World Library  
Flag as Inappropriate
Email this Article

Cambrian Series 2

Article Id: WHEBN0037722334
Reproduction Date:

Title: Cambrian Series 2  
Author: World Heritage Encyclopedia
Language: English
Subject: Cambrian Series 3, Cambrian, Cambrian Stage 4, Archean, Precambrian
Collection: Cambrian, Cambrian Geochronology, Geological Epochs, Stratigraphy
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Cambrian Series 2

Cambrian Series 2 is the unnamed 2nd series of the Cambrian. It lies above the Terreneuvian series and below the Cambrian Series 3. Series 2 has not been formally defined by the International Commission on Stratigraphy, lacking a precise lower and upper 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.[1] The upper boundary is proposed as the first appearance of either the trilobite species Oryctocephalus indicus or Ovatoryctocara granulata, currently estimated to be around ~509 million years ago.[2]

Contents

  • Naming 1
  • Subdivisions 2
  • Biostratigraphy 3
  • References 4

Naming

The International Commission on Stratigraphy has not named the 2nd stage of the Cambrian yet.[1] The new name will replace the older terms "Lower Cambrian" and "Early Cambrian". The nomenclature used in Sibera uses the term "Yakutian" for this series.[3]

Subdivisions

The 2nd series is currently subdivided by the ICS into two stages: Cambrian Stage 3 and Cambrian Stage 4. Both of these stages also lack formal definition.[1] The Siberian nomenclature distinguishes three stages (lowest first): Atdabanian, Botomian and Toyonian.[3] In general most subdivisions of this series rely on biostratigraphy of trilobite zones.[4]

Biostratigraphy

The beginning of the 2nd series of the Cambrian is marked by the appearance of trilobites. Correlating this event on different continents has proven difficult and resolving this is essential for the definition of the lower boundary of this series. Currently the oldest trilobite known is Lemdadella which marks the beginning of the Fallotaspis zone.[4]

The end of the 2nd series of the Cambrian is marked by the first major biotic extinction of the Paleozoic. Changes in ocean chemistry and the marine environment are posited as the most likely cause of these extinctions.[5]

References

  1. ^ a b c "GSSP Table - Paleozoic Era". Retrieved 18 November 2012. 
  2. ^ Gozalo, Rodolfo; Álvarez, María Eugenia Dies; Vintaned, José Antonio Gámez; Zhuravlev, Andrey Yu.; Bauluz, Blanca; Subías, Ignacio; Chirivella Martorell, Juan B.; Mayoral, Eduardo; Gursky, Hans-Jürgen; Andrés, José Antonio; Liñán, Eladio (1 December 2011). "Proposal of a reference section and point for the Cambrian Series 2-3 boundary in the Mediterranean subprovince in Murero (NE Spain) and its intercontinental correlation". Geological Journal: n/a–n/a.  
  3. ^ a b "The 13th International Field Conference of the Cambrian Stage Subdivision Working Group". Episodes 31 (4): 440–441. 
  4. ^ a b Yuan, J.L.; Zhu, X.J.; Lin, J.P.; Zhu, M.Y. (22 September 2011). "Tentative correlation of Cambrian Series 2 between South China and other continents". Bulletin of Geosciences: 397–404.  
  5. ^ Zhang, Wenhao, et al. (2014). "Mass-occurrence of oncoids at the Cambrian Series 2–Series 3 transition: Implications for microbial resurgence following an Early Cambrian extinction". Gondwana Research.  
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.