Guzhangian
28.7200°N 109.9647°E 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.[5]
Guzhangian | ||||||||||||||||||||||||||||||||||||||
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Name formality | Formal | |||||||||||||||||||||||||||||||||||||
Name ratified | 2008[2] | |||||||||||||||||||||||||||||||||||||
Former name(s) | Cambrian Stage 7 | |||||||||||||||||||||||||||||||||||||
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Celestial body | Earth | |||||||||||||||||||||||||||||||||||||
Regional usage | Global (ICS) | |||||||||||||||||||||||||||||||||||||
Time scale(s) used | ICS Time Scale | |||||||||||||||||||||||||||||||||||||
Definition | ||||||||||||||||||||||||||||||||||||||
Chronological unit | Age | |||||||||||||||||||||||||||||||||||||
Stratigraphic unit | Stage | |||||||||||||||||||||||||||||||||||||
First proposed by | Shanchi et al., 2007[3] | |||||||||||||||||||||||||||||||||||||
Time span formality | Formal | |||||||||||||||||||||||||||||||||||||
Lower boundary definition | FAD of the Trilobite Lejopyge laevigata | |||||||||||||||||||||||||||||||||||||
Lower boundary GSSP | Luoyixi section, Luoyixi, Guzhang, Hunan, China 28.7200°N 109.9647°E | |||||||||||||||||||||||||||||||||||||
Lower GSSP ratified | 2008[2] | |||||||||||||||||||||||||||||||||||||
Upper boundary definition | FAD of the Trilobite Glyptagnostus reticulatus | |||||||||||||||||||||||||||||||||||||
Upper boundary GSSP | Paibi section, Paibi, Hunan, China 28.3895°N 109.5257°E | |||||||||||||||||||||||||||||||||||||
Upper GSSP ratified | 2003[4] |
The name Guzhangian is derived from Guzhang County, Hunan Province, China.
The GSSP is defined in the Huaqiao Formation in Hunan.[6] The precise base of the Guzhangian is a limestone layer 121.3 m above the base Huaqiao Formation(花桥组) at the Louyixi section (28.7200°N 109.9647°E), where Lejopyge laevigata has its first appearance.[5]
References
- "Chart/Time Scale". stratigraphy.org. International Commission on Stratigraphy.
- Peng, Shanchi; Babcock, Loren; Zuo, Jingxun; Lin, Huanling; Zhu, Xuejian; Yang, Xianfeng; Robison, Richard; Qi, Yuping; Bagnoli, Gabriella; Chen, Yong’an (March 2009). "The Global Boundary Stratotype Section and Point (GSSP) of the Guzhangian Stage (Cambrian) in the Wuling Mountains, Northwestern Hunan, China". Episodes. 32 (1): 41–55. doi:10.18814/epiiugs/2009/v32i1/006. Retrieved 13 December 2020.
- Shanchi, Peng; Babcock, Loren; Jingxun, Zuo; Huanling, Lin; Xuejian, Zhu; Xianfeng, Yang; Robison, Richard; Yuping, Qi; Bagnoli, Gabriella; Yong’an, Chen. "PROPOSED GLOBAL STANDARD STRATOTYPE-SECTION AND POINT FOR THE GUZHANGIAN STAGE (CAMBRIAN)". International Subcommission on Cretaceous Stratigraphy. International Subcommission on Cambrian Stratigraphy. Retrieved 13 December 2020.
- Peng, S. C.; Babcock, L. E.; Robison, R. A.; Lin, H. L.; Rees, M. N.; Saltzman, M. R. (2004). "Global Standard Stratotype-Section and Point (GSSP) of the Furongian Series and Paibian Stage (Cambrian)". Lethaia. 37 (4): 365–379. doi:10.1080/00241160410002081. Retrieved 8 December 2020.
- "GSSP for Guzhangian Stage". Retrieved 12 November 2012.
- Peng, Shanchi; Loren E. Babcok; Jingxun Zuo; Huanling LIn; Xuejian Zhu; Xianfeng Yang; Richard A. Robison; Yuping Qui; Gabriella Bagnoli; Yong'an Chen (2009). "The Global Boundary Stratotype Section and Point (GSSP) of the Guzhangian Stage (Cambrian) in the Wuling Mountains, Northwestern Hunan, China" (PDF). Episodes. 32 (1): 41–55. doi:10.18814/epiiugs/2009/v32i1/006. Retrieved 14 September 2012.