A general assessment of geology of the Lake Baikal basin is given. Issues related to the methodology and main results of studying hydrocarbon migration processes in the central environmental zone of the Baikal natural area from 2015 to 2020 are discussed. Extensive material has been obtained on geology of the upper part of the section of recent sediments, geochemical, physicochemical and other features of the near-bottom area of the lake. An electronic atlas of 1:1M maps of the central ecological zone of the Baikal natural area and an electronic catalogue of hydrocarbon occurrences and their discharge zones were compiled. The high efficiency of combining various geological methods for identifying, studying and monitoring sites of natural hydrocarbon migration is shown.

The lithological map of the Lake Baikal water area bottom at a scale of 1 : 500 000 was first compiled based on results of analysis of materials from previous studies and annual field geological and geophysical surveys, and a set of laboratory studies made at VSEGEI (2015–2020). The paper discusses the genetic typification and patterns of distribution of bottom surface sediments, describes recent sedimentation processes of the lake basin.

A comprehensive geoscientific study of naphthide occurrences on the bed of Lake Baikal has been carried out. It has been established that some of them are unique geological targets. It is proposed to consider such targets as geological heritage sites and grant them an official conservation status.

Results of studying authigenic nodules from the surface bottom sediments in the Southern Basin of Lake Baikal are given. In the P-2 hydrate-bearing structure («Peschanka»), elemental sulphur was found in them for the first time. It is assumed that its formation in nodules is a consequence of incomplete biogenic oxidation of hydrogen sulphide by oxygen.

Information about the cataloging and mapping of hazards on Lake Baikal associated with hydrocarbon migration processes is given. A solution to the problem of user access to results of studies and observations is proposed by developing a special geoportal based on Internet mapping information technologies that provides operational access for state authorities, local governments, organizations and citizens to information on hazards currently existing on Lake Baikal due to hydrocarbon migration processes. Main criteria for choosing technical solutions and the main functionality required for developing the geoportal are given.

The paper discusses new data obtained during mineralogical-petrographic, petrogeochemical, isotope geochronological, and isotope geochemical studies of igneous rocks from the Malmyzh and Gion ore fields. Results of isotope geochronological studies indicate the Late Cretaceous-Cenomanian (97–99 Ma) and Campanian (76–82 Ma) radiological ages of their magmatic crystallization, respectively. Based on a comparative analysis of the studied samples with each other and with igneous rocks from other porphyry deposits of the world, the authors describe results of studying at the secondary ion mass-spectrometer (SIMS) of distribution patterns of trace elements (REE+Y, Hf, Ti, U, Th, Pb) in accessory zircons from igneous rocks of the Malmyzh and Gion ore fields in order to assess their ore potential for gold-copper-porphyry mineralization.