Terreneuvian

Last updated
Terreneuvian
538.8 ± 0.2 – ~521 Ma
Fortune Head GSSP, Newfoundland.jpg
Delegates from the Ichnia 2012 conference inspect the Global Boundary Stratotype Section and Point (GSSP) for the Ediacaran-Cambrian boundary at Fortune Head Ecological Reserve, Newfoundland, Canada.
Chronology
Etymology
Name formalityFormal
Name ratified2007 [2]
Former name(s)Cambrian Stage 1
Usage information
Celestial body Earth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unit Age
Stratigraphic unit Stage
First proposed by Ed Landing, 2007 [3]
Time span formalityFormal
Lower boundary definitionAppearance of the Ichnofossil Treptichnus pedum
Lower boundary GSSP Fortune Head section, Newfoundland, Canada
47°04′20″N55°51′52″W / 47.072163°N 55.864398°W / 47.072163; -55.864398
Lower GSSP ratified2007 (as base of Terreneuvian and Fortunian) [2]
Upper boundary definitionNot formally defined
Upper boundary definition candidates FAD of Trilobites
Upper boundary GSSP candidate section(s)None

The Terreneuvian is the lowermost and oldest series of the Cambrian geological system. [2] Its base is defined by the first appearance datum of the trace fossil Treptichnus pedum around 538.8 million years ago. Its top is defined as the first appearance of trilobites in the stratigraphic record around 521 million years ago. [4] This series' name was formally accepted by the International Commission on Stratigraphy in 2007. [2]

Contents

The Fortunian stage and presently unnamed Cambrian Stage 2 are the stages within this series. The Terreneuvian corresponds to the pre-trilobitic Cambrian. [5]

The name Terreneuvian is derived from Terre Neuve, the French name for the island of Newfoundland, Canada, where many rocks of this age are found, including the type section. [2] [4]

GSSP

The type locality (GSSP) of the Terreneuvian is in Fortune Head, at the northern edge of the Burin Peninsula, Newfoundland, Canada ( 47°04′34″N55°49′52″W / 47.0762°N 55.8310°W / 47.0762; -55.8310 ). The outcrops show a carbonate-siliciclastic succession which is mapped as the Chapel Island Formation. The formation is divided into the following members that are composed of peritidal sandstones and shales (Member 1), muddy deltaic and shelf sandstones and mudstones (Member 2A), laminated siltstones (Member 2B and 3) and mudstones and limestones of the inner shelf (Member 4). The Precambrian-Cambrian boundary lies 2.4 m above the base of the second member, which is the lowest occurrence of Treptichnus pedum . The traces can be seen on the lower surface of the sandstone layers. The first calcareous shelled skeletal fossils (Ladatheca cylindrica) are 400 m above the boundary. The first trilobites appear 1400 m above the boundary, which corresponds to the beginning of the Branchian Series (Series 2). [6]

Major events

The second phase of the Cambrian explosion occurs during the Terreneuvian. Lots of lophotrochozoan and calcified basal metazoan lineages appeared in this epoch. However, deuterostomes are absent in this interval. [7]

See also

Related Research Articles

<span class="mw-page-title-main">Cambrian</span> First period of the Paleozoic Era, 539–485 million years ago

The Cambrian is the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran period 538.8 million years ago (mya) to the beginning of the Ordovician period 485.4 mya. Its subdivisions, and its base, are somewhat in flux.

<span class="mw-page-title-main">Ediacaran</span> Third and last period of the Neoproterozoic Era

The Ediacaran is a geological period of the Neoproterozoic era that spans 96 million years from the end of the Cryogenian period at 635 Mya to the beginning of the Cambrian period at 538.8 Mya. It is the last period of the Proterozoic eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian period marks the start of the Phanerozoic eon, where recognizable fossil evidence of life becomes common.

<span class="mw-page-title-main">Global Boundary Stratotype Section and Point</span> Boundary of a stage on the geologic time scale

A Global Boundary Stratotype Section and Point (GSSP) is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. The effort to define GSSPs is conducted by the International Commission on Stratigraphy, a part of the International Union of Geological Sciences. Most, but not all, GSSPs are based on paleontological changes. Hence GSSPs are usually described in terms of transitions between different faunal stages, though far more faunal stages have been described than GSSPs. The GSSP definition effort commenced in 1977. As of 2023, 79 of the 101 stages that need a GSSP have a ratified GSSP.

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The Furongian is the fourth and final epoch and series of the Cambrian. It lasted from 497 to 485.4 million years ago. It succeeds the Miaolingian series of the Cambrian and precedes the Lower Ordovician Tremadocian Stage. It is subdivided into three stages: the Paibian, Jiangshanian and the unnamed 10th stage of the Cambrian.

<i>Treptichnus</i> Preserved burrow of an animal

Treptichnus is the preserved burrow of an animal. As such, it is regarded as the earliest widespread complex trace fossil. Its earliest appearance, around 542 mya, which was contemporaneous with the last of the Ediacaran biota, is used to help define the dividing line, considered geologically at 541 mya, between the Ediacaran and Cambrian periods. It is last seen in the fossil record during the Cenomanian.

The Paibian is the lowest stage of Furongian series of the Cambrian. It follows the Guzhangian and is succeeded by the Jiangshanian Stage. The base is defined as the first appearance of the trilobite Glyptagnostus reticulatus around 497 million years ago. The top, or the base of the Jiangshanian is defined as the first appearance of the trilobite Agnostotes orientalis around 494 million years ago.

Lemdadella is an extinct genus of redlichiid trilobites that lived during the late Atdabanian stage, which lasted from 521 to 514 million years ago during the early part of the Cambrian Period.

<span class="mw-page-title-main">Stratigraphy of the Cambrian</span>

The Stratigraphy of the Cambrian period currently has several schemes used for ordering geologic formations from the period. The International Commission on Stratigraphy−ICS scheme has set a stratotype section for the base of the Cambrian, dated quite accurately to 538.8 ± 0.2 million years ago. Russian and Chinese scientists have developed a different scheme.

<span class="mw-page-title-main">Fortunian</span>

The Fortunian age marks the beginning of the Phanerozoic Eon, the Paleozoic Era, and the Cambrian Period. It is the first of the two stages of the Terreneuvian series. Its base is defined as the first appearance of the trace fossil Treptichnus pedum 538.8 million years ago. The top of the Fortunian which is the base of the Stage 2 of the Cambrian has not been formally defined yet, but will correspond to the appearance of an Archeocyatha species or "Small shelly fossils" approximately 529 million years ago.

<span class="mw-page-title-main">Chapel Island Formation</span> Sedimentary formation in the Burin Peninsula, Newfoundland, Canada

The Chapel Island Formation is a sedimentary formation from the Burin Peninsula, Newfoundland, Canada. It is a succession of siliciclastic deposits, over 1,000 metres (3,300 ft) thick, that were deposited during the latest Ediacaran and earliest Cambrian.

Stage 2 of the Cambrian is the unnamed upper stage of the Terreneuvian Series. It lies atop the Fortunian and below Stage 3 of the Cambrian. It is commonly referred to as the Tommotian, after the Cambrian stratigraphy of Siberia. Neither the upper nor lower boundary has yet been defined by the International Commission on Stratigraphy. The preferred definitions for the lower boundary are the first appearance of the molluscs Watsonella crosbyi or Aldanella attleborensis around 529 million years ago. The correlation between the lowest occurrences of A. attleborensis and W. crosbyi with the Zhujiaqing positive carbon isotope excursion (ZHUCE) has led to the conclusion that the combination of these two markers are a reliable indicator of the boundary between the Fortunian and Stage 2. The proposed upper boundary might be the first appearance of trilobites around 521 million years ago.

The Guzhangian is an uppermost stage of the Miaolingian Series of the Cambrian. It follows the Drumian Stage and precedes the Paibian Stage of the Furongian Series. The base is defined as the first appearance of the trilobite Lejopyge laevigata around 500.5 million years ago. The Guzhangian-Paibian boundary is marked by the first appearance of the trilobite Glyptagnostus reticulatus around 497 million years ago.

The Drumian is a stage of the Miaolingian Series of the Cambrian. It succeeds the Wuliuan and precedes the Guzhangian. The base is defined as the first appearance of the trilobite Ptychagnostus atavus around 504.5 million years ago. The top is defined as the first appearance of another trilobite Lejopyge laevigata around 500.5 million years ago.

The Wuliuan stage is the fifth stage of the Cambrian, and the first stage of the Miaolingian Series of the Cambrian. It was formally defined by the International Commission on Stratigraphy in 2018. Its base is defined by the first appearance of the trilobite species Oryctocephalus indicus; it ends with the beginning of the Drumian Stage, marked by the first appearance of the trilobite Ptychagnostus atavus around 504.5 million years ago.

Stage 10 of the Cambrian is the still unnamed third and final stage of the Furongian series. It follows the Jiangshanian and precedes the Ordovician Tremadocian Stage. The proposed lower boundary is the first appearance of the trilobite Lotagnostus americanus around 489.5 million years ago, but other fossils are also being discussed. The upper boundary is defined as the appearance of the conodont Iapetognathus fluctivagus which marks the beginning of the Tremadocian and is radiometrically dated as 485.4 million years ago.

The Miaolingian is the third Series of the Cambrian Period, and was formally named in 2018. It lasted from about 509 to 497 million years ago and is divided in ascending order into 3 stages: the Wuliuan, Drumian, and Guzhangian. The Miaolingian is preceded by the unnamed Cambrian Series 2 and succeeded by the Furongian series.

Cambrian Stage 3 is the still unnamed third stage of the Cambrian. It succeeds Cambrian Stage 2 and precedes Cambrian Stage 4, although neither its base nor top have been formally defined. The plan is for its lower boundary to correspond approximately to the first appearance of trilobites, about 521 million years ago, though the globally asynchronous appearance of trilobites warrants the use of a separate, globally synchronous marker to define the base. The upper boundary and beginning of Cambrian Stage 4 is informally defined as the first appearance of the trilobite genera Olenellus or Redlichia around 514 million years ago.

Cambrian Stage 4 is the still unnamed fourth stage of the Cambrian and the upper stage of Cambrian Series 2. It follows Cambrian Stage 3 and lies below the Wuliuan. The lower boundary has not been formally defined by the International Commission on Stratigraphy. One proposal is the first appearance of two trilobite genera, Olenellus or Redlichia. Another proposal is the first appearance of the trilobite species Arthricocephalus chauveaui. Both proposals will set the lower boundary close to 514 million years ago. The upper boundary corresponds to the beginning of the Wuliuan.

Cambrian Series 2 is the unnamed 2nd series of the Cambrian. It lies above the Terreneuvian series and below the Miaolingian. Series 2 has not been formally defined by the International Commission on Stratigraphy, lacking a precise lower boundary and subdivision into stages. The proposed lower boundary is the first appearance of trilobites which is estimated to be around 521 million years ago.

References

  1. ↑ "Chart/Time Scale". stratigraphy.org. International Commission on Stratigraphy.
  2. 1 2 3 4 5 Landing, Ed; Peng, Shanchi; Babcock, Loren; Geyer, Gerd; Moczydlowska-Vidal, Malgorzata (December 2007). "Global standard names for the Lowermost Cambrian Series and Stage". Episodes. 30 (4): 287–289. doi: 10.18814/epiiugs/2007/v30i4/004 . Retrieved 2024-03-31.
  3. ↑ "GSSPs - The Cambrian System 2019". International Commission on Stratigraphy. Archived from the original on 2023-07-21. Retrieved 2024-03-31.
  4. 1 2 Shan-Chi Peng, Babcock Loren (2011). "Continuing progress on chronostratigraphic subdivision of the Cambrian System" (PDF). Bulletin of Geosciences. 86 (3): 391–396. doi:10.3140/bull.geosci.1273. ISSN   1214-1119. Archived from the original (PDF) on 2023-07-16.
  5. ↑ Li, G. "The Fad of Watsonella Crosbyi". Archived from the original on 2017-01-16.
  6. ↑ Brasier, Martin; John Cowie; Michael Taylor (1994). "Decision on the Precambrian-Cambrian boundary stratotype" (PDF). Episodes. 17 (1–2): 95–100. Archived (PDF) from the original on 2023-06-20. Retrieved 2024-03-31.
  7. ↑ Degan Shu, Yukio Isozaki, Xingliang Zhang, Jan Han, Shigenori Maruyama (2014). "Birth and early evolution of metazoans". Gondwana Research . 25 (3): 884—895. doi:10.1016/j.gr.2013.09.001.{{cite journal}}: CS1 maint: multiple names: authors list (link)


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