Asselian

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Asselian
298.9 ± 0.15 – 293.52 ± 0.17 Ma
Chronology
Etymology
Name formalityFormal
Usage information
Celestial body Earth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unit Age
Stratigraphic unit Stage
Time span formalityFormal
Lower boundary definition FAD of the Conodont Streptognathodus isolatus within the morphotype Streptognathodus wabaunsensis chronocline
Lower boundary GSSP Aidaralash, Ural Mountains, Kazakhstan
50°14′45″N57°53′29″E / 50.2458°N 57.8914°E / 50.2458; 57.8914
Lower GSSP ratified1996 [2]
Upper boundary definitionFAD of the Conodont Mesogondolella monstra
Upper boundary GSSP Usolka section, Southern Urals, Russia.
53°55′29″N56°43′43″E / 53.9247°N 56.7287°E / 53.9247; 56.7287
Upper GSSP ratified2018 [3]

In the geologic timescale, the Asselian is the earliest geochronologic age or lowermost chronostratigraphic stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Asselian lasted between 298.9 and 293.52 million years ago (Ma). It was preceded by the Gzhelian (the latest or uppermost subdivision in the Carboniferous) and followed by the Sakmarian.

Contents

Stratigraphy

The Asselian Stage was introduced into scientific literature in 1954, when the Russian stratigrapher V.E. Ruzhenchev split it off from the Artinskian. At the time, the Artinskian still encompassed most of the lower Permian – its current definitions are more restricted. The Asselian is named after the Assel River in the southern Ural Mountains of Kazakhstan and Bashkortostan. [4]

The base of the Asselian Stage is equivalent to the base of the Cisuralian Series and the Permian System. It is defined as the point in the stratigraphic record where fossils of the conodont Streptognathodus isolatus first appear. The global reference profile for the base (the GSSP or golden spike) is located in the valley of the Aidaralash River, near Aqtöbe in the Ural Mountains of Kazakhstan. [5] Other reference species which approximate the base of the Asselian include Streptognathodus invaginatus and Str. nodulinearis (conodonts) and Sphaeroschwagerina vulgaris and Sph. fusiformis (fusilinids). [5]

The top of the Asselian stage (the base of the Sakmarian stage) is at the first appearance of conodont species Mesogondolella monstra.

Asselian biostratigraphy is mostly defined by the evolution of Streptognathodus. There is some debate over the exact sequence of species; one option, according to Henderson (2018), [6] lists the following biozones, from youngest to oldest:

Regional equivalents

In North America, the regional equivalent of the Asselian is the Nealian stage. The Nealian (lower Wolfcampian) is named after the Neal Ranch Formation in the Glass Mountains of west Texas. [7] [8] In South China, the Asselian is equivalent to at least the lower part of the regional Zisongian stage of the Chuanshanian Series. [9] [10] Both the Nealian and Zisongian are defined by fusilinid assemblages, so their precise correlation to the conodont-based global timescale is uncertain.

The Asselian occupies a portion of major terrestrial sediment units in Europe, namely the Autunian series of France and the lower Rotliegend of Germany. [11] [12] [13]

Notable formations

Related Research Articles

<span class="mw-page-title-main">Permian</span> Sixth and last period of the Paleozoic Era 299–252 million years ago

The Permian is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia.

The Guadalupian is the second and middle series/epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± 0.5 – 259.1 ± 0.4 Mya. The series saw the rise of the therapsids, a minor extinction event called Olson's Extinction and a significant mass extinction called the end-Capitanian extinction event. The Guadalupian was previously known as the Middle Permian.

First appearance datum (FAD) is a term used by geologists and paleontologists to designate the first appearance of a species in the geologic record. FADs are determined by identifying the geologically oldest fossil discovered, to date, of a particular species. A related term is last appearance datum (LAD), the last appearance of a species in the geologic record.

<span class="mw-page-title-main">Cisuralian</span> First series of the Permian

The Cisuralian is the first series/epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan and dates between 298.9 ± 0.15 – 272.3 ± 0.5 Ma.

The Lopingian is the uppermost series/last epoch of the Permian. It is the last epoch of the Paleozoic. The Lopingian was preceded by the Guadalupian and followed by the Early Triassic.

<span class="mw-page-title-main">Anisian</span> Stage of the Triassic

In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from 247.2 million years ago until 242 million years ago. The Anisian Age succeeds the Olenekian Age and precedes the Ladinian Age.

In the geologic timescale, the Artinskian is an age or stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Artinskian likely lasted between 290.1 and 283.5 million years ago (Ma) according to the most recent revision of the International Commission on Stratigraphy (ICS) in 2022. It was preceded by the Sakmarian and followed by the Kungurian.

The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya and 83.6 ± 0.7 mya. The Santonian is preceded by the Coniacian and is followed by the Campanian.

In the geologic timescale, the Sakmarian is an age or stage of the Permian period. It is a subdivision of the Cisuralian Epoch or Series. The Sakmarian lasted between 293.52 and 290.1 million years ago (Ma). It was preceded by the Asselian and followed by the Artinskian.

In the geologic timescale, the Kungurian is an age or stage of the Permian. It is the latest or upper of four subdivisions of the Cisuralian Epoch or Series. The Kungurian lasted between 283.5 and 273.01 million years ago (Ma). It was preceded by the Artinskian and followed by the Roadian.

In the geologic timescale, the Wordian is an age or stage of the Permian. It is the middle of three subdivisions of the Guadalupian Epoch or Series. The Wordian lasted between 266.9 and 264.28 million years ago (Ma). It was preceded by the Roadian and followed by the Capitanian.

<span class="mw-page-title-main">Wuchiapingian</span> Eighth stage of the Permian

In the geologic timescale, the Wuchiapingian or Wujiapingian is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian Epoch or Series. The Wuchiapingian spans the time between 259.51 and 254.14 million years ago (Ma). It was preceded by the Capitanian and followed by the Changhsingian.

In the geologic time scale, the Changhsingian or Changxingian is the latest age or uppermost stage of the Permian. It is also the upper or latest of two subdivisions of the Lopingian Epoch or Series. The Changhsingian lasted from 254.14 to 251.9 million years ago (Ma). It was preceded by the Wuchiapingian and followed by the Induan.

<span class="mw-page-title-main">Ladinian</span> Age in the Middle Triassic

The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between 242 Ma and ~237 Ma. The Ladinian was preceded by the Anisian and succeeded by the Carnian.

<span class="mw-page-title-main">Viséan</span> Second stage of the Carboniferous

The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 346.7 to 330.9 Ma. It follows the Tournaisian age/stage and is followed by the Serpukhovian age/stage.

The Kasimovian is a geochronologic age or chronostratigraphic stage in the ICS geologic timescale. It is the third stage in the Pennsylvanian, lasting from 307 to 303.7 Ma. The Kasimovian Stage follows the Moscovian and is followed by the Gzhelian. The Kasimovian saw an extinction event which occurred around 305 mya, referred to as the Carboniferous Rainforest Collapse. It roughly corresponds to the Missourian in North American geochronology and the Stephanian in western European geochronology.

<span class="mw-page-title-main">Gzhelian</span> Seventh and final stage of the Carboniferous

The Gzhelian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the youngest stage of the Pennsylvanian, the youngest subsystem of the Carboniferous. The Gzhelian lasted from 303.7 to 298.9 Ma. It follows the Kasimovian age/stage and is followed by the Asselian age/stage, the oldest subdivision of the Permian system.

The Norian is a division of the Triassic Period. It has the rank of an age (geochronology) or stage (chronostratigraphy). It lasted from ~227 to 208.5 million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.

Streptognathodus is an extinct genus of conodonts from the Late Carboniferous to Early Permian.

Conodonts are an extinct class of animals whose feeding apparatuses called teeth or elements are common microfossils found in strata dating from the Stage 10 of the Furongian, the fourth and final series of the Cambrian, to the Rhaetian stage of the Late Triassic. These elements can be used alternatively to or in correlation with other types of fossils in the subfield of the stratigraphy named biostratigraphy.

References

  1. ↑ "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
  2. ↑ Davydov, Vladimir; Glenister, Brian; Spinosa, Claude; Ritter, Scott; Chernykh, V.; Wardlaw, B.; Snyder, W. (March 1998). "Proposal of Aidaralash as Global Stratotype Section and Point (GSSP) for base of the Permian System" (PDF). Episodes. 21: 11–18. doi: 10.18814/epiiugs/1998/v21i1/003 . Retrieved 7 December 2020.
  3. ↑ Shen, Shuzhong (August 2018). "Notes from the SPS Chair" (PDF). Permophile: 4. ISSN   1684-5927 . Retrieved 12 December 2020.
  4. ↑ The Nonmarine Permian: Volume 30 of Bulletin of the New Mexico Museum of Natural History and Science, page 48. Editors Spencer G. Lucas, Kate E. Zeigler, 2005
  5. 1 2 Davydov, V.I.; Glenister, B.F.; Spinosa, C.; Ritter, S.M.; Chernykh, V.V.; Wardlaw, B.R. and Snyder, W.S.; 1998: Proposal of Aidaralash as Global Stratotype Section and Point (GSSP) for base of the Permian System, Episodes 21(1): pp 11–18.
  6. ↑ Henderson, Charles M. (2018). "Permian conodont biostratigraphy". Geological Society, London, Special Publications. 450 (1): 119–142. Bibcode:2018GSLSP.450..119H. doi:10.1144/SP450.9. ISSN   0305-8719. S2CID   132523775.
  7. ↑ Ross, Charles A.; Ross, June R.P. (1987). "Biostratigraphic zonation of late Paleozoic depositional sequences". Cushman Foundation for Foraminiferal Research, Spec. Publication. 24.
  8. ↑ Ross, June R.P.; Ross, Charles A. (1997). "Nealian and Lenoxian (Wolfcampian, Lower Permian) Depositional Sequences, Fusulinid Facies and Biostratigraphy, Glass Mountains, Texas". Cushman Foundation for Foraminiferal Research, Special Publication. 36: 125–128.
  9. ↑ Yugan, Jin; Qinghau, Shang; Xiangdong, Wang; Yue, Wang; Jinzhang, Sheng (1999). "Chronostratigraphic Subdivision and Correlation of the Permian in China". Acta Geologica Sinica - English Edition. 73 (2): 127–138. doi:10.1111/j.1755-6724.1999.tb00820.x. S2CID   130794861.
  10. ↑ Shen, Shuzhong; Zhang, Hua; Zhang, Yichun; Yuan, Dongxun; Chen, Bo; He, Weihong; Mu, Lin; Lin, Wei; Wang, Wenqian; Chen, Jun; Wu, Qiong; Cao, Changqun; Wang, Yue; Wang, Xiangdong (2019). "Permian integrative stratigraphy and timescale of China". Science China Earth Sciences. 62 (1): 154–188. Bibcode:2019ScChD..62..154S. doi:10.1007/s11430-017-9228-4. ISSN   1674-7313. S2CID   134488821.
  11. ↑ Pellenard, Pierre; Gand, Georges; Schmitz, Mark; Galtier, Jean; Broutin, Jean; Stéyer, Jean-Sébastien (2017). "High-precision U-Pb zircon ages for explosive volcanism calibrating the NW European continental Autunian stratotype". Gondwana Research. 51: 118–136. Bibcode:2017GondR..51..118P. doi:10.1016/j.gr.2017.07.014.
  12. ↑ Schneider, Joerg W.; Lucas, Spencer G.; Scholze, Frank; Voigt, Sebastian; Marchetti, Lorenzo; Klein, Hendrik; Opluštil, Stanislav; Werneburg, Ralf; Golubev, Valeriy K.; Barrick, James E.; Nemyrovska, Tamara; Ronchi, Ausonio; Day, Michael O.; Silantiev, Vladimir V.; Rößler, Ronny (2020). "Late Paleozoic–early Mesozoic continental biostratigraphy — Links to the Standard Global Chronostratigraphic Scale". Palaeoworld. 29 (2): 186–238. doi:10.1016/j.palwor.2019.09.001. S2CID   210316208.
  13. ↑ Schneider, Joerg W.; Scholze, Frank; Ross, Andrew J.; Blake, Bascombe M.; Lucas, Spencer G. (2022). "Improved blattoid insect and conchostracan zonation for the Late Carboniferous, Pennsylvanian, of Euramerica". Geological Society, London, Special Publications. 512 (1): 865–891. Bibcode:2022GSLSP.512..865S. doi:10.1144/SP512-2021-93. ISSN   0305-8719. S2CID   238645303.
  14. ↑ Schneider, Jörg W.; Lucas, Spencer G.; Barrick, James E. (2013). "The Early Permian age of the Dunkard Group, Appalachian basin, U.S.A., based on spiloblattinid insect biostratigraphy". International Journal of Coal Geology. 119: 88–92. Bibcode:2013IJCG..119...88S. doi:10.1016/j.coal.2013.07.019. ISSN   0166-5162.

50°14′45″N57°53′29″E / 50.2458°N 57.8914°E / 50.2458; 57.8914

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