The results of U–Th–Pb (LA-ICP-MS) geochronological studies of detrital zircon (fraction >50 µm) from the Late Cenozoic deposits of the large aeolian “Sands” massif of the Chara Basin in the eastern flank of the Baikal Rift Zone show that they are dominated by detrital zircon aged 263–265 and 1861–1864 Ma. Archean ages have been obtained only for individual zircon grains. This might be due to the fact that zircon of this age is present in “fine” fractions, the study of which is hardly possible due to the technological features of the method of geochronological studies in use. Based on the geological situation, granites of the Kodar Complex can be considered as the sole source of Early Proterozoic detrital zircon. The source of detrital zircon aged 263–265 Ma remains a mystery. Granitoid massifs of this age are not known on the territory of the Aldan Shield. They are widespread in its western margin.

In connection with the recent centennial (2018) of Russian geomorphology, we examined the history of the origin and development of geomorphological knowledge in this country. We analyzed the main stages of the formation of national geomorphology: from the prehistory (17th‒18th centuries) and the incubation period (19th‒early 20th centuries) to an intense development in the Soviet period (most of the 20th century) and the modern stage. We distinguished the main driving forces of this process: the enormous size of the country and the corresponding diversity of landscapes, a high economic need for development of natural resources, and a need for effective systematization of knowledge in the field of Earth sciences. We also emphasized the continuity and close connection of the development of geomorphology in Russia/USSR and in other countries. Particular attention was paid to the Russian geomorphological schools concentrated in major educational and scientific centers in Moscow, St. Petersburg, Irkutsk, Kazan, Tomsk, etc. National researchers of these schools promote important scientific fields, such as structural geomorphology (morphotectonics), climatic (exogenous) geomorphology, geomorphological systematics and cartography, evolutionary geomorphology, morphometry, dynamic and engineering geomorphology, environmental, social geomorphology, etc. Separately, we mentioned the contribution to the Russian geomorphological science by famous scientists: P.A. Kropotkin, V.V. Dokuchaev, D.N. Anuchin, M.M. Tetyaev, Ya.S. Edelstein, I.S. Shchukin, K.K. Markov, S.S. Schulz, I.P. Gerasimov, Yu.A. Meshcheryakov, D.A. Timofeev, O.K. Leontyev, Yu.G. Simonov, N.A. Florensov, G.F. Ufimtsev, A.N. Lastochkin, and many others. Finally, we emphasized that today Russia’s geomorphology has entered a new stage of development corresponding to current world trends: the study of inaccessible terrain (submarine, subglacial, extraterrestrial), digital modeling based on GIS technologies, and integration with other disciplines of the geological and geographical series.

Nikolai Aleksandrovich Florensov is a Russian scientist who is famous for his contribution to the theoretical foundations of structural geomorphology.He formulated the law of the circulation of material in the Earth's crust, which is manifested by a periodically arisinglithodynamicflow, in the development cycle of which two main phases are distinguished as ascending and descending geodynamics. In our opinion, there is also the third phase, stabilization.This process is reflected in the morphological types of mountains. Considering the conditions of intracontinental orogeny, N.A.Florensovdistinguished two main types: constructive and destructive.Developing this concept, he solved a number of theoretical and philosophical problems concerning the inextricable relationship between the relief and the structure of the geological substratum, its geodynamics and, as a consequence, proposed to consider their relationship as changes in geomorphological formations in time and space. The scientific creativity of NA. Florensov, as a whole, is comparable in importance with that of other most prominent geomorphologists of the late 19th and 20th centuries, including V.M. Davis, W. Penk, S.S. Shults, I.P. Gerasimov, and L. King.

Geochronological (LA–ICP–MS) U–Th–Pb studies of detrital zircon of the Late Cenozoic sand deposits on Ol’khon Island have been performed. It has been shown that their main source is represented by Early Paleozoic igneous and metamorphic complexes of the Ol’khon Terrane of the Central-Asian Mobile belt and Late Carboniferous–Early Permian granitoids of the Angara–Vitim batholite. Sands from the source were transported over a distance of no less than 100 km. It is supposed that it was effectuated by strong air flows, over the ice on the Lake Baikal in particular.

We examine the question of determining the place of geomorphology in the system of Earth sciences. The study revealed that, in spite of the differences in understanding the subject matter of science, there are at least seven integrating and generally accepted techniques of geomorphological investigations themselves: orographic analysis, cartometry, remote analysis of hidden landforms, morphometry, geomorphological mapping, modeling of geomorphological systems and conceptual development of the methodology. Emphasis is placed on the important role of geomorphological mapping in understanding all processes on land cover and the history of its development, assessing the natural resources and natural hazards, and in forecasting the evolution of the landscape. The technique of representing results from geomorphological investigations as a geomorphological map requires developing a classification of topographic features and landforms, and publications of A. N. Lastochkin and his followers are specifically focused on this issue. The integrating role of N. A. Florensov's ideas of concepts concerning the continental orogenesis and geomorphological formations is pointed out. The autonomy of geomorphology in the system of Earth sciences is demonstrated but it is emphasized that it is not possible to further develop geomorphological knowledge outside the province of related Earth sciences, primarily geology and physical geography. A substantiation is given to the exclusiveness of the object of study (topography of land cover) and the subject (main topographic properties: morphology, genesis, age, and morphogenesis processes) which can be analyzed solely by geomorphological research techniques and development models.

It has been demonstrated on basis of Sm–Nd isotopic analyses of the Cenozoic sands from the Chara and Tokkin Basins in the eastern flank of the Baikal rift zone that the Chara–Olekma Geoblock of the Aldan Shield is an area of intense crust growing processes occurred not only in the Paleoarchaean but in the Mesoarchaean as well.

We examine the issue concerning the determination of the line of demarcation between geomorphology and the related Earth sciences which is associated with elementarization of continual topographic surface of the planet’s relief. We present our view of the progression along this direction that relies on the theory of the system-morphological foundation of Earth sciences. We established the existence of the synenergy effect in the use of the system-morphological approach in all particular geographical sciences: in microclimatology, it provides a means of referencing microclimates and “local climates” to topographic features; in soil science, it revitalizes the notion of an elementary soil area thus simplifying the process of soil mapping. In geobotany and biogeocenology, this approach helps to make results from studying phytocenose productivity and from dendroindication investigations more representative. We determined a direct practical importance of landscape geophysics and assessments of the significance of geotopes on land surface as well as on the bottom of the World Ocean and beneath mainland glaciers. It is suggested that the system-morphological approach be used in the interests of a further development not only of traditional analytical geomorphology but also its new, synthetic direction that relates geomorphology with social sciences. It is established that in such a case the symmetry tools can be sued to define the relief as the set of locations with anthropogenic objects, processes and phenomena.

Previous geochronological and Sm-Nd isotopegeochemical studies have identified the main stages of the Precambrian continental crust formation in the central and eastern parts of the Aldan Shield [Kotov et al., 2006], while its western part (Chara-Olekma Geoblock) has not been adequately investigated yet in this respect.

The paper briefly runs through the questions of compiling and contents of morphotectonic map and morphotectonic zoning scheme of Northeast Eurasia. The author's approach is based on mapping the difference between highest and lowest altitudes within the cells 20 x 20 km.

Ol'khon block have steps of 350-600, 600-800, 800-1200 m height, Priol'khonsky block have steps of 350-560, 560-600, 600-680, 680-800, 800-1000 m height. These blocks are the dry part of closing dike between Northern and Middle Baikal depressions. The structure of relief is determined by paleoforms of denudation relief, which have persisted since the formation of the oldest (late Cretaceous - Paleogene) transregional and younger (Pliocene) planation surfaces. Since that time no considerable relief transformation have taken place.

Mechanisms of the three types of low hill landscape (LH) are described. LH of watersheds is forming by exhumation processes, which wash out the crust of weathering on the planation surfaces and denude the inequalities of paleo relief. Karst, deflation, sheet wash and pediments formation are important parts of this process. Formation of slope LH is well described in literature. Streamside LH rises due to water erosion under the conditions of little basis changes. Prismatic shape of the hills is its characteristic feature. Selective denudation of heterogeneous substrate complicates all three relief types.

Geomorphologic mapping of the ore field (374 km 2 in area) was fulfilled to scale 1:10 000. The method and technology for such mapping are described. Geoindicators of deep ore-bearing structures were revealed.

Late Mesozoic Aginskaya tectono-magmatic structure was formed in the lower part of brittle earths crust. It has no direct or indirect manifestation in the morphostructure of the region, being localized over TMA zone of NE strike as magmatic focus by the mantle activization. Its ring-shaped morphology and ore zonality were formed by magma differentiation. Its manifestation on space images as lineament pattern occurs due to springtime development of plant communities, which are indicators of small landforms.

The Priolkhonie area is neotectonically neutral block of the Baikal basin. Under the conditions of semiarid climate karst-denudation processes play the important role in its development. Relief structure of Ozersky and Tazheransky areas is thoroughly described. It is conformed completely to the Early Paleozoic substrate structure, but is complicated by three levels of karst-denudation surfaces: low - with absolute heights 600-620 m, middle - 650-680 m, and high - 680-710 m. In Tazheransky area two upper levels merge in the result of recent denudation processes. Stepped relief of the Priolkhonie correlates well with regional patterns of the whole range and basin system of the Pribaikalie.

The relief of depressions and ridges in the alpine type middle mountains of Pribaikal'e was analyzed in the context of N.A. Florensov's concept of geomorphologic formations. Author aimed to develop a new doctrine, which would be able to overcome the one-sidedness of geomorphology.

The concept "cryptomorphic geomorphologic structures" is explained. Their marginal position in the discreet morphotectonic sequence is determined as well as their origin dew to dissipation of deep mantle energy and the possibility of their coexistence together with morphostructures within mutual geomorphologic space. Some examples of cryptomorphic lithospheric structures are given; their dynamics and the use of the information about them in practical purposes are discussed.

Structural-geomorphologic indicators of the covered stocks in poorly exposed areas are very important for rare metal ore-bearing stocks prospecting. Orlovsko-Spokoinenski ore field in the northern sector of the outer zone of the Aginsk Late Mesozoic macrostructural form with a central-type symmetry was taken as a test site. At the first stage investigation of exogenic processes was fulfilled. Creep, sheet wash and linear erosion are the main processes in the area, especially intense during heavy rains. Cryogenic processes like solifluction and congelifluction are of some importance too.