Sandalash Fm

After the Sandalashskiy Ridge. A.F. Stepanenko in 1955-1956 distinguished it from the Karakasmakskaya suite. V.A. Nikolaeva, 1958 (437, pp.59-66). The holotype is in the Sandalash Range, in the valley of the Karakasmak River. In 1959, I.D. Doronkin separated the upper third of the S. suite into the independent Beshkent suite (475). V.V. Mikhailov and others (460) understand the S. suite in the volume of the lower part of the eponymous suite.

Synonym: Sandalashskaya Suite, Сандалашская св.

Siliceous-clayey, siliceous, carbonaceous-clayey, and carbonate-clayey slates, limestones, interlayers and lenses of sandstones, siltstone (aleurolites), dolomites, clayey limestones, gravellites. In siliceous slates, phosphorite concretions. At the base of the suite in the Sandalash Range - a horizon (5m) of dolomites, in the Pskem Range - conglomerates. Along A.F. Stepanenko, L.I. Turbina, I.D. Doronkin, V.V. Mikhailov, the suite includes small bodies of diabases, mandelsteins, andesidacites, subvolcanic bodies of dolerites. Laterally, the section is facially variable. Thickness 500-600m.

In the lower part of the suite, hyoliths, hyolithelminths, protocodonts, gastropods Pelagiella larenzi Kob.; rostroconch mollusks Heraultipegma sp.; sponges Chancelloria; brachiopods Kutorgina cf. cingulata (Bill.) of the lower Leningradian superhorizon; trilobites of the Amgin horizon - Triplagnostus gibbus (Linn.), T, stenorhaenis (Grunw.), Hypagnostus parvifrons (Linn.), H. truncatus (Brug.), Kooteniella superconvexus Ergal. and others. In the upper part, Late Cambrian trilobites Proceratopyge olenekensis Pork., Pseudagnostus impressus Lerm., Agnostus hedini Troeds., Pseudagnostus obsoletus Lerm., Charchaqia norini Troeds. and others (Sandalash Range). At the top of the suite - Arenig graptolites - Didymograptus cf. hirundo Salter., D. balhaensis Keller., D.riadus Lapw., Phyllograptus angustifolius Hall. and others, and Llanvirn - Expansograptus suecicus (Tullberg.), Isograptus cf. caduceus (Salter.), Glyptograptus dentatus pusillus Hsü. In the basin of the Karakorum River, Middle Cambrian-Middle Ordovician conodonts - Eoconodontus notchpeakensis (Müller.), Furnichina furnishi (Müller.), Prosagittodontus dahlmani Müller., Prooneotodus gallatini (Müller.), P. tenuis (Müller.), Westergaardodina tricuspidata Müller., Paracordylodus gracilis Lind., Paroistodus parallelus (Pand.) and others.