Aristantau-Central Formation

Aristantau-Central Fm

Period:

Devonian

Age Interval:

Upper Devonian (Frasnian), K8

Province:
Kyzylkum Region

Type Locality and Naming

Along the mountains of Aristan-Tau, Central Kyzylkum. A. K. Bukharin et al., 1982f.

Synonym: Central Aristantau Suite, Центральноаристантауская св.

Lithology and Thickness

Divided into two sub-suites.

Upper (thickness 66-112m) - dolomites, limestones with lenses and constrictions of siliceous rocks, in the roof lens-like layers of calcareous conglomerates.

Lower (thickness 247m) - black, thin- and medium-bedded and dark gray organogenic nodular limestones with layers of gray and light gray dolomites.

Lithology Pattern:

Dolomitic limestone

Relationships and Distribution

Lower contact

With erosion, locally conformably, overlies the limestones of the Beshashik Fm

Upper contact

Conformably overlain by the Janahmetskaya Fm (Dzhanakhmet Fm).

Regional extent

Central Kyzylkum, southwestern part of the Aristan-Tau mountains. It is an analogue of the lower part of the Belikuduk Fm (495).

GeoJSON

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Fossils

Upper – Contains stromatoporoids - Atellodictyon cf stelliferum Stearn., Stromatopora undata Riab., Stachyodes ex gr. costulata Less., Novitella tschussovensis (Yavor.); brachiopods - Emanuella subumbona Hall., Theodossia anossofi Vern., T. katavensis Khod., T. livensis Nal.

Lower – Contains stromatoporoids - Stachyodes ex gr, costulata Less., Actinostroma">Actinostroma densatum Lec., Trupetostroma">Trupetostroma ex gr. pingue Lec., Parallelopora volansis Riab.; brachiopods - Wyella ex gr. suburalica Khod., Gypidula globa Bronn., Theodossia evlanensis Nal.

Age

Upper – characteristic of the late Frasnian and Famennian age (165; 495). Lower – of early Frasnian age

Age Span:

Beginning stage:

Frasnian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

378.90

Ending stage:

Frasnian

Fraction up in the ending stage:

1.0

Ending date (Ma):

371.10

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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