Name formalityFormal
Name ratified2006[2]
Former name(s)Cambrian Stage 6
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Chronological unitAge
Stratigraphic unitStage
First proposed byBabcock et al., 2006[3]
Time span formalityFormal
Lower boundary definitionFAD of the Trilobite Ptychagnostus atavus
Lower boundary GSSPDrumian section, Wheeler Shale, Utah, U.S.A.
39°30′42″N 112°59′29″W / 39.5117°N 112.9915°W / 39.5117; -112.9915
Lower GSSP ratified2006[2]
Upper boundary definitionFAD of the Trilobite Lejopyge laevigata
Upper boundary GSSPLuoyixi section, Luoyixi, Guzhang, Hunan, China
28°43′12″N 109°57′53″E / 28.7200°N 109.9647°E / 28.7200; 109.9647
Upper GSSP ratified2008[4]

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 GSSP is defined in the Drumian section (39°30′42″N 112°59′29″W / 39.5117°N 112.9915°W / 39.5117; -112.9915) in the Drum Mountains, Millard County, Utah, United States.[5] The stage was also named after the Drum Mountains. The section is an outcrop of the Wheeler Formation, a succession of calcareous shales. The precise base of the Drumian is a laminated limestone 62 m (203 ft) above the base of the Wheeler Formation.[6]

  1. ^ "Chart/Time Scale". stratigraphy.org. International Commission on Stratigraphy.
  2. ^ a b Babcock, Loren; Robison, Richard; Rees, Margaret; Peng, Shanchi; Saltzman, Matthew (June 2007). "The Global boundary Stratotype Section and Point (GSSP) of the Drumian Stage (Cambrian) in the Drum Mountains, Utah, USA". Episodes. 30 (2): 85–89. doi:10.18814/epiiugs/2007/v30i2/003. Retrieved 13 December 2020.
  3. ^ Babcock, Loren; Robinson, Richard; Rees, Margaret; Shanchi, Peng; Saltzman, Matthew. "PROPOSED GLOBAL STANDARD STRATOTYPE-SECTION AND POINT FOR THE DRUMIAN STAGE (CAMBRIAN)". International Subcommission on Cretaceous Stratigraphy. International Subcommission on Cambrian Stratigraphy. Retrieved 13 December 2020.
  4. ^ 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.
  5. ^ Babcock, Loren E.; Richard A. Robison; Margaret N. Rees; Shanchi Peng; Matthew R. Saltzman (2007). "The Global boundary Stratotype Section and Point (GSSP) of the Drumian Stage (Cambrian) in the Drum Mountains, Utah, USA" (PDF). Episodes. 30 (2): 85–95. doi:10.18814/epiiugs/2007/v30i2/003. Retrieved 14 September 2012.[permanent dead link]
  6. ^ "GSSP for Drumian Stage". Retrieved 12 November 2012.

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