Известия Томского политехнического университета: Инжиниринг георесурсов (Aug 2018)
Geochemistry of tourmaline of greisens and pegmatites of Gorny Altai
Abstract
The relevance of the discussed issue is caused by the need of researching content of tourmaline of greisen and pegmatites of Gorny Altai. Different types of ore mineralization of greisens rare earth pegmatites and jeweler-ornamental stones are related to greisens and pegmatites spatially and genetically. The main aim of the research is to study geochemical features of tourmaline greisens and pegmatites using the experimental diagrams, which allow solving the genetic problems and the physic-chemical features of forming greisens and pegmatites. The methods. Basic elements in tourmaline were defined on wave microprobe JEOL JXA-8100 (Analytic Centre of Institute geology and mineralogy SB RAS (Novosibirck); rare and scattered elements were determined in rocks by inductively coupled plasma method on the mass spectrometer «ОРTIMA-4300», the rest elements, including REE, were determined by La-ISP-MS methods in the Laboratory VSEGEI (Saint-Petersburg) and IMGRE (Moscow). Oxygen isotope composition was defined on the mass-spectrometer MI 1201 V in Institute of geology and mineralogy SB RAS (Novosibirck). Results. The paper introduces the data on geochemistry and petrology of tourmaline from greisenas and pegmatites of Gorny Altai. Aluminous silicate of bore refers to schorl and oxyschorl foitite. Tourmaline of greisens and pegmatites deposits of Gorny Altai have considerable geochemistry distinctions on contents elements-admixtures, acidic-basic of mineral crystallization, character of manifestation of TEF REE M-type. Tourmaline of more evolution, differentiated miarolitic pegmatites differ sharply from schorl of other objects in high concentration of Li, Cu, Zn, Sr, Ba, Ga, Sc, Mn and abundant content of water fluids with such volatile components as F, B, Cl, Li. The highest concentration of W in tourmaline of greisens and Nb in schorl of pegmatites are caused by high acidity of fluid media. Predominant part of tourmaline in the studied deposits does not comply with the charge-radius-control behavior of elements. Tourmaline of greisen and pegmatites with high concentration of tungsten comply with charge-radius-control behavior of elements.
