5 = Hall | first5 = M. | title = A new metazoan from the Vendian of the White Sea, Russia, with possible affinities to the ascidians | journal = Paleontological Journal | volume = 46 | pages = 1 | year = 2012 | doi = 10.1134/S0031030112010042 }}</ref> {{Paleobiota-key-compact}}
=== Proarticulata ===
{| class="wikitable sortable" style="width:70%;" |- !Genus !Species !Notes !Images |- |''Andiva<ref>{{cite journal |last1=Fedonkin |first1=Mikhail A. |title=Andiva ivantsovi gen. et sp. n. and related carapace‐bearing Ediacaran fossils from the Vendian of the Winter Coast, White Sea, Russia |journal=Italian Journal of Zoology |date=January 2002 |volume=69 |issue=2 |pages=175–181 |doi=10.1080/11250000209356456}}</ref>'' | *''A. ivantsovi'' |Elongated oval motile organism. |center|100px |- |''Archaeaspinus<ref name=Ivantsov/>'' | *''A. fedonkini'' |Oval motile organism. |center|100px |- |''Armillifera<ref name=Sokolov/>'' | *''A. parva'' |Elongated oval motile organism. |center|100px |- |''Cephalonega<ref name=Sokolov/>'' | *''C. stepanovi'' |Oval motile organism. |center|100px |- |''Cyanorus<ref name=Ivantsov>{{Cite journal|last=Ivantsov|first=A. Yu.|date=2004|title=New Proarticulata from the Vendian of the Arkhangel'sk Region|journal=Paleontological Journal|volume=38|issue=3|pages=247|citeseerx=10.1.1.738.7043}}</ref>'' | *''C. singularis'' |Elongated motile organism. |center|100px |- |''Dickinsonia<ref name=Sokolov>{{cite journal |last1=Sokolov |first1=Boris S. |last2=Fedonkin |first2=Mikhail A. |title=The Vendian as the Terminal System of the Precambrian |journal=Episodes |date=1 March 1984 |volume=7 |issue=1 |pages=12–19 |doi=10.18814/epiiugs/1984/v7i1/004|doi-access=free }}</ref><ref name=Martin>{{cite journal |last1=Martin |first1=M. W. |last2=Grazhdankin |first2=D. V. |last3=Bowring |first3=S. A. |last4=Evans |first4=D. A. D. |last5=Fedonkin |first5=M. A. |last6=Kirschvink |first6=J. L. |title=Age of Neoproterozoic Bilatarian Body and Trace Fossils, White Sea, Russia: Implications for Metazoan Evolution |journal=Science |date=5 May 2000 |volume=288 |issue=5467 |pages=841–845 |doi=10.1126/science.288.5467.841}}</ref>'' | *''Dickinsonia'' sp. |Oval to elongated motile organism. |center|100px |- |''Karakhtia<ref name=Ivanstov2>{{Cite journal |last1=Ivantsov |first1=Andrey Yu. |last2=Malakhovskaya |first2=Ya.E. |last3=Serezhnikova |first3=E.A. |date=January 2004 |title=Some problematic fossils from the Vendian of the southeastern White Sea Region |url=https://www.researchgate.net/publication/287445709 |journal=Paleontological Journal |volume=38 |issue=1 |pages=1–9 |via=researchgate.net}}</ref>'' | *''K. nessovi'' |Oval motile organism. |center|100px |- |''Keretsa<ref name=Ivantsov2017>{{Cite journal|author=A.Yu. Ivantsov |year=2017 |title=The most probable Eumetazoa among late Precambrian macrofossils |journal=Invertebrate Zoology |volume=14 |issue=2 |pages=127–133 |doi=10.15298/invertzool.14.2.05 |doi-access=free }}</ref>'' | *''K. brutoni'' |Elongated motile organism. | |- |''Lossinia<ref name=Ivantsov_2007>{{cite journal| author=Ivantsov, A. Yu.| title = Small Vendian transversely Articulated fossils| journal = Paleontological Journal| volume = 41| issue = 2| date = April 2007| doi = 10.1134/S0031030107020013| url = https://www.academia.edu/2352394| pages=113–122| s2cid = 86636748}}</ref>'' | *''L. lissetskii'' |Elongated motile organism. |center|100px |- |''Ovatoscutum<ref name=Sokolov/><ref name=Martin/>'' | *''O. concentricum'' |Rounded motile organism. |center|100px |- |''Palaeoplatoda<ref name=Sokolov/><ref name="Fedonkin 1979">{{Cite book|title=Paleontology of Precambrian and Early Cambrian|last=Fedonkin|first=M. A.|publisher=USSR Academy of Sciences|year=1979|editor-last=Sokolov|editor-first=B. S.|location=Leningrad|pages=183–192|language=ru|chapter=Paleoichnology of Precambrian and Early Cambrian}}</ref>'' | *''P. segmentata'' |Elongated motile organism. | |- |''Paravendia<ref name=Ivantsov/>'' | *''P. janae'' |Elongated motile organism. |center|100px |- |''Vendia<ref name=Sokolov/><ref name=Martin/>'' | *''V. sokolovi'' *''V. rachiata'' |Elongated motile organism. | |- |''Yorgia<ref name=Martin/>'' | *''Y. waggoneri'' |Oval motile organism. |center|100px |- |}
=== Petalonamae ===
{| class="wikitable" style="width:70%;" |- !Genus !Species !Notes !Images |- |''Bomakellia<ref name=Fedonkin1985>{{cite journal |author=M. A. Fedonkin |year=1985 |title=Systematic Description of Vendian Metazoa |journal=Vendian System: Historical–Geological and Paleontological Foundation |volume=1: Paleontology |location=Moscow: Nauka |pages=70–106}}</ref>'' | *''B. kelleri'' |Sessile frondose organism. |center|100px |- |''Charnia<ref name=Sokolov/><ref name=Martin/>'' | *''Charnia'' sp. |Sessile frondose organism. |center|100px |- |''Charniodiscus<ref name=Sokolov/>'' | *''Charniodiscus'' sp. |Sessile frondose organism. |center|100px |- |''Pteridinium<ref name=Sokolov/>'' | *''Pteridinium'' sp. |Sessile frondose organism. |center|100px |- |''Ramellina''<ref name="Fedonkin1980">{{Cite journal|last=Fedonkin|first=M. A.|date=1980|title=Fossil traces of Precambrian Metazoa|journal=SSSR Series Geology|volume=1|pages=39–46}}</ref> | *''R. pennata'' |Sessile frondose organism. | |- |}
=== Trilobozoan ===
{| class="wikitable" style="width:70%;" |- !Genus !Species !Notes !Images |- |''Albumares<ref name=Sokolov/>'' | *''A. brunsae'' |Tri-radial organism. |center|100px |- |''Anfesta<ref name=Sokolov/><ref name=Martin/>'' | *''A. stankovskii'' |Tri-radial organism. |center|100px |- |''Tribrachidium<ref name=Sokolov/><ref name=Martin/>'' | *''T. heraldicum'' |Tri-radial organism. |center|100px |- |}
=== Cnidarian ===
{| class="wikitable sortable" style="width:70%;" |- !Genus !Species !Notes !Images |- |''Bonata<ref name=Sokolov/>'' | *''B. septata'' |Discoid organism. | |- |''Brachina<ref name=Sokolov/>'' | *''Brachina'' sp. |Discoid organism. | |- |''Ediacaria<ref name=Sokolov/><ref name=Martin/>'' | *''Ediacaria'' sp. |Discoid organism. |center|100px |- |''Eoporpita<ref name=Sokolov/><ref name=Martin/>'' | *''E. medusa.'' |Discoid organism. | |- |''Inaria<ref name=Martin/>'' | *''I. karli'' |Sac-like organism. |center|100px |- |''Medusinites<ref name=Sokolov/>'' | *''Medusinites'' sp. |Discoid organism. |center|100px |- |''Staurinidia<ref name=Sokolov/><ref name=Martin/>'' | *''S. crucicula'' |Discoid organism. |center|100px |- |''Tirasiana<ref name=Sokolov/>'' | *''Tirasiana'' sp. |Discoid organism. | |- |''Zolotytsia'' | *''Z. biserialis'' |Deformed mass of ovals along a mid-line groove. | |- |}
=== Chordata ===
{| class="wikitable" style="width:70%;" |- !Genus !Species !Notes !Images |- |''Burykhia<ref name="Fedonkin2012"/>'' | *''B. hunti'' |Sac-like organism, possible tunicate. |center|100px |- |}
=== Annelida ===
{| class="wikitable" style="width:70%;" |- !Genus !Species !Notes !Images |- |''Calyptrina<ref name=Sokolov/>'' | *''C. striata'' |Tubular organism. |center|100px |- |}
=== ''incertae sedis'' ===
{| class="wikitable sortable" style="width:70%;" |- !Genus !Species !Notes !Images |- |''Cyclomedusa<ref name=Sokolov/><ref name=Martin/>'' | *''Cyclomedusa'' sp. |Discoid organism. |center|100px |- |''Hiemalora<ref name=Sokolov/><ref name=Martin/>'' | *''Hiemalora'' sp. |Discoid organism, possibly holdfasts of petalonamids. |center|100px |- |''Kimberella<ref name=Fedonkin2007/><ref name=Martin/>'' | *''Kimberella'' sp. |Egg-shaped organism, possible mollusc. |center|100px |- |''Mawsonites<ref name=Martin/>'' | *''M. spriggi'' |Discoid organism. |center|100px |- |''Nimbia<ref name=Sokolov/><ref name=Martin/>'' | *''N. occlusa'' |Discoid organism. |center|100px |- |''Orbisiana<ref name=Sokolov/>'' | *''Orbisiana'' sp. |Palaeopascichnid organism. |center|100px |- |''Palaeopascichnus<ref name=Sokolov/><ref name=Martin/>'' | *''Palaeopascichnus'' sp. |Palaeopascichnid organism. |center|100px |- |''Parvancorina<ref name=Sokolov/><ref name=Martin/>'' | *''P. sagitta'' |Anchor-shaped organism, possible mollusc or arthropod. |center|100px |- |''Solza<ref name=Ivanstov2/>'' | *''S. margarita'' |Egg-shaped organism. | |- |''Harlaniella<ref name="Ivantsov2013">{{cite journal |last1=Ivantsov |first1=A. Yu. |title=New data on Late Vendian problematic fossils from the genus Harlaniella |journal=Stratigraphy and Geological Correlation |date=November 2013 |volume=21 |issue=6 |pages=592–600 |issn=0869-5938 |eissn=1555-6263 |doi=10.1134/S0869593813060051}}</ref>'' | *''Harlaniella'' sp. |Ribbon-like organism. | |- |''Vendotaenid<ref name=Sokolov/>'' | *''Vendotaenid'' |Ribbon-like organisms. |center|100px |- |}
=== Flora ===
{| class="wikitable" style="width:70%;" |- !Genus !Species !Notes !Images |- |style="background:#D1FFCF;" |''Archyfasma<ref name="Leonov">{{cite journal |last1=Leonov |first1=M. V. |title=Macroscopic plant remains from the base of the Ust'-Pinega formation (Upper Vendian of the Arkhangelsk Region) |journal=Paleontological Journal |date=October 2007 |volume=41 |issue=6 |pages=683–691 |doi=10.1134/S0031030107060123}}</ref>'' |style="background:#D1FFCF;" | *''A. dimera'' *''A. lamellata'' |style="background:#D1FFCF;" |Branching macroalgae. |style="background:#D1FFCF;" | |- |style="background:#D1FFCF;" |''Beltanelliformis<ref name=Sokolov/><ref name=Martin/>'' |style="background:#D1FFCF;" | *''Beltaneillformis'' sp. |style="background:#D1FFCF;" |Cyanobacterial colony. |style="background:#D1FFCF;" |center|100px |- |style="background:#D1FFCF;" |''Eoholynia<ref name="Leonov"/>'' |style="background:#D1FFCF;" | *''E. fruticulosa'' |style="background:#D1FFCF;" |Branching macroalgae. |style="background:#D1FFCF;" | |- |style="background:#D1FFCF;" |''Favosiphycus<ref name="Leonov"/>'' |style="background:#D1FFCF;" | *''F. wukii'' |style="background:#D1FFCF;" |Flattened thallus crust-like, consisting of densely packed cells. |style="background:#D1FFCF;" | |- |style="background:#D1FFCF;" |''Gandvikia<ref name="Leonov"/>'' |style="background:#D1FFCF;" | *''G. caudata'' |style="background:#D1FFCF;" |Ribbon-shaped macroalgae. |style="background:#D1FFCF;" | |- |style="background:#D1FFCF;" |''Mezenia<ref name=Sokolov/>'' |style="background:#D1FFCF;" | *''M. kossovoyi'' |style="background:#D1FFCF;" |Sausage shaped macroalgae. |style="background:#D1FFCF;" | |- |style="background:#D1FFCF;" |''Serebrina''<ref name=":0">{{Cite journal|last=Istchenko|first=A. A.|date=1983|title=To the question about stages of development of the algal flora of the South-Western part of Eastern-European platform|journal=Fossil Fauna and Flora of the Ukraine. III Session of the Ukrainian Paleontological Society|pages=70–75}}</ref> |style="background:#D1FFCF;" | *''S. crustacea'' |style="background:#D1FFCF;" |Encrusting macroalgae. |style="background:#D1FFCF;" | |- |}
=== Ichnogenera ===
{| class="wikitable" style="width:70%;" |- !Genus !Species !Notes !Images |- |style="background:#FEF6E4;"|''Epibaion'' |style="background:#FEF6E4;"| *''Epibaion'' sp. |style="background:#FEF6E4;"|Feeding traces of proarticulates. |style="background:#FEF6E4;"|center|100px |- |style="background:#FEF6E4;"|''Kimberichnus<ref>{{cite journal |last1=Ivantsov |first1=A. Yu. |title=Trace fossils of precambrian metazoans “Vendobionta” and “Mollusks” |journal=Stratigraphy and Geological Correlation |date=May 2013 |volume=21 |issue=3 |pages=252–264 |doi=10.1134/S0869593813030039}}</ref><ref name=Martin/>'' |style="background:#FEF6E4;"| *''Kimberichnus'' sp. |style="background:#FEF6E4;"|Feeding traces of ''Kimberella''. |style="background:#FEF6E4;"|center|100px |- |style="background:#FEF6E4;"|''Nenoxites<ref name=Sokolov/>'' |style="background:#FEF6E4;"| *''Nenoxites'' sp. |style="background:#FEF6E4;"|Movement traces. |style="background:#FEF6E4;"|center|100px |- |style="background:#FEF6E4;"|''Neonereites<ref name=Sokolov/>'' |style="background:#FEF6E4;"| *''Neonereites'' sp. |style="background:#FEF6E4;"|Burrows. |style="background:#FEF6E4;"|center|100px |- |style="background:#FEF6E4;"|''Planolites<ref name=Sokolov/>'' |style="background:#FEF6E4;"| *''Planolites'' sp. |style="background:#FEF6E4;"|Burrows. |style="background:#FEF6E4;"|center|100px |- |}
== See also == {{Portal|Geology|Russia|Paleontology}} * List of fossiliferous stratigraphic units in Russia
==References== {{reflist}}
{{Clear}}
{{DEFAULTSORT:Ust' Pinega Formation}} Category:Geology of European Russia Category:Geologic formations of Russia Category:Ediacaran Europe Category:Geography of Arkhangelsk Oblast Category:Long stubs with short prose