A paleogeographic scheme of the distribution of glaciers and ice-dammed lakes during the last global cooling (MIS-2) was compiled based on a detailed large-scale geomorphological survey. The levels and volumes of ice-dammed lakes during the first and second late Pleistocene glaciations, as well as a rockfall-dammed lake whose formation is not associated with glaciers of the MIS-2 era, were reconstructed.

The Gorny Altai is part of the system of intracontinental Cenozoic orogens that originated from the Eurasia-India collision. There is crustal contraction, which is followed by numerous earthquakes, and the highest concentration of earthquake sources is observed in the south-eastern part of the region. The system of paleoearthquake surface ruptures in the Kubadru Fault Zone was studied at three representative sites using the GPR method in conditions of weakly consolidated coarse clastic deposits in the upper part of the section and permafrost development. UAV aerial photography and trenching supported the geophysical studies. By using a 250 MHz antenna, we determined morphological parameters of paleoseismic scarps with high accuracy and learned about the fault's deep structures up to 8 m. A 100 MHz antenna provided the same information up to 10 m. Identifying active faults by looking for reflection discontinuities and chaotic reflections is not enough. Additional features from GPR datasets are necessary to detail the internal structure of the seismogenic fault zone. These are subvertical high-amplitude zones that can be traced to depths of up to 6-8 metres. The presence of such zones can be explained by the fracturing of rocks and sediments, their waterlogging, the development of processes of seismogenic fluidization of soils. Deposits of colluvial wedges are distinguished on GPR profiles as depressions filled with layered deposits, with a series of parallel inclined reflectors. A 3D GPR survey helped identify paleofaults over a larger area and eliminated errors on individual profiles. The permafrost table sharply limited the depth of sounding. A low frequency of the spectrum, a smooth decrease in amplitudes to minimum values characterized rocks and sediments in the frozen state. Shallow reflections on the GPR profiles correspond to the lithological complexes observed in the trenches. The acquired findings demonstrate the importance of employing geophysics in investigating the surface ruptures of paleoearthquakes both at the stage of determining the location and kinematics of seismogenic ruptures prior to trenching, and at the stage of substantiating the history of the formation of faults.

We present the first magnetotelluric sounding (MTS) data acquired in the southern part of the Lena River delta which is a junction zone of the Siberian Craton and the Verkhoyansk fold-and-thrust belt, in the transition zone from the Eurasian Continent to the shelf of the Laptev Sea. The MTS data were used to construct a vertical section of the bulk electrical resistivity (ER) structure of the Earth’s crust down to a depth of 8 km. The upper high-resistivity layer (320–1000 Ohm m) corresponds to the permafrost rocks ranging in thickness from 1 km to 400 m under the channels of the Lena River. The underlying deformed Mesoproterozoic–Lower Triassic rocks can vary in composition, but they are poorly differentiated in ER values (110–240 Ohm m). We detected three low-resistivity anomalies (10–60 Ohm m) related to the fluid-saturated core and damage zones of active faults. A deep-lying high-resistivity anomaly (320–350 Ohm m) identified at the northeastern part of the section can correspond to the Lower Proterozoic or Archean metamorphic rocks.

Shrinking of intermontane basins and expansion of their flanking ranges by reverse faulting and backthrusting in two counter-dipping systems is a typical mechanism of crustal shortening and mountain building in Central Asia. This mechanism is realized along the Kurai Fault Zone (southeastern Gorny Altai). Motions on two reverse fault systems maintained thrusting of the Kurai Range and the Kubadru Uplift on the Kurai Basin sediments and caused the growth of a foreberg before the mountain front. Forberg separates narrow Aktash Basin from the Kurai Basin. The paleoearthquakes were generated by reverse faults that delineate the foreberg. Analysis of the QuickBird satellite images, drone imagery, trenching, archaeoseismological research, radiocarbon dating, dendrochronology, and previous results show that eleven large (& Mcy;(W) = 6.5-7.6) paleoearthquakes left traces as surface ruptures along the Kurai Fault Zone: twice before 7.5 ka BP, three events between 7.5 and 5.9 ka BP (7.0, 6.3, and 5.9-5.8 ka BP), one from 5.8 to 4.6 ka BP, four more at 4.6, 3.2, 1.5, and 1.3-1.2 ka BP, and the ultimate earthquake no older than 1450-1650 AD. The time difference between large earthquakes was from 200 to 1700 years. Surface faulting occurred mainly along the northern border of the foreberg where fault scarps are progressively younger northward and the Cenozoic sediments of the Aktash Basin thus become involved into uplift. GPR data to a depth of 12 m confirm the complex structure and slip geometry of the observed surface ruptures. The fault scarps are located < 1 km from the planned route of the gas pipeline from Russia to China, and the potential seismic hazard has to be taken into account in its design and construction.

The kinematic characteristics of faults included in the structure of the active Katun Fault in Gorny Altai have been determined by methods of structural–paragenetic and cataclastic analysis of disjunctives (faults). It is proven that the Katun Fault is a strike-slip fault developing in different areas under transpressive or transtensional conditions. The most recent grabens along the Katun fault were formed under conditions of strike-slip displacements and locally manifested horizontal extension or extension with shear.

The Kurai Fault Zone (KFZ) is one of the most hazardous seismogenic structures in the Gorny Altai (Russia), which bounds the largest Kurai and Chuya intermontane basins from the north. Trenching studies, radiocarbon dating of colluvial wedge deposits, and 230Th-U dating of seismogenic travertine of the Meshtuyaryk field showed that the fault scarp in the northwestern part of the Chuya Depression was formed by earthquakes that occurred ca. 9.5, 7.7, 5.8, and 4.8–3.4 ka BP. The last two palaeoearthquakes are younger than 3.2 ka BP. The parameters of seismogenic ruptures, as well as the distances between coeval seismogenic travertines along the KFZ, yielded estimates of the Mw of the four oldest palaeoearthquakes as 6.8–7.6 and ESI 2007 shaking intensities of VIII–XI. The results of 230Th-U dating suggest that deposition of the Meshtuyaryk travertines was triggered by three strong palaeoearthquakes at ca. 9.5, 7.7, and 4.8–3.4 ka BP, which activated faults and caused a rapid rise along them of ambient-temperature bicarbonate groundwaters previously sealed in deep-seated limestone aquifers.

The areal stratotype of the Chibit glaciation is characterized in the stratigraphic scheme of the Quaternary deposits of the Altai-Sayan mountainous region, corresponding to the last glacial maximum, i.e. the fourth stage of the Upper Neopleistocene of the Russian stratigraphic chart. The reference geological sections of the diamictons of the Chibit horizon are described. A Paleogeographic map showing the area of the Chibitsky and Maasheysky glaciers during the LGM is presented. The map was compiled on the basis of remote sensing materials, field geomorphological observations and field geological data. The boundaries of the glacialdammed Baratal Lake are shown based on flooding level of 1700 m. This level corresponds to the upper terraces on the northeastern edge of the Kurai depression. The boulder-gravel deposites formed as a result of the Baratal lake breakthrough were identified in the old valley of the Chuya River. They compose the 57 m high terrace, that is cut into the Chibit moraine. It has been established that the Chibit moraine is embedded into the Saldzhar superflood sequence. Therefore, the Saldzhar and Baratal outbursts are of different ages and scales.

The article presents preliminary results of the study and characterization of the neotectonic processes manifestations in Denisova Cave, their influence on the formation and post-sedimentation changes of Pleistocene cave deposits. In Denisova Cave, traces of paleoearthquakes are examined in sections of sedimentary strata of the Main, East and South Chambers. The main types of earthquakeinduced deformations are described. A chronological assessment of the episodes of ancient seismic events recorded in the stratigraphic sequence of the cave is given. It was established that as a result of seismic deformations, the displacements of the layers turned out to be insignificant and their boundaries are well correlated. There was no mixing of the substance of different lithological units and, accordingly, the archaeological finds and paleontological material contained in them. We also assume that neotectonic activity could have infl uenced the living conditions of primitive man as one of the environmental factors.

The south-eastern Gorny Altai is one of the most hazardous seismogenic area in the north of Central Asia. We present a synthesis of field, 230Th-U geochronological, mineralogical and geochemical data collected on seven Quaternary travertines. All travertines occur within the zones of active faults that border the Chuya and Kurai intermontane basins. Travertine cement mainly comprises calcite (with minor amounts of aragonite), which cements alluvial, alluvial fan, and colluvial deposits. The results of 230Th-U dating suggest that deposition of the travertines was triggered by large paleoearthquakes in the last eight thousand years. Several stages of travertine formation with ages 9–11 ka BP correspond to the known period of strong paleoseismicity in the region (8–16 ka BP). The 123 ka BP travertine resulted from a slip triggered by the Middle Pleistocene deglaciation, while that of 400 ka BP represents seismic motions likely associated with the main Cenozoic orogenic phase. All travertine forming events fall within warm and wet climatic phases (interglacials). Large earthquakes activated faults and caused a rapid rise along them of ambient-temperature bicarbonate groundwater, which was previously sealed in deep-seated Upper Neoproterozoic–Paleozoic limestone-dolostone aquifers. Rapid CO2 degassing of the spring water was the most important control of calcite or aragonite precipitation. Such travertines represent an important tool for paleoseismological research in seismically active regions.

В статье приводятся предварительные результаты изучения и характеристика проявлений процессов неотектоники в Денисовой пещере, их влияния на формирование и постседиментационные изменения плейстоценовых пещерных отложений. В Денисовой пещере следы палеоземлетрясений рассматриваются в разрезах осадочных толщ центрального зала, восточной и южной галерей. Описаны основные типы сейсмогенных деформаций. Дается хронологическая оценка эпизодов древних сейсмических событий, запечатленных в стратиграфической последовательности пещеры. Установлено, что смещения слоев в результате сейсмических деформаций оказались незначительными, и их границы хорошо коррелируются. Не происходило смешения вещества разных литологических подразделений и соответственно содержащихся в них палеолитических и палеонтологических материалов. Предполагается, что неотектоническая активность могла оказывать влияние на условия обитания первобытного человека как один из факторов природной среды.

The aerial stratotype of the Chibit Glaciation in a stratigraphic chart of Quaternary deposits of the Altai–Sayan Mountains, which corresponds to the Last Glacial Maximum (LGM) or the fourth step of the Upper Neopleistocene of the Russian Stratigraphic Chart, is characterized. The reference geological sections of diamictons of the Chibit Horizon are described and positioned. The geomorphological scheme with contours of the LGM Chibit and Maashei glaciers, which is composed of materials of remote sounding, field geomorphological observations, and geological data, is presented. The boundaries of the ice-dammed Baratal Lake are shown for a flooding level of 1700 m, which corresponds to the upper terraces in the northeastern margin of the Kurai Depression. The boulder gravels, which are deposited as a result of the outburst of Baratal Lake, are found in an old valley of the Chuya River. They compose a terrace body 5–7 m high cut into the Chibit moraine. The latter is embedded into the Saldzhar superflood sequence, thus, the Saldzhar and Baratal outbursts have different ages and scales.

Archaeoseismic studies in the Kurai Fault Zone in southeastern Gorny Altai (Siberia, Russia) reveal signatures of deformation caused by paleoearthquakes to burial and memorial sites (mound, khereksur, stone heap, stone enclosures), megaliths (steles), and irrigation ditch (suvak), which were located at the front of fault scarps or in their vicinity. The seismic motions left numerous traces of deformation: displaced of cairns of mound and khereksur; bending, displacement and rotation of parts of the khereksur's walls; bending stone structures at scarp crests; tilted and rotated enclosure's stone slabs; offset irrigation ditch; the displacement is most often directed. Dating of the archaeological site provides lower age bounds to the earthquakes. They all occurred for the past 3000 years, while the youngest events, similar to 1.2 ka BP and no older than 1000 CE, were located in the northern Kurai and Kokorya basins, respectively. The deformation features in the mounds have bearing on the coseismic slip geometry.

Abstract The Northern West Siberian–South Kara Composite Tectono-Sedimentary Element (NWSSK CTSE) occupies over 1 million km 2 of the northern West Siberian Basin and the South Kara Basin. It formed as a result of the latest Permian–earliest Triassic crustal extension following thermal subsidence. The Early Triassic palaeorifts are buried under 10–12 km-thick post-rift Middle Triassic–Quaternary siliciclastic sediments. In the Tithonian–Early Berriasian period, a deep-water anoxic depression formed in the West Siberian Basin and accumulated the organic-rich carbonate-siliceous Bazhenov shales that are the main source of hydrocarbons. The West Siberian Basin, including the NWSSK CTSE, is one of the major petroleum provinces worldwide. Oil and gas deposits have been identified in Paleozoic carbonate basement rocks and Triassic, Jurassic and Cretaceous reservoirs. The main gas reserves are concentrated in the Lower Aptian–Cenomanian play. Significant gas and oil reserves are located in the Berriasian–lowest Aptian and Jurassic plays. The CTSE comprises 18–20% of the world's known gas reserves and provides approximately 90% of all Russian natural gas, which comprises 22% of global gas extraction. In this chapter we provide a summary of the CTSE geology and petroleum geology based on bulk results published mostly in the Russian literature.

A system of 22 km long surface rupture produced by paleoearthquakes has been mapped for the first time along the Kubadru Fault which delineates the Kokorya Basin in the north. The ruptures morphology record reverse and right-lateral strike-slip geometry of the Kubadru Fault. The ruptures pattern represent a combined effect of four paleoearthquakes, including three events in the past 1.4 kyr. The magnitudes of the earthquakes could range from 6.7 to 7.6. The revealed structure of the Kubadru Fault Zone consists of counter-dipping reverse faults. Motions on two reverse fault systems maintained thrusting of the Kurai Range on the basin sediments and caused the growth of a foreberg between the basin and the range.

Abstract—We studied historical and paleoseismic deformations in the southern Issyk-Kul depression—on the territory of adyrs (piedmonts) of the Terskey Ala-Too range: (1) along the southern foot of the Kokonadyr-Tegerek mountains in the Ala-Bash-Konur-Olen intermountain depression; (2) in the Tossor river basin; (3) in the Chon-Kyzyl-Suu river valley; and (4) on the northern slope of the intradepression adyr uplift of Bir-Bash. We used 21 results of radiocarbon dating of samples taken in the walls of paleoseismological trenches or cleared natural outcrops. These studies in the south of the Issyk-Kul depression revealed 10 strong seismic events during the Holocene. We found that they had migrated from the west—from the Ala-Bash-Konur-Olen depression in the early Holocene eastward—to Mount Bir-Bash (by the beginning of Anno Domini) and then again back—westward to the Kokonadyr-Tegerek foothills (by the end of the Late Middle Ages). Some of the discovered seismic catastrophes may have been the beginning or the end of the evolution of some civilizations in the region (the Andronovo culture and the Karakhanids). The obtained data can be used to make the New Map of Seismic Zoning for the Issyk-Kul Region of the Kyrgyz Republic.