Urakh Fm
Period:
Proterozoic
Age Interval:
Tonian, B1
Province:
Bukhara-SW Gissar
Type Locality and Naming
Along the Say Ura, Gissar Range. O.N. Nikitina et al. in 1993 (460, p. 36-37). Stratotype in the Say Ura valley.
Synonym: Urakh Suite, Урахская св.
Lithology and Thickness
Biotite slates, amphibole-biotite slates, biotite-amphibole slates, plagiogneisses, amphibolites, quartzites with lenses of marbles. At the base - (thickness 12m) metaconglomerate-breccia. Thickness 500m.
Lithology Pattern:
Sandy_claystone
Relationships and Distribution
Lower contact
Lies with angular unconformity on the Mizat Fm
Upper contact
It is unconformably overlain by Carboniferous deposits.
Regional extent
Southwestern Gissar, Say Ura valley.
GeoJSON
null
Fossils
Age
Age conditionally early Proterozoic is accepted based on lithopetrographic similarity of these deposits with formations of the Khodzhabuzbak Fm, Aylanar Fm and the development of migmatization and granitization typical for highly metamorphosed Proterozoic rocks of the SW Gissar (Nikitina et al., 1993). S.K. Ovchinnikov (335), D.A. Rubanov (385) conditionally attributed these formations to the Proterozoic, A.V. Pokrovsky (349), I.M. Mirkhodzhaev et al. (307), V.E. Golovin et al. (1981), A.K. Bukharin et al. (122) consider them Lower Paleozoic; on the State Geol Map-500 of Uzbekistan (460) they are conditionally attributed to the Proterozoic.
Age Span:
Beginning stage:
Tonian
Fraction up in beginning stage:
0.55
Beginning date (Ma):
846.00
Ending stage:
Tonian
Fraction up in the ending stage:
1.0
Ending date (Ma):
720.00
Depositional setting
Depositional pattern:
Additional Information
Compiler:
B.B. Muxaŭlov – In: GeoGPT translation of: “Abduazimova, Z.M. (Ed.), 2001. Stratigraphic Dictionary of Uzbekistan. IMR (Institute of Mineral Resources), Tashkent, 580 pp. (In Russian)”