Tashkak Fm
Period:
Devonian
Age Interval:
Eifelian, N8
Province:
Nuratau
Type Locality and Naming
Along the Tashkak quarry, South Nuratau Ridge. D.M.Ogarev et al. in 1972 (460, p. 116) in the southwestern part of the Kokcha Mountain.
Synonym: Tashkakskaya Suite, Ташкакская св.
Lithology and Thickness
Dolomites and dolomitic limestones. Thickness more than 350 m.
Lithology Pattern:
Dolomitic limestone
Relationships and Distribution
Lower contact
Boundaries with surrounding formations are tectonic.
Upper contact
Boundaries with surrounding formations are tectonic.
Regional extent
Western end of the South Nuratau Ridge.
GeoJSON
null
Fossils
Crinoids - Hexacrinites cf. tuberosus Yelt.; stromatoporoids - Actinostroma">Actinostroma sp. (ex gr. clathratum Nic.); amphiporoids - Paraamphipora sp. (ex gr. rasilis Yavor.), P. sp. (ex gr. clathratum Nic.) and others.
Age
The Eifelian age is determined by crinoids. Assigned here as base Givetian for graphic purposes ("Eifelian" age is only an estimate from crinoids)
Age Span:
Beginning stage:
Givetian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
385.30
Ending stage:
Givetian
Fraction up in the ending stage:
1.0
Ending date (Ma):
378.90
Depositional setting
Depositional pattern:
Additional Information
Compiler:
V.V.Mikhailov – In: GeoGPT translation of: “Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian)”