The name of the famous geologist and teacher Alexander Vladimirovich Lvov (1871-1941) is well known not only to specialists, but also to all those interested in the history of scientific research in Siberia. Lvov stood at the origins of geological education in Irkutsk, created a scientific school of engineering geology and permafrost science in Siberia, participated in the study of minerals of the Baikal region and mining conditions of the construction and operation of the Trans-Siberian Railway. One of his research areas was participation in surveying sites for the construction of hydroelectric power plants in Priangarie.

The special issue of the journal is devoted to the researchers and history of geological exploration in Eastern Siberia. The articles of the issue emphasize the initial contribution to the study of geology, geography and minerals of the territory by A.V. Lvov and S.P. Peretolchin and V.M. Senyukov, N.A. Florensov, V.P. Solonenko, V.D. Mats and others, information about the unknown pages of the Circum-Baikal railroad construction, the study of the Botogol graphite field, the Markovskoye oil and gas condensate field, the Baikal depression system and the volcanism spatially related to its formation is given. A review of 50 years of labor activity of geologists-graduates of IGU in 1973 is given.

The survey work, construction and operation of the railroad from Irkutsk along the southern shore of Lake Baikal were accompanied by detailed geological studies. During several field seasons during the surveys all projected directions of the railroad were studied. As a result, it was recommended to build a railroad from the source of Angara to Mysovoye village along the shore of Lake Baikal. But the results turned out to be too optimistic. During the development of rocky slopes from the source of the Angara River to Kultuk, intensive rockfalls began, which continued during the operation of the line, causing new surveys of the entire section. In the vicinity of Mysovoye village, the identified ancient landslides caused additional study of the geological structure of the area and drainage works.

The Botogol graphite deposit, located in the Eastern Sayan Mountains, is of interest not only because of its rich ores, but also because of the rich history of its study. Since the discovery of graphite manifestations on the Botogol mountain in the first half of the 19th century, the study of its structure and genesis has been underway. It took more than a century of prospecting and exploration and exploitation works to get an idea of the geology of this deposit. The history of the study of this unique deposit is considered in the article.

The article gives a comparative analysis of the achievements of natural-scientific research of glaciers in the area of Munku-Sardyk (Eastern Sayan Mountains) in the early XX century of the famous Irkutsk geologist, geographer and climatologist Sergey Pavlovich Peretolchin (1863-1914) in comparison with modern geographical research of the authors of the article in the early XXI century.

The history of the discovery of the first oil and gas fields on the Siberian platform is traced from the first oil deposit in the Chemikanskaya area in the Tolba River basin (Sakha-Yakutia) to the discovery of the first Markovskoye oil and gas condensate field. The role of the father of Siberian oil Vasily Mikhailovich Senyukov in obtaining the first oil on the Siberian platform and in promoting the idea of support drilling within its boundaries is shown. Despite the accidental discovery of the Markovskoye field (oil fountain) in 1962, exploration work within its boundaries indicated a further direction of prospecting in the northern direction 90 km from Markovo (within the Nepsky vault).

Meetings of alumni of different universities are frequent. Geology graduates meet especially regularly every 5 years. Each meeting is the joy of returning to their youth. Many graduates have long been called by name and patronymic. Although in 50 years meet ... grandparents, each other are called only by their first names. Such a meeting is not just socializing, but also summarizing. Each course carries invaluable work experience in its field. A review of this labor activity shows how much the graduates-geologists have done for the country. Not only representatives of Irkutsk State University and students, but also a wide range of readers should know about it.

The history of the development of ideas about the structure and development of the Baikal system of uplifts and depressions and its most important structural elements is conditionally divided into the following stages: 1) initial hypotheses, which appeared before the 1960s, 2) basic hypotheses related to the large amount of work done in connection with the development of the riftogenesis problem in the south of Eastern Siberia in the 1960s-1990s, and 3) the latest hypotheses based on the facts obtained through the use of new approaches realized in geological studies in the 2000-2020s.

The history of studying and dating the latest volcanism of the Baikal Rift System (BRS) is conventionally divided into stages: 1) before 1950s (discovery of young volcanoes), 2) 1950-1960s (primary determination of the age of Cenozoic volcanogenic-sedimentary strata based on paleontological data), 3) 1970-1980s (determination of the sequence of formation of volcanic strata in the development of the relief and the formation of the relief and the formation of the volcanic strata), and 3) 1970-1980s (determination of the age of the Cenozoic volcanic-sedimentary strata based on paleontological data). (determination of the sequence of formation of volcanic strata in the development of relief and obtaining the first radioisotope data on the age of volcanic rocks), 4) 1980-2005 (accumulation of geochronometric and geochemical data on volcanic areas of Asia), and 5) 2005-2023 (synthesis of geochronometric and geochemical data). The result of the breakthrough in the study and dating of the latest volcanism of the BRS was the substantiation of the conditions of development of mantle melt anomalies in the Japan-Baikal geodynamic corridor (JBGC) and in its overlap with the Indo-Asian convergence area. The breakthrough in the dating of volcanic rocks, formalized by 2012, in the territory of Central Mongolia was mainly confirmed by the mass ³⁹Ar/⁴⁰Ar dated 2018.

Four periods of geological study and development of the southeastern part of the Eastern Sayan are considered. Significant, but scattered study allows us to speak about positive prospects of the area, while maintaining a high potential for discovery of new interesting industrial gold objects.

Four periods of geological study and development of the southeastern part of the Eastern Sayan are considered. Significant, but scattered study allows us to speak about positive prospects of the area, while maintaining a high potential for discovery of new interesting industrial gold objects.