Surkhantau 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

Surkhantau Gr

Period:

Proterozoic, Cambrian

Age Interval:

Ediacaran- Cambrian Stage 4, B1

Province:
Bukhara-SW Gissar

Type Locality and Naming

Along the Surkhantau Ridge, South-Western Gissar. V.A. Khokhlov, 1970 (307, p.73)

Synonym: Surkhantau Series, Сурхантауская сер.

Lithology and Thickness

The series includes the Malyangur Fm, Malyand Fm, and Khandizin Fm. Amphibole, cordierite-biotite, and biotite-sillimanite gneisses, crystalline biotite schists with intersecting and layered bodies of cordierite granites, quartzite layers and amphibolites, biotite plagio-gneisses, and granito-gneisses. Thickness 4300m.

According to I.M. Mirkhodzhaev et al. (307), the rocks of the series underwent greenschist diaphthoresis (silicification, chloritization, muscovitization). The section is predominantly composed of primary sedimentary (pelitic) rocks, among which, in the upper part, there are acid and intermediate effusive rocks.

Lithology Pattern:

Gneiss

Relationships and Distribution

Lower contact

Upper contact

Regional extent

Exposed in the Surkhantau Ridge in two separate outcrops.

GeoJSON

null

Fossils

Age

The age of the series is interpreted differently. V.A. Khokhlov (432), I.M. Mirkhodzhaev et al. (307), M.A. Akhmedjanov et al. (73; 75), R.N. Abdullaev (165), V.V. Mikhailov (460) based on the high degree of regional metamorphism, radiological dating of the time of formation of amphiboles from the Khandizin Fm - 525 million years (Early-Middle Cambrian), correlation with reliably dated Precambrian metamorphic complexes of the Garm block, etc., consider the age of the rocks of the series to be Precambrian (conditionally Lower Proterozoic, Lower-Middle Proterozoic, or Proterozoic)E.D. Bezuglov et al. (92), A.V. Pokrovsky (349), A.K. Bukharin et al. (122) based on the discovery of Paleozoic microfossils in the Khandizin Fm, which is part of the series, assign it to the Lower Paleozoic, Lower-Middle Cambrian, Lower Cambrian-Lower Silurian. On the State Geological Map-500 of Uzbekistan (460), it is conditionally assigned to the undivided Upper Proterozoic.

Age Span:

Beginning stage:

Ediacaran

Fraction up in beginning stage:

0.0

Beginning date (Ma):

635.00

Ending stage:

Cambrian Stage 4

Fraction up in the ending stage:

1.0

Ending date (Ma):

509.00

Depositional setting

Depositional pattern:

Additional Information

Compiler:

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