GSSP for Roadian Stage
Definition:
The base of the Guadalupian Series and Roadian Stage is defined at 42.7m above the base of the Cutoff Formation in Stratotype Canyon, Texas, U.S.A. It coincides with the first occurrence of conodont Jinogondolella nankingensis, in the transitional continuum from Mesogondolella idahoensis to Jinogondolella nankingensis.
Location:
The GSSP section is located in the Guadalupe Mountains National Park, Texas, U.S.A. in Stratotype Canyon, at the west face of the southern Guadalupe Mountains at a latitude of 31.8767°N and a longitude of 104.8768°W.
In the GSSP Section the Cutoff Formation comprises the limestone unit of the Shumard Member, the shale and limestone units of the El Centro Member and the limestone unit of the Williams Ranch Member. The GSSP is defined at 42.7m above the base of the Cutoff Formation in the limestone unit of the El Centro Member, 29cm below a prominent shale band
Primary Markers:
The GSSP is at the first occurrence of conodont Jinogondolella nankingensis, in the transitional continuum from Mesogondolella idahoensis to Jinogondolella nankingensis.
Correlation Events:
Conodont FAD Jinogondolella nankingensis
References:
Shen, Shu-zhong, Dong-xun Yuan, Charles M. Henderson, Qiong Wu, Yi-chun Zhang, Hua Zhang, Lin Mu, et al. "Progress, Problems and Prospects: An Overview of the Guadalupian Series of South China and North America." Earth-Science Reviews 211 (December 1, 2020): 103412. DOI: 10.1016/j.earscirev.2020.103412.