Shakhriomon Gr

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

Shakhriomon Gr

Period:

Ordovician

Age Interval:

Middle-Upper Ordovician, Z1, Z1a

Province:
Zarafshan-N.Gissar

Type Locality and Naming

Named after the Shakhrimon ridge, Zarafshan Range. A.I. Kim, 1963 (224, p.73).

Synonym: Shakhriomon Series, Шахриомонская св.

Lithology and Thickness

Lower part of the section consists of yellowish-green, green polymictic and quartz siltstone (aleurolites), sandstones, calcareous-clayey slates, gravelites, conglomerates with layers of tuffaceous sandstones and tuffs of quartz porphyries. Thickness 200-250m.

Upper part of the section - quartz-feldspar sandstones and siltstone (aleurolites), organogenic aleurolitic limestones and dolomites with layers of calcareous siltstone (aleurolites) (Thickness 76m). Thickness of the series 276-326m.

Lithology Pattern:

Coarse-grained sandstone

Relationships and Distribution

Lower contact

The lower contact is unknown.

Upper contact

Overlain conformably by the South Sumsar Fm.

Regional extent

Zeravshan-Gissar mountain region, basin of the Kashkadarya River, Shakhrimon ridge, Sumsar.

GeoJSON

null

Fossils

Contains a diverse fauna of the Middle Ordovician: brachiopods - Onniella chancharica Sev., Strophonema lebediensis septata Rozm., Dolerorthis intermadius Nikif. and others; trilobites - Placoparina sedgwicki (Mc'Coy), Calymenesum tingi (Sun.) and others; echinoderms - Echinosphaerites aurantium Gyll., Bystrowicrinus quinguelobatus Yelt., Ristnacrinus marinus Opik. and others; tabulates - Lyopora sp.

Upper part – with fauna of the Late Ordovician: graptolites - Paraorthograptus (Pacificograptus) pacificus Rued,; tabulates - Lyopora regularis Kim, Catenipora tapaensis Sok. and others; rugose - Bodophyllum osmundense Naum., Sumsarophyllum patelaris Lavr. and others, brachiopods - Dolerorthis intermedius Nikif., Sowerbyella intricata Nikif. and others.

Age

Dated as Middle-Late Ordovician based on organic remains. (226; 441; 460).

Age Span:

Beginning stage:

Darriwilian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

469.42

Ending stage:

Rhuddanian

Fraction up in the ending stage:

0.2

Ending date (Ma):

442.56

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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