Southern East Siberia Pliocene-Quaternary faults:Database,analysis and inference

Abstract This paper presents the first release of an Informational System (IS) devoted to the systematic collection of all available data relating to Pliocene–Quaternary faults in southern East Siberia, their critical analysis and their seismotectonic parameterization. The final goal of this project is to form a new base for improving the assessment of seismic hazard and other natural processes associated with crustal deformation. The presented IS has been exploited to create a relational database of active and conditionally active faults in southern East Siberia (between 100°–114° E and 50°–57° N) whose central sector is characterized by the highly seismic Baikal rift zone. The information within the database for each fault segment is organized as distinct but intercorrelated sections (tables, texts and pictures, etc.) and can be easily visualized as HTML pages in offline browsing. The preliminary version of the database distributed free on disk already highlights the general fault pattern showing that the Holocene and historical activity is quite uniform and dominated by NE–SW and nearly E–W trending faults; the former with a prevailing dip-slip normal kinematics, while the latter structures are left-lateral strike-slip and oblique-slip (with different proportion of left-lateral and normal fault slip components). These faults are mainly concentrated along the borders of the rift basins and are the main sources of moderate-to-strong (M ≥ 5.5) earthquakes on the southern sectors of East Siberia in recent times. As a whole, based on analyzing the diverse fault kinematics and their variable spatial distribution with respect to the overall pattern of the tectonic structures formed and/or activated during the late Pliocene–Quaternary, we conclude they were generated under a regional stress field mainly characterized by a relatively uniform NW–SE tension, but strongly influenced by the irregular hard boundary of the old Siberian craton. The obtained inferences are in an agreement with the existing models of the development of the Baikal region

Numerical modeling of phase-separation in binary media based on the cahn-hilliard equation

In the article numerical procedure for solution of the Cahn-Hilliard equation which is based on the forward Euler method in time and mixed (due to 4th order nature of differential operator) linear finite element formulation in space is described. Numerical examples consist of idealized model with double well potential (in 2 and 3 spatial dimensions) and more physically relevant model with logarithmic potential (in 2D only).У статті описано процедуру наближеного рішення рівняння Кана-Хіллярда в частинних похідних 4-го порядку, котра базується на явному методі Ейлера в часі та змішаній постановці з білінійними скінченими елементами в просторі. Наведено чисельні рішення для ідеалізованої моделі з двуямним потенціалом (в 2-х та 3-х просторових вимірах) та більш фізично релевантної моделі з логарифмічним потенціалом (тільки в 2-х просторових вимірах)

КОМПЛЕКСНЫЙ ПОДХОД К ВЫБОРУ МЕТОДОВ ОЦЕНИBАНИЯ ИТ-ПРОЕКТОВ

An integrated approach to the choice of methods of evaluation of it projectsThe integrated approach of a choice of methods for estimation of IT projects taking into account a set of methods, parameters and criterion of their choice depending on specific conditions of implementation of projects is presented in the article.В статье представлен комплексный подход выбора методов для проведения оценивания ИТ-проектов с учетом набора методов, параметров и критерия их выбора в зависимости от конкретных условий реализации проектов

SEISMITES OF THE SOUTHERN EAST SIBERIA: RESEARCH PROBLEMS AND PERSPECTIVES

The article reviews research problems and perspectives of studying the secondary seismogenic deformations of vibrational type (termed «seismites») that are revealed in soft sediments in the territory of the Southern East Siberia. Proposed are ways and principles based on which criteria can be developed for definition of similar structures in view of wide propagation of cryogenic processes. Studies to reveal seismites in cross-sections of the Selenga river delta, the Tunka basin and the southern part of the Siberian platform have been conducted; some of the research results are presented in the article

Cost-effectiveness analysis of pembrolizumab versus targeted therapies in advanced melanoma

Background. The modern therapies of advanced melanoma include targeted medicines for patients with BRAF mutations. Nowadays, a new perspective on immuno-oncologic medicine pembolizumab became available in Russia. Objective. Assessment of the clinical and economic effectiveness of the use of pembolizumab in the treatment of unrespectable and metastatic melanoma in comparison with targeted medicines in the context of Russian public health. Materials and methods. The Markov model was developed, including the states «without progression», «after progression» and «death», the duration of one Markov cycle is 1 month, the modeling time horizon is 5 years. The probabilities of transitions between states were described using mathematical formulas obtained as a result of digitization and approximation of Kaplan-Mayer survival curves, which were derived from randomized clinical trials KEYNOTE-006, COMBI-v and COMBI-d. Direct medical costs (including drug costs, treatment of adverse events, second-line therapy after disease progression, and palliative care) were analyzed. We did not take into account the costs associated with laboratory-diagnostic procedures and visits to the doctor. The sources of information were: weighted average prices of medicines indicated during public procurement for 2016 (the price of the drug pembolizumab provided by the manufacturer), a program of state guarantees for providing free medical care to Russian citizens for 2016, federal coefficients of relative costs for clinical and statistical groups. The effectiveness criterion for cost-effectiveness analysis was the average number of saved months of a patient’s life. Results. The average number of months saved was 30, 23, 24 and 30 months with pembolizumab, vemurafenib, dabrafenib and dabrafenib plus tramethanib, respectively (calculated using the developed model). Thus, pembolizumab has the same effectiveness as a combination of dabrafenib + tramethanib and is more effective than monotherapy with targeted drugs (dabrafenib or vemurafenib). Direct medical costs per patient over 5 years were approximately 4.06, 5.53, 5.91 and 15.72 million rubles when using pembolizumab, dabrafenib, vemurafenib and a combination of dabrafenib + trametinib, respectively. The health budget saving with pembolizumab instead of dabrafenib, vemurafenib and dabrafenib + trametinib combination may be 26%, 31% and 74%, respectively. Conclusion. Pembolizumab is a rational and economically justified choice for the treatment of unresectable and metastatic melanoma since it leads to cost savings when overall survival is increased

СРЕДНЕКЕДРОВАЯ ПАЛЕОСЕЙСМОДИСЛОКАЦИЯ В БАЙКАЛЬСКОМ ХРЕБТЕ: СТРУКТУРА И ОЦЕНКА СМЕЩЕНИЙ ПО ДАННЫМ ГЕОРАДИОЛОКАЦИИ

Our study aimed to clarify the seismic potential of the Severobaikalsk fault and to discover the structural features of active faults on the NW shores of Lake Baikal. Seismogenic faults and large seismogravitational structures were mapped in the area of the Srednekedrovaya paleoseismodislocation, one of the most remarkable seismotectonic structures in the Baikal region. During the field trip, we tested the capacities of an OKO‐2 georadar and an ABDL‐ Triton antenna used to study cross‐sections of the Baikal ridge. Its slopes are steep, covered with Pinus pumila and abundant screes, many of which developed into boulder streams (‘kurumnik’). The first studies of the Sredneked‐ rovaya paleoseismodislocation were conducted by V.P. Solonenko and his team in 1964–1965. To some extent, this zone can be viewed as a reference object that can provide much information and thus deserves an in‐depth investiga‐ tion using new technologies. Our study combined the field observation and the interpretation of high‐resolution satel‐ lite images provided by DigitalGlobe (US) and downloaded by SAS.Planet. The consolidated database was sufficient for constructing a new schematic map showing the seismogenic faults associated with the Srednekedrovaya paleoseis‐ modislocation. The cumulative length of the ruptures observed on the surface amounted to almost 29.5 km. Some ruptures are separate from each other, and the rupture spacing ranges from the first tens of meters to the first kilome‐ ters. The width of the widest rupture zone is 1.9 km. The length of individual ruptures varies from 5.0 m to 2.7 km. Morphologically, the Srednekedrovaya paleoseismodislocation is represented by ledges and ditches that often comprise complex grabens disturbing the bedrock and slope deposits. The fault structure of this zone is a typical set‐ ting of orthogonal and slightly oblique crustal stretching, but its manifestation differs in the zone segments. In general, it is a combination of steeply dipping and listric faults traced to the depth of 13 m. In plan, the faults are observed to form the systems of subparallel ruptures that mainly strike at 30°. A linear relationship is established between the heights of the seismogenic ledges and the throws estimated from the ground‐penetrating radar data. The former are larger by 0.5–2.0 m than the throw measured from the radargrams. Apparently, this reflects the magnitude of expan‐ sion of the ledge upward along the sloping slope. In the zone of the main fault plane coinciding with the main ledge, the maximum and mean arithmetic throws are 8.3 and 4.93 m, respectively. On other fault planes, the throws range from 0.4 to 4.6 m. The paleoearthquake magnitude ranges from 6.8 to 7.6, according to the estimations from the seis‐ mic rock collapse volume, fault length, and the displacements. Our study of the Srednekedrovaya paleoseismodisloca‐ tion confirms that listric normal faulting is widespread along the western side of the North Baikal basin and gives in‐ direct evidence that conditions for accumulation and release of seismic energy are different on the western and east‐ ern shores of Lake Baikal. It should be noted, however, that in the studied near‐surface layer of the crust, the blocks of loose material may move along the flat planes due to gravitational sliding that increases under the impact of cryogenic processes on the steep slopes of the Baikal ridge.Для уточнения сейсмического потенциала Северобайкальского разлома и выявления особенностей строения активных нарушений северо‐западного побережья озера Байкал нами проведено картирование сейсмогенных разрывов и крупных сейсмогравитационных проявлений в районе Среднекедровой палеосейсмодислокации – одной из самых примечательных сейсмотектонических структур в Байкальском регионе. Одновременно мы испытывали возможности применения георадара ОКО‐2 с антенным блоком АБДЛ Тритон для изучения разрезов в условиях крутых склонов Байкальского хребта, покрытых стланиковыми соснами и осыпями, значительная часть которых преобразована в курумники. Впервые изученная в 1964–1965 гг. под руководством В.П. Солоненко Среднекедровая палеосейсмодислокация стала в некоторой степени эталонным объектом, который в силу своей выразительности требует более тщательного изучения в связи с новыми методическими возможностями. В результате выполненных работ нами на основе полевых наблюдений и дешифрирования спутниковых снимков высокого разрешения, предоставляемых американской компанией DigitalGlobe и доступных через программу SAS.Планета, составлена новая схема сейсмогенных нарушений, ассоциированных с палеосейсмодислокацией Среднекедровой. Общая протяженность видимых на поверхности разрывов составила не менее 29.5 км. Некоторые из них отстоят друг от друга на расстоянии от первых десятков метров до первых километров. Наибольшая ширина зоны разрывов составляет 1.9 км. Длина отдельных трещин изменяется от 5 м до 2.7 км. Морфологически Среднекедровая палеосейсмодислокация представлена уступами и рвами, нередко формирующими сложные грабены, которые нарушают коренные породы и склоновые отложения. Разломная структура зоны типична для обстановки ортогонального или чуть косого растяжения, но по‐разному проявляется на отдельных ее сегментах. В целом для нее характерно сочетание крутопадающих и листрических сбросов, прослеженных до глубины 13 м. В плане они образуют системы субпараллельных разрывов с преобладающим простиранием 30°. Полученные высоты сейсмогенных уступов и вертикальные смещения по данным георадиолокации линейно связаны между собой. Значения первых больше величин подвижек, измеренных на радарограммах, на 0.5–2.0 м, что отражает, по‐видимому, величину расширения уступа вверх по осыпному склону. Максимальная и средняя арифметическая вертикальные амплитуды сброса по зоне главного сместителя, совпадающей с главным уступом, имеют значения 8.3 и 4.93 м, соответственно. По отдельным сместителям смещения колеблются от 0.4 до 4.6 м. Оценки магнитуд палеоземлетрясения, рассчитанные по разным зависимостям с использованием объема сейсмообвала, длины разрыва и смещений, колеблются от 6.8 до 7.6. Изучение Среднекедровой палеосейсмодислокации подтвердило, что листрическое сбросообразование широко распространено вдоль западного борта Северобайкальской впадины, что является косвенным свидетельством различных условий накопления и реализации сейсмической энергии на западном и восточном побережье озера Байкал. В то же время в изученном близповерхностном слое земной коры некоторый вклад в движение блоков рыхлого материала по пологим плоскостям может вносить гравитационное скольжение, которое усиливается под воздействием криогенных процессов в условиях крутых склонов Байкальского хребта

TECTONOPHYSICAL EVIDENCES OF GEODYNAMIC EVOLUTION OF THE PRIKOLYMA TERRAIN (NORTH-EASTERN REGIONS OF RUSSIA)

The Prikolyma terrain is a part of the Yana-Kolyma orogenic belt located in the North Eastern Asia. It is generally composed of the Proterozoic deposits, including sandstones, metapellites, quartz-feldspar and carbonate rocks, meta- and hyperbasites. The Prikolyma terrain represents a fragment of passive margin of the North-Asian craton that was detached in the Middle Paleozoic due to progressing rifting. Subsequent geological development of the terrain was determined by accretion events at its boundary with margin of the North-Asian craton and the Omolon microcraton. Its longterm geodynamic evolution is reflected in the character and sequence of formation of the Prikolyma terrain deformation structures. In the central part of the Prikolyma terrain, i.e. in the basin of the Malaya Stolbovaya river, two reference areas of tectonics were studied, which contain packs of thrust sheets complicated by subsequent highangle faults.The fault pattern is complex, and its major elements are gently dipping zones of plastic deformation, which mark the boundaries of petrographically heterogenous plates. The thrust packs  are more than 200 m thick; their root zones are represented by series of highangle reverse faults. Another important element of the fault pattern is highangle zones of brittle deformation, which kinematic characteristics are ambiguous. A vertical component of displacement is predominant for the faults of the north-western strike; a strike-slip component is characteristic of latitudinal and meridional faults. The fault pattern developed in several stages under the impact of fields of tectonic stress, which vectors were variable. The folds, comprising a uniform structural paragenesis with thrusts, are of great importance for the structure under study. The largest folds exhibit the asymmetric structure with the N-E dipping axial planes. Axes of smaller folds are oriented to N-W and N–NW.Four stages of deformation are distinguished in the history of geological development of the Prikolyma terrain. The earliest stage was characterized by the N-E compression resulting in formation of the N-W-oriented thrusts and folds and zones of greenschiest dynamo-metamorphism. During the second stage, the axis of compression gained the E–NE orientation, and the axis of extension was oriented to the N–NW, which influenced the formation of the submeridional reverse faults and thrusts. During the third stage, the axis of compression was N-W oriented, and the axis of extension gained the N-E orientation. Thereat, the sublatitudinal and submeridional structures were activated as strike-slip faults, the N-W structures as normal faults, and the N-E structures as reverse faults. The above resulted in the formation of structures of volume extension, which are favorable for localization of magmatic bodies and ore streaky-veined structures. At the final stage, compression in the meridional direction lead to the formation of thrusts and reverse faults along the sublatitudinal displacements, normal faults along the submeridional displacements, and strike-slips along the N-E and NW displacements.The first deformation stage was contemporaneous with the long-term period of compression in the Riphean and Early Paleozoic, when the dynamo-metamorphic complex of the Prikolyma terrain was developed. In the second stage, the Prikolyma terrain was detached from the margin of the North-Asian craton. In the Early Cretaceous, the third stage took place, when rearrangements of the field of tectonic stresses and transition to conditions of general extension caused emplacement of granitoids and quartz veining. The N-W orientation of the compression vector suggests that the third stage was related to the regional tangential compression due to the asymmetrical collision of the Prikolyma terrain and the Omolon microcraton. In the final stage, rotation of the vector of compression, associated with development of numerous N-W and N-E-oriented fractures, reflected the occurrence of the epiorogenic rifting. The above-described stages of formation of the deformation structure of the Prikolyma terrain are evidently correlated with the main tectono-magmatic stages of development of the NE margin of the North-Asian craton, which took place in the Late Paleozoic and the Mesozoic

СЕЙСМИТЫ ЮГА ВОСТОЧНОЙ СИБИРИ: ПРОБЛЕМЫ И ПЕРСПЕКТИВЫ ИЗУЧЕНИЯ

The article reviews research problems and perspectives of studying the secondary seismogenic deformations of vibrational type (termed «seismites») that are revealed in soft sediments in the territory of the Southern East Siberia. Proposed are ways and principles based on which criteria can be developed for definition of similar structures in view of wide propagation of cryogenic processes. Studies to reveal seismites in cross-sections of the Selenga river delta, the Tunka basin and the southern part of the Siberian platform have been conducted; some of the research results are presented in the article.В статье рассматриваются проблемы и перспективы исследований вторичных сейсмогенных деформаций вибрационного типа (сейсмитов) в рыхлых отложениях на территории юга Восточной Сибири. Предложены пути и принципы разработки критериев выделения подобных структур на фоне широкого развития криогенных процессов. Приведены результаты изучения разрезов, содержащих сейсмиты на различных площадях (дельта р. Селенги, Тункинская долина и юг Сибирской платформы)

ДИНАМИЧЕСКАЯ ФИЗИКО-ГЕОЛОГИЧЕСКАЯ МОДЕЛЬ МЕСТОРОЖДЕНИЯ АЛМАЗОВ КИМБЕРЛИТОВОЙ ТРУБКИ КОМСОМОЛЬСКАЯ (АЛАКИТ-МАРХИНСКОЕ ПОЛЕ ЗАПАДНОЙ ЯКУТИИ)

Petrophysical, tectonophysical and paleomagnetic studies were done on the field of diamonds from the Komsomolskaya kimberlite pipe to interpret the observed gravimagnetic field. As a result of studying the structural-material complexes (SMC) of the field, there was formed a dynamic physical-geological model (DPhGM). The structure of the deposit is a dynamically developing network of faults that control heterochronous igneous complexes (kimberlites and traps). The features of the tectonic structure and physical properties of the SMC of the field were reflected in the nature of the observed gravitational and magnetic fields. DPhGM provides proofs for the existence of geophysical anomalies, genetically related to the structures of diatreme association – anomalies of the structural type.В пределах месторождения алмазов Комсомольская проведены петрофизические, тектонофизические и палеомагнитные исследования с целью интерпретации наблюденного гравимагнитного поля. В результате изучения структурно-вещественных комплексов (СВК) месторождения сформирована динамическая физико-геологическая модель (ДФГМ). Структура месторождения представляет собой динамически развивающуюся сеть разрывных нарушений, которые контролируют разновозрастные магматические комплексы (кимберлиты и траппы). Особенности тектонического строения и физических свойств СВК месторождения отразились на характере наблюденных гравитационного и магнитного полей. На основе ДФГМ доказано существование геофизических аномалий, генетически связанных со структурами диатремовой ассоциации, – аномалий структурного типа