Cenomanian

Last updated
Cenomanian
100.5 – 93.9 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 Planktonic Foraminifer Rotalipora globotruncanoides
Lower boundary GSSP Mont Risoux, Hautes-Alpes, France
44°23′33″N5°30′43″E / 44.3925°N 5.5119°E / 44.3925; 5.5119
Lower GSSP ratified2002 [2]
Upper boundary definitionFAD of the Ammonite Watinoceras devonense
Upper boundary GSSP Rock Canyon, Colorado, US
38°16′56″N104°43′39″W / 38.2822°N 104.7275°W / 38.2822; -104.7275
Upper GSSP ratifiedSeptember 2003 [3]

The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. [4] An age is a unit of geochronology; it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name.

Contents

As a unit of geologic time measure, the Cenomanian Age spans the time between [5] 100.5 and 93.9 million years ago (Mya). In the geologic timescale, it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts around at 95 Mya.[ citation needed ]

The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States.

At the end of the Cenomanian, an anoxic event took place, called the Cenomanian-Turonian boundary event or the "Bonarelli event", that is associated with a minor extinction event for marine species.

Cenomanithrips , an extinct thrip of the Stenurothripidae family, was named after the Cenomanian, the age of the Myanmar amber in which it was discovered. [6]

Stratigraphic definitions

The Cenomanian was introduced in scientific literature by French palaeontologist Alcide d'Orbigny in 1847. Its name comes from the Neo-Latin name of the French city of Le Mans (département Sarthe), Cenomanum. The base of the Cenomanian Stage (which is also the base of the Upper Cretaceous Series) is placed at the first appearance of foram species Rotalipora globotruncanoides in the stratigraphic record. An official reference profile for the base of the Cenomanian (a GSSP) is located in an outcrop at the western flank of Mont Risou, near the village of Rosans in the French Alps (département Hautes-Alpes, coordinates: 44°23'33"N, 5°30'43"E). The base is, in the reference profile, located 36 meters below the top of the Marnes Bleues Formation. [7]

The top of the Cenomanian (the base of the Turonian) is at the first appearance of ammonite species Watinoceras devonense .

Important index fossils for the Cenomanian are the ammonites Calycoceras naviculare , Acanthoceras rhotomagense , and Mantelliceras mantelli .

Sequence stratigraphy and palaeoclimatology

The late Cenomanian represents the highest mean sea level observed in the Phanerozoic eon, the past 600 million years (about 150 meters above present-day sea levels). A corollary is that the highlands were at all time lows, so the landscape on Earth was one of warm broad shallow seas inundating low-lying land areas on the precursors to today's continents. What few lands rose above the waves were made of old mountains and hills, upland plateaus, all much weathered. Tectonic mountain building was minimal and most continents were isolated by large stretches of water. Without highlands to break winds, the climate would have been windy and waves large, adding to the weathering and fast rate of sediment deposition.[ citation needed ]

Related Research Articles

The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 184.2 Ma and 174.7 ±0.8 Ma. It follows the Pliensbachian and is followed by the Aalenian.

<span class="mw-page-title-main">Aalenian</span> First age of the Middle Jurassic

The Aalenian is a subdivision of the Middle Jurassic Epoch/Series of the geologic timescale that extends from about 174.7 ±0.8 Ma to about 170.9 ±0.8 Ma. It was preceded by the Toarcian and succeeded by the Bajocian.

The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma. The Albian is preceded by the Aptian and followed by the Cenomanian.

<span class="mw-page-title-main">Aptian</span> Fifth age of the Early Cretaceous

The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma, approximately. The Aptian succeeds the Barremian and precedes the Albian, all part of the Lower/Early Cretaceous.

In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.9 ±0.8 Ma to around 168.2 ±1.2 Ma. The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age.

In the geologic timescale the Bathonian is an age and stage of the Middle Jurassic. It lasted from approximately 168.2 ±1.2 Ma to around 165.3 ±1.1 Ma. The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age.

In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.6 ± 2.0 Ma. The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretaceous and precedes the Hauterivian Stage of the Lower Cretaceous.

The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian spans the time from 83.6 to 72.1 million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian.

The Thanetian is, in the ICS Geologic timescale, the latest age or uppermost stratigraphic stage of the Paleocene Epoch or Series. It spans the time between 59.2 and56 Ma. The Thanetian is preceded by the Selandian Age and followed by the Ypresian Age. The Thanetian is sometimes referred to as the Late Paleocene.

The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene Epoch or Series. It spans the time between 37.71 and33.9 Ma. The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage of the Oligocene.

The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous Epoch or a stage in the Lower Cretaceous Series. It spans the time between 132.6 ± 2 Ma and 125.77. The Hauterivian is preceded by the Valanginian and succeeded by the Barremian.

<span class="mw-page-title-main">Turonian</span> Second age of the Late Cretaceous epoch

The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma. The Turonian is preceded by the Cenomanian Stage and underlies the Coniacian Stage.

The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma. The Coniacian is preceded by the Turonian and followed by the Santonian.

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.

The Hettangian is the earliest age and lowest stage of the Jurassic Period of the geologic timescale. It spans the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma. The Hettangian follows the Rhaetian and is followed by the Sinemurian.

<span class="mw-page-title-main">Sinemurian</span> Second age of the Early Jurassic

In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.5 ±0.3 Ma and 192.9 ±0.3 Ma. The Sinemurian is preceded by the Hettangian and is followed by the Pliensbachian.

The Pliensbachian is an age of the geologic timescale and stage in the stratigraphic column. It is part of the Early or Lower Jurassic Epoch or Series and spans the time between 192.9 ±0.3 Ma and 184.2 ±0.3 Ma. The Pliensbachian is preceded by the Sinemurian and followed by the Toarcian.

<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">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.

References

  1. ↑ International Commission on Stratigraphy. "ICS - Chart/Time Scale". www.stratigraphy.org.
  2. ↑ Kennedy, W.; Gale, A.; Lees, J.; Caron, M. (March 2004). "The Global Boundary Stratotype Section and Point (GSSP) for the base of the Cenomanian Stage, Mont Risou, Hautes-Alpes, France" (PDF). Episodes. 27: 21–32. doi:10.18814/epiiugs/2004/v27i1/003 . Retrieved 13 December 2020.
  3. ↑ Kennedy, W. J.; I. Walaszczyk; W. A. Cobban (2005). "The Global Boundary Stratotype Section and Point for the base of the Turonian Stage of the Cretaceous: Pueblo, Colorado, U.S.A." (PDF). Episodes. 28 (2): 93–104. doi: 10.18814/epiiugs/2005/v28i2/003 .
  4. ↑ See for a detailed geologic timescale Gradstein et al. (2004)
  5. ↑ "International Stratigraphic Chart v2021/05". Archived from the original on 2021-06-05. Retrieved 2021-07-29.
  6. ↑ Tong T, Shih CK, Ren D (2019). "A new genus and species of Stenurothripidae (Insecta: Thysanoptera: Terebrantia) from mid-Cretaceous Myanmar amber". Cretaceous Research. 100: 184–191. doi:10.1016/j.cretres.2019.03.005.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  7. ↑ The GSSP for the Cenomanian was established by Kennedy et al. (2004)

Further reading

44°23′33″N5°30′43″E / 44.39250°N 5.51194°E / 44.39250; 5.51194

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