Tekhar Fm
Type Locality and Naming
It was delineated by N. G. Mash'taler in 1962 on the right slope of the Vanch River valley.
Synonym: Tekharskaya Suite, Техарвская свита
Reference section:
Lithology and Thickness
The suite consists mainly of greenstone, fissured or massive rocks. Among them, acidic plagioclase, amphiboles, epidote, chlorite, carbonates, sphene, ilmenite, pyrite, limonite have been found. The relics of the original rocks are difficult to establish, but they clearly indicate that the described formations belong to the products of greenstone metamorphism of volcanics, mainly of basic composition. Rarely, relics of acidic effusives are noted. There are layers of quartzitic sandstones, phyllitic slates, and small lenses of light reef limestones, the amount of which increases in the basins of the Fedchenko glacier and the Bal'landkiiyk River. The thickness of the suite is difficult to determine, but it is likely close to 2000 m.
Relationships and Distribution
Lower contact
The Tekhar Fm lies without apparent unconformities on the green slates of the Upper Silurian – Devonian of the Skoy? Shirogovat Fm.
Upper contact
Overlying formations are unknown.
Regional extent
It is distributed in the central and western parts of the Karakulsky District. N. G. Mash'taler, A. Kh. Kafarskii and I. V. Pyzyanov, who conducted geological mapping in the western part of the Northern Pamir, correlate the volcanic rocks of the Tekhar Fm with the Tournaisian and Visean greenstone rocks of the Fortambek Fm and Devlokhan Fm
GeoJSON
Fossils
In the lenses of limestones in the considered suite on Fedchenko glacier (near the weather station) and in the basin of the Bal'yandkiik River, E. S. Chern'er discovered Permian, more precisely undeterminable, Schubertella sp., Triticites sp., Pseudofusulina sp., Parafusulina sp.
Age
Depositional setting
Additional Information
Questions about the primary composition of the rocks of the Tekhar Fm (техарвской свиты), its age, as well as about the correlation of its typical sections located in the Vanch River valley with the rocks exposed along the Fedchenko glacier and the Bal'yandkiik River, require further research. For the understanding of the geology of the south of the Northern Pamir, these are among the most important problems.