Bashguzhumdin Fm

Along the Bashguzhumdy River, Kuldyktau Mountains, Central Kyzylkum. Yu.A. Likhachev et al., 1963 (266, p.34).

Synonym: Bashguzhumdin Suite, Башгужумдинская св.

Under the name "bashguzumdy suite" by Yu.A. Likhachev et al. (266), a Lower Ludlow suite Thickness 1000m was distinguished. Ya.B. Aysanov and A.I. Egorov established that in this suite, A.A. mistakenly included differently aged limestones: Lower Devonian in Turkmentau, Beltau, and Tuzkoye, Wenlock in the area of the Uchkuduk, Darvaza, and Tuzkoye, Upper Ordovician and Llandovery in the Kazakasu, Kynyrtau, and Beltau mountains. Therefore, for the Bashguzhumdin Fm, limestones of Late Silurian age Thickness 600-700m, developed between the Oydyngbulak and Yamandjar syams, north of the Beshguzumdy kol, east and north of the Tozbulak granitoid massif (44), were retained.

The section of the suite in the Oydyngbulak-Yamandjar strip, north and east of the Tozbulak massif, and in Beltau is represented by marbled massive gray and dark-gray limestones with subordinate layers of banded, indistinctly layered fine-grained varieties. Thickness 600-700m.

In the area of the Tuzkoye elevation and the Darvaza mountains, four members (from bottom to top) are distinguished: the first (200m) - dark-gray organogenic, thin-bedded, bituminous limestones with layers of brownish-gray nodular siliceous-carbonate formations; the second (150m) - predominantly gray and light-gray, thick-bedded fine-grained dolomites with rare layers of black organogenic limestones; the third (130m) - gray, massive, nodular, organogenic limestones; the fourth (120m) - rhythmically interbedded massive, smoky and black limestones.

Remains of tabulates Favosites sp., Parastriatopora sp., P. (cf. tebenjkovi Tchern.); stromatoporoids Actinostroma">Actinostroma ex gr. malevskii Yavor.; pyro3 - Triplasma asiatica (Nikol.); crinoids Pentagonocyclicus cf. rimosus Schew., P. ex gr. scabrum Schew., P. ex gr. astericus Schew., Cyclocyclicus rarus Schew. determine the Late Silurian, Ludlow-Pridoli age of the suite.