The laboratory studies geodynamic, geotectonic and geological factors affecting the location of endogenic mineralization, identification of its new geological-genetic types, and improving prediction and assessment of mineral resources in the East Asia.
The investigations are carried out in the following directions:
geodynamic, geotectonic and geological factors affecting the location of endogenic mineralization;
mineral and geochemical features of mineragenic, geological and morphological types of mineralization and its zoning;
isotopic-geochemical characteristics of vein and ore minerals from different genetic types deposits;
composition features of native and minor elements in placer and ore systems of the East Asia;
search and valuation criteria of gold, silver and platinum mineralization;
reveal of new geological genetic and commercial types of mineralization;
improving methods of prediction and assessment of different types of mineralization, using Earth's remote sensing technologies.
Main scientific achievements:
The Southeast Trans-Baikal region in Russia hosts large and super-large Mesozoic polymetallic mineral deposits including chalcophile, lithophile, rare-metal, rare-earth elements and uranium. Here we analyse the salient features of this metallogenic belt in terms of their distribution, mineral speciation and relation to regional structures. The deep mantle architecture beneath this region is analyzed from published geophysical data including seismic tomography. The results show that the highly productive ores are largely located above the axial line of an undulating Moho that projects from the apex region of a subducted slab stagnant in the mantle transition zone. We propose thermal and fluid flux from the asthenospheric mantle, metasomatism of the overlying shallow mantle and mantle-crust interaction that intensified the magmatism associated with metallogeny. Our study provides an example for deep-seated geodynamics influencing the formation and distribution of giant ore belts..
Vadim G. Khomich, Natalia G. Boriskina and M. Santosh. Super large mineral deposits and deep mantle dynamics: The scenario from Southeast Trans-Baikal region, Russia // Geological Journal. 2018. V. 53. Is. 1. P. 412-423. DOI: https://doi.org/10.1002/gj.2908
A unique gold-platinoid-cinnabar mineralization (pic. a, b, c) was found in the black-shale rocks of the South of the Far East. Gold-platinoid-graphite- bearing deposits of the Ruzhino area (Central Primorye) were discovered and studied at the macro- micro- and nano levels. New technological methods of extracting useful components for sustainable complex use of man-made formations and also carboniferous rocks (ecologically accepted and economically efficient methods) have been suggested.
We have improved the standards of evaluation of prospectivity of underexplored territories for determination of endogenous precious metal mineralization of different formation type on the basis of research into geologically geophysical positions, structure, development staging and correlations of orogenic magmatism with occurrence of gold ore-loosen districts of margins of the Northern-Asian craton.
For the first time there has been suggested qualified solution of the problem of synchronous formation in Early Cretaceous of super large gold-ore districts of East Asia – Aldan (South Yakutia), Bailey (Transbaikal) and Zhao-Ye (province of Jiaodong in China), which are remoted from each other over thousands kilometers. There have been made an explanation of influence of deep-sitting geodynamics on formation of high-yield ore-magmatic systems, as a consequence of their placement over front and flank borders of stagnating oceanic slab in transitional mantle zone.
Khomich, V.G., Boriskina, N.G., Santosh M. A geodynamic perspective of world-class gold deposits in East Asia // Gondwana Research, 2014. V. 26. Is. 3-4. P.816-833. DOI: 10.1016/j.gr.2014.05.007.
As a result of synthesizing geological, geophysical, geochemical and mineralogical materials it has been stated that conditions contributing to genesis of platinum-bearing formations are predetermined, in general, with ore-parent magmatism. Ore-parent magmatism attaches conditions for appearance of laminated (in Neoarchean and Proterozoic) and zonal (Phanerozoic) ultramaffit-maffit massifs, which are affected later by ore-forming magmatogenic-fluid-metasomatic processes. More optimum conditions for concentration of PGE were created in the areas where late granitogenic formations applied on before appeared laminated zonal massifs, ophiolite complexes and stratified carbonic terranes.
Khomich V.G., Boriskina N.G. Localization of PGE mineralization in southeastern Russia // Russian Geology and Geophysics, 2014. V. 55. № 7. P. 842–853. DOI: 10.1016/j.rgg.2014.06.004
It has been proved that the first reason of Late Mesozoic tectonic-magmatic and mineragenic activated processes on the Precambrian Aldan shield was appearance of stagnating oceanic slab in transitional mantle zone. Influence of deep-laid geodynamics on genesis of young (J3-K1) magmatic-metalogenetic belt here appeared through dehydration of slab rocks, advection and upwelling of fluids. They assisted implication of derivatives of lower mantle into rising uppermantle streams (plumes) and formation (especially on the edges of slab) of productive ore-magmatic systems on PGE, Au and U, before considered as Diwa structures.
Khomich V.G., Boriskina N.G., Santosh M. Geodynamics of late Mesozoic PGE, Au, and U mineralization in the Aldan shield, North Asian Craton // Ore Geology Reviews. 2015. V. 68. P. 30-42. doi:10.1016/j.oregeorev.2015.01.007.
The method of prognostic evaluation of mineralized areas of ore-field scale with remote emphasizing of structured patterns has been programmed for searching for possible ways of migration of elements. In presence of geochemical barriers they are able to form the zones where mineralization is accumulated. On the example of Nizhne-Taezhny ore cluster of North Primorye, paleo hydrothermal system has been reconstructed through the level of permeability with the split of infrastructure. Based on interpretation of position of known ore bodies this let us to emphasize the prospective section where before an unknown mineralized zone can be probably found.
Disposition of super bulky uran-ore clusters of the Early-Cretaceous age on the territory of South-East Russia (Elkon, Streltsov) and East of Mongolia (Dornod) is predefined with the processes of upwelling of fluid-energetic streams over margin sectors of slab, decayed in transit mantle zone, in other words, with deep-sitting geodynamics. There is an opportunity to use information on spacious position of different elements of slab during choice of potentially prospective areas for geological targeting researches.
Khomich V.G., Boriskina N.G., Santosh M. Geodynamic framework of large unique uranium orebelts in Southeast Russia and East Mongolia // Journal of Asian Earth Sciences, 2016. V. 119. P. 145-166. http://dx.doi.org/10.1016/j.jseaes.2016.01.018
Using joint analysis of the results made with geological, geophysical, seismotomographical research in Eastern Transbaikalia (a decayed oceanic slab was found in transit mantle zone of which) and position of high-yield ore-magmatic systems in Earth’s crust of the region we have specified spacious combination of projection of front part of slab with Dalaynor-Gazimur-Olekma gravity-seismic mineragenetic zone. There are main mass of bulky and super bulky ore clusters and fields containing Au, Mo, U, Pb-Zn, Cu and fluorite mineralization. The conclusion is that cluster-linear position of bulky ore clusters of province is mainly predetermined with deep-sitting geodynamics.
Khomich, V.G., Boriskina, N.G. Advancement of mineragenic regionalization of eastern Transbaikalia based on geophysical studies // Russian Geology and Geophysics. 2017. V. 58. № 7. P. 822-835. https://doi.org/10.1016/j.rgg.2017.06.005