Neogene

Paleogene

Cretaceous

Jurassic

Triassic

Permian

Carboniferous

Devonian

Silurian

Ordovician

Cambrian

Neoproterozoic

Mesoproterozoic

Paleoproterozoic

Main source = Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian) Translated to English by the GeoGPT group, Zhejiang Lab, Hangzhou, China--see About

Gurud Formation

Gurud Fm

Period:

Jurassic

Age Interval:

Aalenian - early Bajocian, B1-B3

Province:
Bukhara-SW Gissar

Type Locality and Naming

In the village of Gurud, Surkhan Mountains, South-Western Gissar. I.E. Gubin, 1937 (164, p.123). Stratotype in the reference section of Kugitanga (Khodzharyz).

Synonym: Gurud Formation, Гурудская св.

Lithology and Thickness

Subdivided in complete sections into three subhorizons.

Lower subhorizon represented by channel sandstones, gravelites. Thickness up to 70m.

Middle subhorizon - clayey-sandy t. siltstone (aleurolites), sandstones, argillites, coals. Thickness 130-220m.

Upper subhorizon formed by sandy-clayey t. - sandstones, siltstone (aleurolites), argillites and coal seams. Thickness up to 70m.

Total thickness of the horizon up to 300 m.

Lithology Pattern:

Clayey sandstone

Relationships and Distribution

Lower contact

Transgressively overlies the Sandzhar Fm, Kimerex Fm, or Paleozoic

Upper contact

It is similarly overlain by the Degibadam Fm

Regional extent

South-Western Gissar, Mechetli, southern slope of the Gissar Range. Boreholes of the Bukhara-Karshi region and Turkmenistan.

GeoJSON

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Fossils

Contains large plant remains Clathropteris obolata Oishi, Coniopteris hymenophylloides (Brongn.) Sew. and others; freshwater bivalve mollusks - Kija tjazhinensis Leb., K. minima Rep. and others; conchostracans - Pseudostheria (Sphaeropsis) sixteliana Novoj., P. (S.) kampyrtepaensis Novoj., Cyricus resimus Novoj. and others; insects - Heteroptera, Paraplecoptera.

Age

Organic remains do not contradict the Aalenian - Bajocian. At the Tashkent stratigraphic conference (382, table 13) the horizon was dated to the early Jurassic - Bajocian and subdivided into Shargun Fm, Vandob Fm, Sherjan Fm (corresponding to the modern concept of the Gurud Horizon), Machaylin, Kampiltepin (corresponding to the modern concept of the Deghibadam Horizon) and Shelkan (now Tanygiduv horizon) (339; 383, table 4, p.3). V.V.Kurbatov, V.I.Troitsky (165) date the horizon to the Aalenian - early Bajocian.

Age Span:

Beginning stage:

Aalenian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

174.70

Ending stage:

Bajocian

Fraction up in the ending stage:

0.5

Ending date (Ma):

169.54

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)”