Using Models of the Deep Structure of the Earth’s Crust and Upper Mantle Based on GOCE Gravity Data in Metallogenic Analysis

Abstract

Gravimetric data obtained by the GOCE spacecraft contributes to the development of global models of the deep structure of the Earth’s crust and upper mantle (referred to below as global models), improving the understanding of the metallogenic specialization of ore regions. Several examples of using these models in metallogenic analysis are considered here. It is shown that the concept of the global metallogenic homogeneity and zonality of the Pacific Ore Belt (POB) and its boundaries, is well supported by modern maps based on global models. Disputed POB boundaries also receive additional support in the thermal and density model of the upper mantle. Based on the analysis of global models, it is noted that the ore deposits of central and northern Chile clearly gravitate to a region with a denser and colder mantle at depths of 60 km, which corresponds to a flat segment of the subduction zone at the time of ore formation (Miocene), where the dehydration of the submerging oceanic plate and hydration of the upper mantle occurred. The distribution of polymetallic deposits in the Balkans toward the northwest corresponds to the spread of the mean values of density and temperature of the upper mantle. A similar direction is also observed in the structure of the Moho’s surface. Analysis of global models shows that tectonic–magmatic activation during the formation of magmatic arcs due to erosion unearths deposits associated with ophiolites and rifting conditions (Cu–Ni, SEDEX) and the forming of new porphyry Cu, skarn, and/or vein (Pb–Zn) deposits. These results are of great importance in predicting new deposits.