Pacific-type convergent boundaries are both the main formation sites of the juvenile crust of the Earth and the place of its destruction, while subduction zones are the only method of delivery of materials of the continental and oceanic crust that are destroyed on the surface of the mantle. The decryption of the evolution of the parameters of subduction zones of the past can be conducted in the most correct way on the basis of a model of ocean plate stratigraphy (OPS) that can reliably indicate the direction of subduction and allows to determine the size and the age of the plate that existed earlier. Decrypting the processes of the formation of new continental crust by accretion and island-arc juvenile magmatism and its destruction on convergent boundaries can provide information on the type (accretional or erosional) and the geometry (orthogonal or oblique subduction or transform boundary) of the active plate boundary. The diagnostics of Pacific-type convergent boundaries as part of ancient fold belts is important for global geodynamic, tectonic, and palaeogeographic reconstructions and for seeking and exploring mineral deposits.
Of all the materials that can be subducted into the mantle, the most important are water, carbonates, serpantinites, and basalts of the oceanic slab and volcanic arc rock, especially sialitic. Materials eroded on Pacific-type convergent boundaries and subducted into the mantle can accumulate in the transitional zone and initiate the generation of hydrocarbonate plumes at depths of 410 to 660 km. Pacific-type orogeny links the model of ocean plate stratigraphy (OPS), the parameters of Pacific-type convergent boundaries, and the model of shallow hydrocarbonate mantle plumes. The study of the latter is necessary for the justification of the relation between periods of subduction, accretion and tectonic erosion with plume initiation in the transitional zone of the mantle and their manifestations on the surface of the Earth in the form of intra-plate magmatism.
Implemented results of research:
- The Laboratory has obtained the patent No. 2667329 for «A method for the geological mapping of accretionary complexes». The invention belongs to the field of the reconstruction of geological processes in the development of the Earth's crust on the basis of thorough large-scale mapping and the geochronological and lithological study of accretionary complexes with intricate structures (initial number of the application 2017144982 of 20 December 2017). The objective is to avoid errors when mapping accretion complexes with complicated structures that are part of Pacific-type fold belts. This is especially important since these orogenes are related to a large number of mineral deposits whose discovery and exploration directly depends on the quality of mapping (http://lepom.nsu.ru/pages/Patents_rus.php). Now we are working to implement these developments in practice by conducting negotiations with potential customers (https://www.ipi-singapore.org/tech-offers/174142/geological-mapping-via-ocean-plate-stratigraphy-model-for-exploration-cost-reductions.html ).
- At the Laboratory's sample preparation centre, we have developed three methods of sample preparation for high-precision analytical research and implemented them in practice: 1) a method for the extraction of heavy fraction minerals using a non-toxic heavy fluid, sodium polytungstate. 2) a method for the separation of zirconia using UV lighting. 3) A method for the preparation of zirconium samples on the basis of acrylic resin. These methods are used by all the researchers of the Laboratory and partner institutes for sample preparation and analytical work while conducting scientific research. Undergraduate and postgraduate students also use the methods for their theses. A methodological guidebook on sample preparation has been published (Kotler, 2019 http://lepom.nsu.ru/documents/monograph_Kotler.pdf ).
Education and career development:
Lecture courses:
- «Geochemistry» (Olga M. Tourkina), the Faculty of Geology and Geophysics of the Novosibirsk State University.
- «Introduction to geochemistry» (Dmitriy A. Zedgenizov), the Faculty of Geology and Geophysics of the Novosibirsk State University.
- «Preparation of publications for international journals» (Inna Yu. Safonova ), the Sobolev Institute of Geology and Mineralogy, the Trofimuk Institute of Petroleum Geology and Geophysics of the Siberian Branch of the Russian Academy of Sciences.
- «Palaeogeography and palaeoecology » (Sergey K. Krivonogov), Kyzylorda University (Kazakhstan).
3 bachelor's degree these, 4 master's degree dissertations, 3 Candidate of Science dissertations, one Doctor of Science dissertations.
Organizational and structural changes:
On the grounds of the Laboratory for Palaeocene and Mantle Magnetism, the Sample Preparation Centre (SPC) has been created. In the future we are planning to develop the SPC and to register it as a centre for the collective use of scientific equipment.
Other results:
The work of the laboratory is currently funded by the following projects:
- RSF No. 21-77-20022 Subduction erosion on convergent boundaries of the Palaeo-Asian ocean according to data from the study of accretion and subduction complexes of the Central Asian fold belt, supervised by Inna Yu. Safonova (2021 — 2024).
- RSF No. 20-77-10051 in the competition «Study by research groups under the supervision of young scientists», topic: «The reconstruction of the early to middle Palaeozoic evolution of the Palaeo-Asian ocean on the basis of a complex research of accretion complexes of the Central Asian fold belt», supervised by Ilya A. Savinskiy (2020 — 2023).
- RFBR No. 20-35-90091 «Sources and the tectonic situations of the formation of sandstone from Palaeozoic accretion complexes of the Palaeo-Asian ocean according to geochemistry and zirconometry data», supervised by Inna Yu. Safonova (2020 — 2022).
- Ministry of Education and Science of the Republic of Kazakhstan, project No. АР08855920 «The prospects of the discovery of a copper-nickel province in Central Kazakhstan», co-supervised on the Russian side by Inna Yu. Safonova.
Collaborations:
- Natural History Museum (United Kingdom): joint research (the study of tectonic erosion).
- Institute of the Earth's Crust of the Siberian Branch of the Russian Academy of Sciences (Russia), Institute of Geochemistry of the Siberian Branch of the Russian Academy of Sciences (Russia), Geological Institute of the Kola Science Center of the Russian Academy of Sciences (Russia): joint research (analytical work).
- Trofimuk Institute of Petroleum Geology and Geophysics of the Siberian Branch of the Russian Academy of Sciences (Russia), Saint Petersburg State University (Russia), Far East Geological Institute of the Far Eastern Branch of the Russian Academy of Science (Russia), Institute of Tectonics and Geophysics of the Far Eastern Branch of the Russian Academy of Science (Russia), Institute of Mineral Resources of the State Committee for Geology and Mineral Resources (Uzbekistan), Institute of Palaeontology and Geology of the Mongolian Academy of Sciences (Mongolia): joint publications, field work.
- University of Tokyo (Japan), German Research Centre for Geosciences – GFZ Potsdam (Germany), Okayama University of Science (Japan): joint research and publications, analytical work.
- Institute of Comprehensive Exploitation of Mineral Resources (Kazakhstan): joint research, R&D agreement, joint publications and field work.
- Institute of Geology and Mineralogy of the Siberian Branch of the Russian Academy of Sciences (Russia), University of Hong Kong (China PR): joint publications, field work, analytical work.
- Nanjing University (China PR): joint publications, grants, field work, analytical work.
- Tohoku University (Japan): joint staging of a scientific session at an international conference.
