Beshashik Fm
Type Locality and Naming
Along the Beshashi section, Aristantau Mountains, Central Kyzylkum N.M. Larin, 1989 (495, pp. 42-43).
Synonym: Beshashchikskaya Suite, Бешашикская св.
Lithology and Thickness
Bedded, predominantly dark-gray organogenic limestones, interbedded with micritic clayey varieties with admixtures of red-brown calcareous siltstone (aleurolites) and rare dolomite layers, in the lower part - layers of brecciated dolomitized limestones. Thickness 254m.
Relationships and Distribution
Lower contact
Along the bedding, it lies on the rocks of the Ayakuduk Fm (495), with erosion
Upper contact
Sometimes conformably overlain by the Central Aristantau Fm (165).
Regional extent
Central Kyzylkum, Aristantau Mountains. Stratotype in the northern wing of the Centralaristantau anticline. N.V. Cherkashenko et al. (495) indicate the unconformable overlap of the Beshashik Fm by the Aristantau-Central Fm. [=> transition in facies, rather than contact?]. In Muruntau, the age equivalent of the Beshashik Fm is the upper part of the Auliekudzhumdin Fm.
GeoJSON
Fossils
Contains stromatoporoids - Actinostroma">Actinostroma devonense Lec., A. clathratum Nich., A. ex gr. septatum Lec. and others; corals - Scoliopora sp. (ex gr. denticulata M.E. et H.), Caliopora ex gr. reducta Yanet. and others, brachiopods - Stringocephalus burtini Deff., Chascothyris tschernyschevi Hall., Teodossia karatavensis Nal. and others of Givetian age.
Age
Depositional setting
Additional Information