Sargardon Formation

Sargardon Fm

Period:

Carboniferous

Age Interval:

Tournaisian, CK5, CK7

Province:
Chatkal-Kuramin Region

Type Locality and Naming

Along the Sargardon River, a tributary of the Akbulak River, basin of the Chatkal River, Chatkal Range. O.I. Sergun'kova, 1959 (382, p.55) in the rank of mountains; as a suite, 1965 (457, p.188).

Synonym: Sargardon Suite, Саргардонская св.

Lithology and Thickness

Divided into normally stratified thick-bedded limestones and coeval large organogenic structures of the "Kulossinsky" type. Normally stratified deposits are light gray, thick-bedded, sparitic, often crinoidal limestones. Thickness 100-140m. Organogenic structures are represented by large biostromes (Paltau), biostromal masses (Aksarsay), biostromal ridges (Kulossyo). Thickness 100-300m. Composed of light gray massive limestones. In the central parts of the masses, biostromal "stromatocoid" limestones predominate, and in the marginal parts, organogenic-detrital, detrital varieties. Organogenic structures of the " Kulosyn Fm " type usually have a flat lower surface.

Lithology Pattern:

Limestone

Relationships and Distribution

Lower contact

They lie conformably on cherty limestones of the Kulosyn Fm (Chatkal Ridge) or on medium-bedded limestones of the Taldybulak Fm (Pskem, Ugam ridges).

Upper contact

Everywhere they are conformably overlain by silicified limestones of the Irisuy Fm. The upper boundary is usually uneven, with local breaks and the absence of part of the Lower Visean deposits in some places. Laterally (to the south), they are replaced by thin-bedded silicified limestones of the Kuylyuk Fm, and in the direction to the north - by normally stratified thick-bedded limestones; in the Chatkal region, they are conformably overlain by the Irisuy Fm.

Regional extent

Chatkal, Koksuysky, Pskemsky, Ugamsky ridges. Stratotype (neostatotype) in the basin of the Akbulak River (Terekli River).

GeoJSON

null

Fossils

Conodonts - Dollymae bonckaerti Groes., Pseudopolygnathus pinnatus Vog., Gnathodus cuneiformis M. et T.; ammonoids - Merocanites djaprakensis (Libr.), Heliocyclus tianshanicus (Libr.), Ammonellipsites djapracensis (Libr.); brachiopods - Leptagonia analoga Phill., Pustula puxidiformis Kon., Pugnax acuminata Mart. (Tkachev et al., 1992, 1996).

Age

The Late Tournaisian age of the Sargardon Fm (including organogenic structures) is substantiated by conodonts. In the Strat. Sl. (439) and on the State Geol. Map-500 of Uzbekistan (460), the suite is assigned to the Lower Visean.

Age Span:

Beginning stage:

Tournaisian

Fraction up in beginning stage:

0.9

Beginning date (Ma):

347.99

Ending stage:

Visean

Fraction up in the ending stage:

0.1

Ending date (Ma):

345.09

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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