Isfara Fm
Type Locality and Naming
Along the Isfara Mountains, Fergana. O.S. Vyalov, 1935 (155, pp. 278-281). Stratotype in the area of the Isfara Mountains, Fergana Depression.
Synonym: Isfarinskaya Suite, Исфаринская св.
Lithology and Thickness
Opokoid clays, siliceous, gray, light-brown, fragmental with large calcareous concretions. Thickness up to 70m.
Relationships and Distribution
Lower contact
Conformably overlain by the Khanabad Fm.
Upper contact
Conformably overlies the Rishtan Fm or the Nefteabad Fm, or with erosion on the Subashin Fm
Regional extent
Along the Isfara Mountains, Fergana. Forms the lower part of the Kushanskoye Horizon. Correlated with the middle part of the Apatak Fm (layers with Ostrea plicata, Aralocardia eichwaldiana) of the Prishchekent region, the lower part of the Maral Fm of the Kyzylkum Horizon, the lower part of the Gulioz Fm and the upper part of the Malandydarin Fm of the S-3 Gissar and Babatag Ridge. (160; 444).
GeoJSON
Fossils
Contains marine bivalve mollusks - Pycnodonta brongniarti Bron., P. queteleti Nyst., Ostrea plicata Sob., Aralocardia eichwaldiana Rom., Cultellus grignonensis Desh.; gastropods - Turritella uniangularis Lam., T. angulata Sow., T. supracarinata Alex., Vermetus bognoriensis Mantell.; radiolarians - Cenosphaera kuschnari Lipm., Ellipsoxiphus akkujensis Moks., Sethocyrtis bacaformis Bar., Theocampe altus Moks.
R.K. Makarova (282) distinguishes in these deposits: 1) layers with Aralocardia eichwaldiana; 2) layers with large Turritella (Turritella supracarinata).
Age
Depositional setting
Additional Information