Geophysical research: article

NEURAL NETWORK CLUSTER ANALYSIS OF AREAL GEOPHYSICAL DATA OF THE KHIBINY-LOVOZERO VOLCANO-PLUTONIC ORE-BEARING COMPLEX (KOLA PENINSULA) BY SELF-ORGANIZING MAPS OF KOHONEN METHOD
I.I. NIKULIN1
A.A. SAMSONOV2
1 Norilskgeologiya LLC
2 Lomonosov Moscow State University
Journal: Geophysical research
Tome: 22
Number: 1
Year: 2021
Pages: 25-39
UDK: 004.891.3; 550.8.053
DOI: 10.21455/gr2021.1-2
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Keywords: gravity exploration, magnetic exploration, hierarchical model, artificial neural network, Kohonen map, fuzzy logic, cluster analysis
Аnnotation: The method of automatic express-interpretation of areal geophysical data is described using the example of the Khibiny-Lovozero volcano-plutonic complex. Within the framework of this method a complex geophysical-mathematical model was built, consisting of fifteen levels of hierarchy and based on the use of the mathematical apparatus of artificial neural networks. The method of self-organizing Kohonen maps was used in the processing of geophysical survey data. This is a mathematical apparatus of fuzzy logic, which artificial neural network is trained without a teacher. The formation of groups of clusters that characterize to the fullest extent the possible connections between multidimensional geophysical data is substantiated. As well as the presence of relationships between them is analyzed by identifying correlation dependences. The analysis of various geophysical transformants using self-organizing Kohonen maps is carried out. The clusters that as a result of the study reflect the picture of a major Paleozoic ore-magmatic system in the northeast of the Fennoscandian Shield were calculated using an artificial neural network. This system brings together the Khibiny and Lovozero plutons, Kurginskaya intrusion, volcanic formations and numerous swarms of alkaline dikes. A number of input indicators-representatives of their groups were determined and, on their basis, a geophysical-mathematical model in the form of a two-dimensional map of clusters using fuzzy logic tools was built. Terminological sets for each group of clusters were formed, the form of membership functions of previously unknown geological objects was specified according to the new interpreted data and their parameters in relation to the main ring of the Khibiny array, that controls rare-earth-titanium-aluminum-phosphorus deposits, and Fedoro-Panskaya Tundras (platinum-paladium deposits). Potential objects for geological exploration near the Lovozero eudialyte zircon rare-earth deposit are proposed. The conducted experimental study confirmed the adequacy of the constructed model and the effectiveness of its use for the purpose of express analysis of geophysical data and decision-making in geological prospecting tasks.