Cenozoic

Cretaceous

Jurassic

Triassic

Permian

Carboniferous

Devonian

Silurian

Ordovician

Cambrian

Neoproterozoic

Main source = Baratov, R.B., et al. (1976). Subdivisions of stratified and intrusive rocks of Tajikistan. Publishing House "Donish", Dushanbe, 269 pp. plus tables. Provided by Dr. Jovid Aminov, Nazarbayev University, Astana, Kazakhstan Translated to English by the GeoGPT group, Zhejiang Lab, Hangzhou, China--see About

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Zorabat Formation

Zorabat Fm

Period:

Cambrian

Age Interval:

(Є? zr), V1

Province:
SE Tajik (Central W Pamir)

Type Locality and Naming

delineated by V.I. Dronov and others (1960).

Synonym: Zorabatskaya suite, 3орабатская свита

Reference section:

Lithology and Thickness

In the eastern part of this region, in the Muzkol range, the suite has a thickness of 150 m and is composed of light, yellowish, lilac limestones with low-power (10-15 cm) interbeds of clay slates, colored in greenish and violet hues.

In the western part of the Central Pamir, in the Vanch Range, the thickness of the Zorabat Fm increases to 700 m. The Zorabat Fm consists of two packages. The lower package is dark gray dolomites and dolomitic limestones (350), the upper one is light gray dolomites with interbeds of limestones (350 m).

In the siliceous shales of the valleys of the Eastern Pshart and Ak-Baytal rivers (southern), there are gray, yellowish, and purple limestones, containing a package of colorful quartzites and gravels, V. I. Dronov (1963a),

Lithology Pattern:

Dolomitic limestone

Relationships and Distribution

Lower contact

The base of the suite is not exposed in Muzkol range. In Vanch range, according to the observations of S.V. Ruzhentsev (1970), it lies conformably with a gradual transition (and according to the observations of B. R. Pashkov (1962) and N. K. Sherbakov, unconformably) on the sandstones and quartzites of the Djamak Fm of the Riphean Vanch-Yazgulem Gr.

Upper contact

It is overlain conformably by the Ordovician Kozyndyn Fm.

Regional extent

It is widespread in the Central Pamir, western part of the Central Pamir, in the Vanch Range, and eastern part of this region, Muzkol range.

GeoJSON

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Fossils

The limestones contain remains of trilobites Palaeolenus pamiricus N. Tcherp., Sajanaspis (?) lauta N. Tchern., characterizing the lower half of the Lensk horizon. So far, on the Pamir, this is the only occurrence of Cambrian fauna.

Age

The Cambrian age of the Zorabat Fm is provisionally determined by its underlying position relative to the Kozyndyn Fm, which contains organic remains of the Tremadocian-Hirnantian (Pashkov, 1964a) at its base. However, V. I. Dronov and others (1960) and S. S. Karapetov (193) attributed the rocks with these remains to the Zorabat Fm, and its age is determined as Early and partly Middle Ordovician.

Age Span:

Beginning stage:

Fortunian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

538.80

Ending stage:

Cambrian Stage 10

Fraction up in the ending stage:

1.0

Ending date (Ma):

486.85

Depositional setting

Depositional pattern:

Additional Information

Compiler:

Extracted from Baratov, R. B. (1976). Subdivisions of stratified and intrusive rocks of Tajikistan. Donish, Lakhsh district, 276.