Koshbulak Fm
Period:
Jurassic
Age Interval:
Middle Jurassic (Callovian), F1
Province:
Fergana
Type Locality and Naming
Along the river Koshbulak, Fergana ridge. V.N. Ognev, 1946 (336, p.43). Renamed (383, table 5, p. 2 and 3) to the Balabansay Fm.
Synonym: Koshbuulak Suite, Кошбулакская св.
Lithology and Thickness
At the bottom, sandstones, at the top, siltstone (aleurolites) and clays of green and red colors. Thickness 130-260m.
Lithology Pattern:
Sandy_claystone
Relationships and Distribution
Lower contact
Transgressively overlies the Zindan Fmor the Paleozoic,
Upper contact
Unconformably overlain by the lower Cretaceous. E.A. Repman". Str. sl. (446).
Regional extent
Western foothills of the Fergana ridge.
GeoJSON
null
Fossils
Rare plant remains
Age
Conditionally dated to the Callovian.
Age Span:
Beginning stage:
Callovian
Fraction up in beginning stage:
0.2
Beginning date (Ma):
164.54
Ending stage:
Callovian
Fraction up in the ending stage:
1.0
Ending date (Ma):
161.53
Depositional setting
Depositional pattern:
Additional Information
Compiler:
– In: GeoGPT translation of: ”Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian)"