Graphitized rocks of north part of the Khanka terrane as a new type of complex noble metals deposits

Vestnik Otdelenia nauk o Zemle RAN VOL. 2, NZ11003, doi:10.2205/2010NZ000066, 2010

Graphitized rocks of north part of the Khanka terrane as a new type of complex noble metals deposits

A. I. Khanchuk, L. P. Plyusnina, V. P. Molchanov, E. I. Medvedev

Far East Geological Institute, Vladivostok, Russia

Abstract

The elevated content of noble metals (NM) has been found in the Riphean-Cambrian graphite bearing rocks from the north part of Khanka terrane. The oxidative fluorination and atomic emission spectroscopy were used to analyze wide spectrum of NM: Au- 0.021- 3.57, Ag- 0.2- 4.41, Pt- 0.04- 3.56, Pd- 0.02- 0.55, Ir-0.002- 0.055, Os- 0.011- 0.09, Ru- 0.007- 0.2, Rh- 0.001- 0.74 ppm. Such physical analytical methods as ion mass-spectrometry and neutron- activation performed without preliminary chemical decomposition has verified more high concentration of NM, for example Au up to 17.8, Pt up to 18.55 and Pd up to 6.67 ppm. The distinction reflects an essential loss of volatile metallorganic compositons in result of termoxidative decomposition in process of preliminary chemical sample setting.

Quantum-chemical study of the interaction between Au(0), Pt(0) and Ag(0) and graphene fragments modeling graphite structure defined the more high energy of platinum clusters interaction with graphenes as compared with gold and argentums ones. It may be responsible for the difficulties in detection and analysis of visible Pt phases in graphite. The conclusion was done that generation metallorganic- halogene species realizes in unequilibrium conditions of gas-transporting reactions for which nano-sized forms are predominant. In result inuniform distribution of NM and other metals in graphite takes place. Regional metamorphism and areal graphitization has been conditioned by a magmatic activization. Thus, the studied graphite- bearing rocks can represent the new type of complex NM mineralization different from the black shale formation.

Received 28 October 2010; published 15 November 2010.

Citation: Khanchuk A. I., L. P. Plyusnina, V. P. Molchanov, E. I. Medvedev (2010), Graphitized rocks of north part of the Khanka terrane as a new type of complex noble metals deposits, Vestn. Otd. nauk Zemle, 2, NZ11003, doi:10.2205/2010NZ000066.