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The East Pana intrusion is a part of the Paleoproterozoic Fedorova–Pana complex (FPC), which belongs to the group of Fennoscandian layered mafic–ultramafic massifs. This article discusses the magmatic stratification of the East Pana intrusion, as well as Cu-Ni and platinum-group elements (PGE) mineralization (PGE zones A, B and C) in its various parts with a total length of more than 20 km, including the East Chuarvy PGE deposit. Based on the whole-rock data on the distribution of major, trace, and ore-forming elements, it is assumed that PGE zone A belongs to the main ore–magmatic system of the FPC, while PGE zones B and C belong to the minor ore–magmatic systems. At the same time, additional magmatic injection played an important role in the formation of economic Cu-Ni-PGE mineralization (PGE zone B), characterized by high PGE concentrations and moderate palladium enrichment. On the normalized distribution spectra of trace elements, the crystallization products of this injection (Gabbronorite Zone 2) have a positive Zr-Hf anomaly, which distinguishes it from host rocks with an anomaly of the opposite sign (Gabbronorite Zone 1, Gabbro Zone). It is assumed that this portion of magma was intruded as a sill of crystal mush, the fractionation of which at depth led to its enrichment with residual liquid. [ABSTRACT FROM AUTHOR]

The South Sopchinsky massif (SSM), Gabbro-10 (G-10) massif, and Moroshkovoe Lake (ML) target Monchegorsk area, Kola Peninsula, are located at the junction of the Monchepluton and Monchetundra layered intrusions. The intrusions were studied in detail as they are targets for platinum-group element (PGE) mineralization. The rocks in these targets comprise medium- to coarse-grained mesocratic to leucocratic gabbronorites, medium-grained mesocratic to melanocratic norites and pyroxenites, and various veins mainly comprising norite, plagioclase-amphibole-magnetite rocks, and quartz-magnetite rocks. The veins contain Ni-Cu-PGE mineralization associated with magnetite and chromite. In all targets, the contacts between gabbronorite and norite-pyroxenite are undulating, and the presence of magmatic (intrusive) breccias suggests that these rocks formed through mingling of two distinct magmatic pulses. In places, the gabbronorites clearly crosscut the modal layering of the norites and pyroxenites. Trace element data indicate that the gabbronorites have similar compositions to rocks of the upper part of the Monchetundra intrusion, whereas the norites and pyroxenites resemble rocks from the lower to intermediate stratigraphic levels of the Monchepluton, such as in the Nude-Poaz and Sopcha massifs. Sulfide mineralization in the studied targets principally consists of secondary bornite, millerite, and chalcopyrite. In contrast, the primary sulfide assemblage within the layered sequence of the adjacent Monchepluton is characterized by pentlandite, chalcopyrite, and pyrrhotite. Therefore, the mineralization in the studied targets is interpreted to be of a contact style. We argue that the studied area represents the contact zone between gabbronorites of the Monchetundra intrusion and norites and pyroxenites of the Monchepluton. In addition, the rocks were overprinted by postmagmatic veining and remobilization of contact style sulfide and PGE mineralization. [ABSTRACT FROM AUTHOR]