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Amudarya Formation

Amudarya Fm


Period: 
Quaternary

Age Interval: 
Holocene, U6


Province: 
Ustyurt-Sultanuzdag

Type Locality and Naming

Along the river Amu Darya. [Flood plains South of Sultanuizdag => put with Pitynak; although along entire river in Uzbekistan.] N.P. Kostenko, 1953 (245, pp.183-205).

Synonym: Amudarya Complex, Амударьинский компл.


Lithology and Thickness

Sands, loams, and cover loams. Thickness up to 10 m. Riverbed, floodplain, and I floodplain terrace deposits are composed of sands, siltstone (aleurolites), and on the terrace by cover loams. Thickness up to 25m. Embedded in the deposits of the II floodplain terrace or overlies the riverbed sands of the upper Neopleistocene-Holocene and older.

The Aral Sea delta occupies the northern part of the southern Aral region. Formed by the Amu Darya River in the second half of the Holocene. Alluvial-lacustrine deposits (loams, loams, Thickness up to 10 m); deposits of the above-water delta in the lower reaches of the Amudarya (riverbed, floodplain deposits of the above-water delta, on elevated parts of the delta - interbedding of sands, loams, loams of riverbeds, near-riverbed ridges and flood-deposited (floodplain) overflows, Thickness 5-10m) and lake-bog deposits of the above-water delta in inter-channel depressions - reed peat of former swamps, Thickness up to 1 m; loamy sands, loams, thickness up to 3m.

In Southern Uzbekistan, the complex is represented by deposits of the channel, floodplain, I and II above-floodplain terraces (sandy-gravel and sandy-loamy deposits, thickness up to 3 m); alluvial-proluvial (sandy-gravel and boulder deposits), eolian sands, moraine and fluvioglacial deposits of the modern phase of glaciation.


Lithology Pattern: 
Sandstone


Relationships and Distribution

Lower contact

Overlies alluvial-lacustrine deposits of the upper modern links of undifferentiated and older rocks. Delta deposits lie on lake-alluvial upper modern links of unbroken, the boundary with which is drawn conditionally, and lake-bog - on alluvial deposits of the above-water delta.

Upper contact

Schematic stratigraphic column indicates this is the youngest unit

Regional extent

Valley of the Amu Darya River and surface of the Aral Sea delta. In the southern Aral region, it is represented by riverbed, floodplain, I and II floodplain terraces. The II floodplain terrace is distinguished to the south of Sultanuizdag. Used in the stratigraphic scheme of Quaternary deposits (A.I. Kim et al., 2000). It is correlated with the Akchadarya Gr and Aral Gr of the Pre-Aral.


GeoJSON

null

Fossils

Contains remains of mammals Equus caballus L., Ovis cf. aries, Bovidae, Gazella quturosa Omel., femur of Homo sapiens, monuments of the historical era of the 5th-4th centuries BC.

Alluvial-lacustrine deposits with Corbicula fluminalis (Müll.), Dressena polymorpha Pall.


Age 

Quaternary (Holocene)

Age Span: 

    Beginning stage: 
Holocene

    Fraction up in beginning stage: 
0.0

    Beginning date (Ma): 
0.01

    Ending stage: 
Holocene

    Fraction up in the ending stage: 
1.0

    Ending date (Ma):  
0.00

Depositional setting


Depositional pattern:  


Additional Information


Compiler:  

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