Aginish Formation

Aginish Fm

Period:

Jurassic

Age Interval:

Early Callovian-Middle Oxfordian, U3

Province:
Ustyurt-Sultanuzdag

Type Locality and Naming

From the Aginysh borehole, Assakeaudan plateau, E. Ustyurt (zones of depression). Collective authors, 1971 (383, table 4, p.2). In 1965, V.N. Polyakov referred the Aginish Fm to the terrigenous p., and in 1967 to the Shakhpakhtin Fm.

Synonym: Aginyshskaya Formation, Агинишская св.

Lithology and Thickness

Consists of 4 packets.

First - clayey-sandy - gray compact clays, alternating with siltstone (aleurolites) and fine-grained sandstones. Thickness 33-100m.

Second - dark gray compact clays with thin carbonaceous detritus. Thickness 30-50m.

Third - clayey-sandy - interbedding of gray and greenish-gray aleurolitic sandstones with clays. Contains small shell detritus. Thickness 75-100m.

Fourth - clayey-calcareous packet - interbedded clayey siltstone (aleurolites), sandstones, limestones. Thickness 90-105m.

Lithology Pattern:

Sandy_claystone

Relationships and Distribution

Lower contact

Overlies the Kafaklin Fm transgressively

Upper contact

It is overlain by the Shakhpakhtin Fm.

Regional extent

Well E. Ustyurt. Type section of the Aginish plateau and Nikolaevskaya areas. The suite is included in the Kugitang Horizon (252) and belongs to the II and III Urtchinsky mining horizon.

GeoJSON

null

Fossils

Contains pollen Classopoliis up to 55-98% and others. In well 1 of the Otyunchi plateau, interval 1553-1565m, V.V. Kurbatov identified foraminifers Karaisella uzbekistanica Kurb., Lenticulina (Planularia) dubiaformis Kurb., Pseudocyclammina sp. and others

Age

foraminifers do not contradict the lower and middle Oxfordian (383, table 4, p.2). Dated to the end of the early Callovian and middle Oxfordian.

Age Span:

Beginning stage:

Callovian

Fraction up in beginning stage:

0.7

Beginning date (Ma):

162.66

Ending stage:

Oxfordian

Fraction up in the ending stage:

0.65

Ending date (Ma):

157.14

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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