Terreneuvian

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Baykonur
glaciation
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Orsten Fauna
Archaeocyatha extinction
SSF diversification, first brachiopods & archaeocyatha
Treptichnus pedum trace
Large negative peak δ 13Ccarb excursion
First Cloudina & Namacalathus mineral tubular fossils
Stratigraphic scale of the ICS subdivisions and Precambrian/Cambrian boundary.

Coordinates: 47°04′34″N 55°49′52″W / 47.0762°N 55.8310°W / 47.0762; -55.8310

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. The boundary is defined on the appearance of the complex, vertical trace fossil Treptichnus (formerly Phycodes) pedum.

The Terreneuvian is the lowermost and oldest Series of the Cambrian geological System.[1] Its base is defined by the first appearance datum of the trace fossil Treptichnus pedum around 541.0 ± 1.0 million years ago. Its top is defined as the first appearance of trilobites in the stratigraphic record around ~521 million years ago.[2] This series was formally ratified by the International Commission on Stratigraphy in 2012.[3]

The Fortunian Stage and presently unnamed Cambrian Stage 2 are the Stages within this Series. The Terreneuvian corresponds to the pre-trilobitic Cambrian.[4]

The name Terreneuvian is derived from Terre Nueve, a French name for the island of Newfoundland, Canada, where many rocks of this age are found, including the type section.[1][2]

Type locality[edit]

The type locality (GSSP) of the Terreneuvian is in Fortune Head, at the northern edge of the Burin Peninsula, Newfoundland, Canada (47°04′34″N 55°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.[5]

References[edit]

  1. ^ a b Landing, E., Peng, S., Babcock, L. E., Geyer, G., & Moczydlowska-Vidal, M. (2007). Global standard names for the lowermost Cambrian series and stage. Episodes, 30(4), 287.
  2. ^ a b PENG, S.C. & BABCOCK, L.E. 2011. Continuing progress on chronostratigraphic subdivision of the Cambrian System. Bulletin of Geosciences 86(3), 391–396 (1 figure). Czech Geological Survey, Prague. ISSN 1214-1119.
  3. ^ http://www.stratigraphy.org/column.php?id=Chart/Time%20Scale
  4. ^ Li, G. "The Fad of Watsonella Crosbyi". Retrieved 10 November 2012. 
  5. ^ Brasier, Martin; John Cowie, Michael Taylor (1994). "Decision on the Precambrian-Cambrian boundary stratotype". Episodes 17 (1-2): 95–100. Retrieved 14 September 2012. 

See also[edit]

Preceded by Proterozoic Eon Phanerozoic Eon
Paleozoic Era Mesozoic Era Cenozoic Era
Cambrian Ordovician Silurian Devonian Carboniferous Permian Triassic Jurassic Cretaceous Paleogene Neogene 4ry