0.0–12.5 m
Massive grey limestone with stromatoporoid biostromes; uppermost Pragian.
01
GSSP
Zinzilban Section — GSSP
Lower Devonian · 416.0–397.0 Ma
Overview
The UNESCO-ratified Global Boundary Stratotype Section and Point for the Pragian–Emsian boundary of the Lower Devonian. The signature credential of the Kitab Geopark.
- Period
- Lower Devonian · 416.0–397.0 Ma
Fauna
Tabulate Corals
-
Favosites styriacus, Squameofavosites bohemicus, Pachyfavosites polymorphus
Characteristic Pragian–Emsian boundary assemblage.
Rugose Corals
-
Calceola sandalina, Phacelophyllum kunthi
Brachiopods
-
Howellella mercuri, Eoreticularia magna, Atrypa reticularis
Index brachiopods used to constrain the GSSP boundary.
Trilobites
-
Asteropyge zinzilbanensis, Phacops sp.
Conodonts
-
Polygnathus dehiscens, Polygnathus excavatus
GSSP marker species — first appearance defines the Pragian–Emsian boundary.
Stratigraphy
-
-
12.5–18.0 m
Crinoidal grainstones with abundant brachiopod debris — Pragian–Emsian boundary interval.
-
18.0–31.7 m
Dark argillaceous limestone yielding Polygnathus dehiscens — formal GSSP marker bed.
-
31.7–55.0 m
Bedded limestone with chert nodules; basal Emsian.
Location
- Latitude
- 38.850000
- Longitude
- 66.950000