Koltchak Fm
Period:
Jurassic
Age Interval:
Middle Kimmeridgian (J3), Sar1
Province:
East Tajik (easternmost Pamir)
Type Locality and Naming
Includes in Sarykoln district (Istyk type section (Kuntei area)
Synonym: Koltchak suite
Reference section:
Lithology and Thickness
It is composed of light massive and giant-bedded reef limestones.
Lithology Pattern:
Reef limestone
Relationships and Distribution
Lower contact
Schematic stratigraphic column indicates the lower contact as Kutatyr Fm
Upper contact
Schematic stratigraphic column indicates the upper contact as Akkai Fm
Regional extent
Kunteisk area, in the basin of the Kuntei River.
GeoJSON
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Fossils
It contains numerous remains of corals: Stylosmilia corallina Koby, S. michelini M. Edw. et Haime, Enallhelia corallina d'Orb., Intersmilia sp., Thecosmilia sp., and in the top - remains of ammonites, representatives of the genus Hecticoceras of Middle Kimmeridgian type.
Age
The fossil data indicates Middle Kimmeridgian
Age Span:
Beginning stage:
Kimmeridgian
Fraction up in beginning stage:
0.3
Beginning date (Ma):
153.12
Ending stage:
Kimmeridgian
Fraction up in the ending stage:
0.5
Ending date (Ma):
152.01
Depositional setting
Depositional pattern:
Additional Information
Compiler:
Extracted from Baratov, R. B. (1976). Subdivisions of stratified and intrusive rocks of Tajikistan. Donish, Dushanbe, 276.