Shirgesht Fm
Period:
Cambrian, Ordovician
Age Interval:
Cambrian Stage 10 – Darriwilian, Ir2
Province:
Iran
Lithology and Thickness
Thickness of ~1200m. Flaggy, nodular dolomitic limestone with marl intercalations in the lower sections. The middle part consists of red-brown sandy fossiliferous sandstone, and the lower is mostly greenish grey siltstone and shales.
Lithology Pattern:
Dolomitic limestone
Relationships and Distribution
Lower contact
Regionally, the schematic strat column indicates the next older unit as Derenjal Fm
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Niur Fm (Gushkamar Gr)
Regional extent
GeoJSON
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Fossils
Age
Cambrian Stage 10 – Darriwilian
Age Span:
Beginning stage:
Cambrian Stage 10
Fraction up in beginning stage:
0.9
Beginning date (Ma):
487.27
Ending stage:
Darriwilian
Fraction up in the ending stage:
0.75
Ending date (Ma):
460.99
Depositional setting
Depositional pattern:
Additional Information
Compiler:
Middle East Geological Timescale 2008 Al-Husseini, Journal of Middle East Petroleum Geosciences v 13, no. 4