Guzhangian

28°43′12″N 109°57′53″E / 28.7200°N 109.9647°E / 28.7200; 109.9647 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
~500.5 – ~497 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Chronology
−540 — – −535 — – −530 — – −525 — – −520 — – −515 — – −510 — – −505 — – −500 — – −495 — – −490 — – −485 — – N ♇ P a l e o z o i c Ediacaran C a m b r i a n O T e r r e n e u v i a n S e r i e s 2 M i a o l i n g. F u r o n g. E Fortunian "Stage 2" "Stage 3" "Stage 4" Wuliuan Drumian Guzhangian Paibian Jiangshanian "Stage 10" Tremadocian               ← Orsten Fauna ← Burgess Shale ← Kaili biota ← Archaeocyatha extinction ← Emu Bay Shale ← Sirius Passet biota ← Chengjiang biota ← First Trilobites ← SSF diversification, first brachiopods & archaeocyatha ← First halkieriids, mollusсs, hyoliths SSF ← Baykonurian glaciation ← Dresbachian extinction   Major Glacial period Subdivision of the Cambrian according to the ICS, as of 2022.^[1] Vertical axis scale: millions of years ago
Etymology
Name formality	Formal
Name ratified	2008^[2]
Former name(s)	Cambrian Stage 7
Usage information
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°43′12″N 109°57′53″E / 28.7200°N 109.9647°E / 28.7200; 109.9647
Lower GSSP ratified	2008^[2]
Upper boundary definition	FAD of the Trilobite Glyptagnostus reticulatus
Upper boundary GSSP	Paibi section, Paibi, Hunan, China 28°23′22″N 109°31′33″E / 28.3895°N 109.5257°E / 28.3895; 109.5257
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°43′12″N 109°57′53″E / 28.7200°N 109.9647°E / 28.7200; 109.9647), where Lejopyge laevigata has its first appearance.^[5]

References

1. "Chart/Time Scale". stratigraphy.org. International Commission on Stratigraphy.
2. 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.
3. 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.
4. 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.
5. "GSSP for Guzhangian Stage". Retrieved 12 November 2012.
6. 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.^{[dead link]}