Upper Devonian carbonate reef complexes have been studied on the territory of the Kolyvan-Tom' Folded Area in sections in the right bank of Tom' River. Facies analysis of the exposed part of the reef complex indicates the predominance of fore-reef and continental margin depositional environments of a tectonically active margin. The identified conodont associations are represented by cosmopolitan representatives of the genera Ancyrodella, Ancyrolepis, Icriodus, Mehlina, Palmatolepis, Polygnathus and "Polylophodonta" suggesting a correlation with the punctata-jamieae, rhenana-linguiformis, triangularis and Lower crepida conodont zones. The largest conodont diversity occurs at the triangularis/crepida boundary. Biofacies analysis of ostracod distribution has led to identification of characteristic associations and their restriction to certain parts of the palaeobasin. Substage boundaries yielded ostracods with both smooth and ornamented shells. In the lower part of the substages, smooth forms predominate, whereas the middle and upper parts of the substages are characterised by forms with tuberculate and reticulated surface. Hollinella valentinae Beds were traced in the Upper Frasnian Solomino Formation, and Acratia granuliformis Beds were traced in the Lower Famennian Kosoy Utyos and lower Mitikha members. Isotope geochemistry of the Upper Devonian sections of the south of Western Siberia reveals Frasnian global events - the Middlesex/punctata and the Upper Kellwasser, their stratigraphic position confirmed by palaeontological data, as well as by the globally expressed negative carbon isotope anomaly. These boundaries are marked by changes in depositional regime reflecting sea-level eustatic fluctuations, which are complemented with faunal changes.

—Dataset on the Middle Devonian volcanic-carbonate–terrigenous sediments of Salair and the Kuznetsk trough, submerged northward under the Mesozoic–Cenozoic West Siberian geosyneclise (WSG) cover, have been presented. Mainly deep water sediments composed of thin- and fine-grained clastic material (with predominance of tephroids) and thin-, fine-clastic biodetrital limestones with slope slide breccia, as well as turbidites and peculiar “conglomerate-like” limestones (paleoseismites) were found. Sedimentary and geodynamic environments have been reconstructed for the Middle Devonian strata. Predominantly andesitic composition of pyroclastic ashes with fewer values of felsic and basic volcanic components have been determined. The structures related to the continental margin environments of the Siberian continent, the continental slope and its basement have been found. According to sedimentary and geochemical data, the paleogeodynamic environment within the studied region was relatively stable and generally corresponded to the island arc conditions. The paleoclimate of the source area changed from semi-humid in the late Emsian–early Eifelian (Malaya Salairka age) to aridic in the middle Givetian (Kerlegesh age). Basin sediments formed in the deep water oxic environments with good water aeration, excepting euxinic environments found in the lowermost part of studied succession.

Дана литологическая характеристика среднедевонского вулканогенно-карбонатно-терригенного комплекса отложений Салаира и Кузнецкого прогиба, погружающегося на севере под мезозойско-кайнозойский чехол Западно-Сибирской геосинеклизы. Преобладают отложения глубокого бассейна, представленные тонко-, мелкозернистыми обломочными разновидностями (с доминированием вулканического материала) и тонко-, мелкообломочными биодетритовыми известняками со слоями оползневых брекчий, а также турбидитами и своеобразными «конгломератовидными известняками» (палеосейсмитами). Реконструированы седиментационные и геодинамические обстановки формирования среднедевонского комплекса. Установлен преобладающий андезитовый состав пирокластики и меньшее значение в осадках кислых и основных вулканических компонентов. В этом регионе определены признаки окраинно-континентальных обстановок Сибирского континента, склона и его основания. Палеогеодинамическая обстановка, согласно седиментационным и геохимическим данным, оставалась в целом одной и той же и соответствовала, по геохимическим данным, условиям островных дуг. Палеоклимат питающей провинции изменялся от семигумидного в позднем эмсе-раннем эйфеле (малосалаиркинское время) к аридному в среднем живете (керлегешское время). Отложения в глубоководном бассейне формировались в окислительной обстановке с хорошей аэрацией вод, исключая эвксинские обстановки в самой нижней части изученного разреза. Dataset on the Middle Devonian volcanic-carbonate-terrigenous sediments of Salair and the Kuznetsk trough, submerged northward under the Mesozoic-Cenozoic West Siberian geosyneclise (WSG) cover, have been presented. Mainly deep water sediments composed of thin- and fine-grained clastic material (with predominance of tephroids) and thin-, fine-clastic biodetrital limestones with slope slide breccia, as well as turbidites and peculiar “conglomerate-like” limestones (paleoseismites) were found. Sedimentary and geodynamic environments have been reconstructed for the Middle Devonian strata. Predominantly andesitic composition of pyroclastic ashes with fewer values of felsic and basic volcanic components have been determined. The structures related to the continental margin environments of the Siberian continent, the continental slope and its basement have been found. According to sedimentary and geochemical data, the paleogeodynamic environment within the studied region was relatively stable and generally corresponded to the island arc conditions. The paleoclimate of the source area changed from semi-humid in the late Emsian-early Eifelian (Malaya Salairka age) to aridic in the middle Givetian (Kerlegesh age). Basin sediments formed in the deep water oxic environments with good water aeration, excepting euxinic environments found in the lowermost part of studied succession.

The first detailed isotope-geochemical study of carbonate deposits has been performed in the Lower Famennian stratotype section of the northwestern Kuznetsk Basin (Kosoy Utyos), which was localized in the middle latitudes of the Northern Hemisphere in the Late Devonian. The δ13Ccarb, δ13Corg, and δ18O variation curves were constructed for the section deposits. Geochemical and petrographic studies of carbonates allowed allocation of samples that underwent postsedimentation alteration and exclude them from further interpretation. Compared with coeval sections in the other world's regions, the Kosoy Utyos section is characterized by higher δ13Ccarb values, up to 5.4‰, whereas the maximum value in subequatorial area sections is 4‰. The isotope shift amplitude of the studied section reaches 4.6‰, which is 1.5‰ higher than those in other regions. The δ18O values are 3‰ lower than the ones of the world's coeval sections. The results obtained show that δ13C and δ18O variation trends differ from those of coeval subequatorial sections. The high shift amplitude and maximum δ13Ccarb values in the Kosoy Utyos section are due to the shallow-water carbonate sedimentation environments on the Siberian continental shelf and, probably, the lower temperatures of waters in the middle latitudes as compared with the subequatorial areas.

The fi rst detailed isotope-geochemical study of carbonate deposits has been performed in the Lower Famennian stratotype section of the northwestern Kuznetsk Basin (Kosoi Utyos), which was localized in the middle latitudes of the Northern Hemisphere in the Late Devonian. The δ13C carb , δ13C org , and δ18О variation curves were constructed for the section deposits. Geochemical and petrographic studies of carbonates allowed allocation of samples that underwent postsedimentation alteration and their exclusion of from further interpreta- tion. Compared with coeval sections in the other world's regions, the Kosoi Utyos section has higher δ13C carb values, up to 5.4 ‰, whereas the maximum value in subequatorial area sections is 4 ‰ The isotope shift ampli- tude of the studied section reaches 4.6 ‰, which is 1.5 ‰ higher than those in other regions. The δ 18 О values are 3 ‰ lower than the ones of the world's coeval sections. The results obtained show that the δ13C and δ18О variation trends differ from those of coeval subequatorial sections. The high shift amplitude and maximum δ 13 Ccarb values in the Kosoi Utyos section are due to shallow-water carbonate sedimentation environments on the Siberian continental shelf and, probably, the lower temperatures of waters in the middle latitudes as com- pared with the subequatorial areas. Isotopes, carbon, oxygen, carbonates, Famennian Stage, Upper Devonian, northwestern Kuznetsk Basin