Thermobaric granite crystallization conditions of the severniy massif (the Chukotka) in accordance with the feldspars study data
- канд. геол.-минерал. наук Assistant Professor Saint-Petersburg State Mining Institute (Technical University)
Abstract
The Kamentsev I.E. and Sorokin N.D. method is used to investigate the dependence of Al-Si-ordering and structure of alkaline feldspars decomposition in different granites from the Severny massif (Chukotka) under thermobaric conditions of their crystallization. The temperature and pressure on the granite system in the initial period of feldspars ordering are determined quantitatively for the first time for the region. Progressive pressure change which exceeds lithostatic load by 750 МPа at the late stage of lithium-fluoride granites formation is revealed. It is hypothesized that the deposits similar to explosive ore-bearing breccia can be discovered in the Chukotka. The conclusion on possibility to apply the Sobolev-Dobretsov concept of superpressure to interpret the process of rare-metal magmatism is drawn.
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