Home Multi-Country Search About Admin Login

Search by
Select Region(s) to search
Hold Ctrl (Windows/Linux) or Command (Mac) to select multiple
Isfarin Formation

Isfarin Fm


Period: 
Silurian

Age Interval: 
Upper Silurian (Gorstian-Pridoli), F11


Province: 
Fergana

Type Locality and Naming

Along the Isfara River, Turkestan-Alay Mountain region, S. Fergana. O.I. Nikiforova, 1937 (329, pp. 5-62). Stratotype on the Isfara River, south of the Matchay (October) settlement. Initially distinguished at the level of layers. In 1958 (467), A.E. Dovzhikov et al. distinguished the Matchay Fm, which included the Isfarin Fm.

Synonym: Isfarinskaya Suite, Исфаринская св.


Lithology and Thickness

Thin-bedded and platy clayey limestones with horizons of thick-bedded and massive organogenic varieties and interlayers of silty (aleurolites) and clayey slates of greenish-gray, gray, and brown colors. Thickness 560-600m.


Lithology Pattern: 
Clayey limestone


Relationships and Distribution

Lower contact

Conformably overlies the pentamerous limestones of the Dalian Mountains

Upper contact

Conformably overlain by the limestones of the Kunjak Mountains

Regional extent

Southern Fergana.


GeoJSON

null

Fossils

Contains stromatoporoids - Intexodictyon bavaliense posochovae Less., Favosites effusus Klaam., F. ferganensis Orlov, F. weberi Orlov, Squameofavosites ettkichuensis Chekh., Emmonsiella saaminica (Chekh.), Heliolites ex gr. interstinctus Linne, Atrypella prunum Dolm., Eoreticularia tschernyschevi mattchensis Nikif., Nikiforovaene linxoides Nikif., Tadschikia wilsoniaformis Nikif., Encrinurus ex gr. punctatus Wahl., Colonograptus sp., Pristiograptus sp., Monograptus transgrediens, etc.


Age 

Upper Silurian (Gorstian-Pridoli)

Age Span: 

    Beginning stage: 
Gorstian

    Fraction up in beginning stage: 
0.0

    Beginning date (Ma): 
426.74

    Ending stage: 
Pridoli

    Fraction up in the ending stage: 
1.0

    Ending date (Ma):  
419.00

Depositional setting


Depositional pattern:  


Additional Information


Compiler:  

A.I. Kim – In: GeoGPT translation of: ”Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian)"