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.

References:

Mietto, P., Manfrin, S., Preto, N., et al., 2012. The Global Boundary Stratotype Section and Point (GSSP) of the Carnian Stage (Late Triassic) at Prati Di Stuores/Stuores Wiesen Section (Southern Alps, NE Italy). Episodes, 35(3): 414-430.