Murynkuduk Formation

Murynkuduk Fm

Period:

Carboniferous

Age Interval:

Upper Bashkirian-Lower Moscovian, K5a

Province:
Kyzylkum Region

Type Locality and Naming

Along the Muryndyuk, South (?) Tamdytau, Central Kyzylkum. P.N. Podkopaev et al. in 1965 (386, p. 37), age and volume were clarified. Z.M. Abdazimova et al. (10, pp. 3-6).

Synonym: Murynkudukskaya Formation, Мурынкудукская св.

Lithology and Thickness

Upper part of the section (thickness 60m) consists of silty (aleurolitic) and argillitic slates, interbedded with siltstone (aleurolites), sandstones, less often layers (thickness 5-15m) of organogenic clastic limestones and calcareous sandstones. The predominant color of the rocks is reddish, pinkish-brown, less often green or greenish-gray.

Lower part of the section - coarse clastic p. (thickness 11-20m) - polymictic boulder-cobble conglomerates, composed of poorly rounded fragments of organogenic clastic limestones of gray and dark gray color.

The total thickness of the suite is 70-80, no more than 100m.

Lithology Pattern:

Claystone

Relationships and Distribution

Lower contact

It lies with erosion on the Shayandin Fm.

Upper contact

The upper contact is unknown. Schematic stratigraphic column indicates this is the uppermost unit in K5a

Regional extent

Central Kyzylkum, along the southern foothills of the Aktau, Shushchatau ranges and along the northern foothills of the Muruntau range.

GeoJSON

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Fossils

Upper part - Layers of limestones and calcareous sandstones contain Early Moscovian foraminifers - Eostaffella pseudoovoidea Reitl., E. ex gr. mutabilis Raus., Seminovella elegantula Raus., Schubertella ex gr obscura Lee et Chen, Pseudostaffella cf. korobezkikh Raus. et Saf., Neostaffella cf. proozawai Kir., Pseudoendothyra mathildae (Dutk.), Profusulinella staffellaeformis Kir., P. ex gr. prisca (Depr.), Verella sp., Endothyta sp. and others.

Lower part of the section - In the cement of the conglomerates, Late Bashkirian-Early Moscovian foraminifers were found - Ozawainella angulata (Col.), Endothyra sp., Pseudostaffella sp., Profusulinella cf. oblonga Pot., P. ex gr. staffellaeformis Kir., Aljutovella sp.

Age

It belongs to the Upper Bashkirian-Lower Moscovian sub-stages of the Middle Carboniferous (10). The age and span of the formation were interpreted differently. P.N. Podkopaev et al. (1965) attributed it to the Upper Paleozoic; Ya.B. Aysanov et al. (1986) - to the Lower sub-stage of the Moscovian stage of the Middle Carboniferous; Z.S. Rumyantseva (386) and in the Strat. vol. (439) limited the age to the Late Moscovian epoch, A.K. Bukharin et al. (1990) considered the age to be Late Devonian-Early Carboniferous. In these researchers, mainly due to the inclusion of deposits of another age, the thickness of the suite reached from 500 to 1000 m. A significant correction of the span of the formation was made as a result of special biostratigraphic studies in the early 90s (Abdazimova et al., 1992; 1993; 10).

Age Span:

Beginning stage:

Bashkirian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

319.28

Ending stage:

Moscovian

Fraction up in the ending stage:

0.5

Ending date (Ma):

311.09

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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