GSSP for Carnian Stage
Definition:
The GSSP for the base of the Carnian Stage is defined on the north face of the Cordevole Valley, on the southern slopes of the crest separating the Badia/Abtei and the Cordevole valleys, (46° 31' 37"N, 11° 55' 49"E) at an elevation of 1980 m, approximately 4.7 km south of San Cassiano/St. Kassian in the Dolomites (Southern Alps). The GSSP boundary is located at the base of bed SW4, 45 m above the base of the San Cassiano Fm.
Location:
On the north face of the Cordevole Valley, on the southern slopes of the crest separating the Badia/Abtei and the Cordevole valleys, (46° 31' 37"N, 11° 55' 49"E) at an elevation of 1980 m, approximately 4.7 km south of San Cassiano/St. Kassian in the Dolomites (Southern Alps).
The section consists of hemipelagites and thin turbidite beds (both siliciclastic and carbonate intraclastic), deposited below storm wave-base with a high but variable sediment accumulation rate (San Cassiano Fm.).
Primary Markers:
FAD of the ammonoids Daxatina canadensis (Whiteaves).
Secondary Markers:
FAD of the conodont Paragondolella polygnathiformis (Budurov and Stefanov), appearing 70 cm above the first occurrence of Daxatina canadensis and at the base of a long normal-polarity magnetic zone (S2n) in close proximity to the boundary.
Radiometric Dating:
Stable Carbon Isotopes:Correlation Events:
FAD of the ammonoid Daxatina canadensis; just below FO of conodont Paragondolella polygnathiformis and base of normal-polarity magnetic zone S2n
Other Locations around the World:
Notes on Derivation of Age:
The GSSP is one ammonite subzone just above a level dated at 237.77 ± 0.14 Ma.