Phlogopite-olivine rocks of the Taukha terrane in southeastern Sikhote Alin

The Paleocene ultraferrous Mn-rich phlogopite-olivine rocks of the Taukha terrane belong to the alkaline ultrabasic rocks of the potassic series. The olivine is represented by hortonolite, while the phlogopite is enriched in Cl. Other minerals are represented by Ti-magnetite, Mn-rich ilmenite, Zn-rich pleonaste, apatite, and zircon. There are also epigenetic serpentine, talc, carbonates, magnetite, breithauptite, nickeline, hedleyite, cobaltite, tsumoite, auricupride, cuproauride, and other minerals. The phlogopite-olivine rocks possibly represent a part of a magmatic complex previously unknown in Sikhote Alin, the rocks of which are associated with fluidolites of a large diatreme. There are grounds to suggest that they were formed by the injection of fluid-rich (mainly, H₂O, Cl, F, and S) deep magmas into the upper lithosphere. Based on these specific features, as well as the sharp K predominance over Na and the enrichment in some incompatible elements (Sn, Ta, Nb, and Zr), the phlogopite-olivine rocks are the most close to lamproites but differ in the high contents of Fe, Mn, Au, Pt, and Pd and in the olivine’s composition. The manifestation of such magmatism in the Taukha terrane records the transition from subduction to transform continental margin settings.