Литосфера (Oct 2017)
The first finding of rodingites with a gold-palladium-platinum mineralization within the Sikhote-Alin
Abstract
The subject of investigations were rodingites, whose outcrops were recently found inTaukha terrane of the Sikhote-Alin. The contents of the rock-forming oxides in rodingites were determined using the methods of chemical analysis as well as the gravimetry (SiO2, H2O, and Loi) and atomic-emission spectrometry with the induction-bound plasma at the iCAP 6500Duo spectrometer (Thermo Scientific Corporation, USA) (other oxides). The contents of the secondary elements were determined with the method of mass-spectrometry with the induction-bound plasma at the Agielent 7500 с spectrometer (Agielent Technologies, USA). Analyses of minerals were done using the JXA8100 microanalyser with three wave spectrometers and the INCAx-sight power-dispersion spectrometer. The contents of precious metals were determined with the atomic-absorption method. The paper presents the results of investigations of the geological conditions of occurrence, petrochemistry, geochemistry, and mineralogy of rodingites and the Au-Pd-Pt mineralization in them. The rock-forming minerals of rodingites of the Sikhote-Alin’ are pyroxene, garnet, vesuvian, epidote, prehnite, amphibole, chlorite, plagioclase, potassium-feldspar, apatite, zircon, titanite, and others. In rodingites of the Sikhote-Alin’ there were found the relatively high contents of Au, Ag, Pt, and Pd and the typical of such rocks “copper gold” and native forms and intermetallic compounds of diverse metals. The investigations carried out allowed the substantiation of the conclusion about the genetic relation of rodingites with the Paleocene ultrabasic-intermediate and alkaline-subalkaline complex of the Sikhote-Alin’. The rodingites were formed by metasomatic way on the basic and ultrabasic rocks of the vent and intrusive phases. They have preserved some geochemical characteristics of protoliths, in which they clearly differ from skarns with the boron, polymetal, and iron mineralization of the Dalnegorsky and Olginsky ore districts and from the contact-metamorphosed Triassic metal-bearing sediments of the Sikhote-Alin’. The Paleocene magmatic complex of the Sikhote-Alin’ is of a special interest because with it the precious-metal mineralization is genetically related that is localized not only in rodingites but also in other rocks of the Paleocene explosive structures and in the alluvium of the springs draining them.
