Conditions of crystallization of granites and pegmatites of Tarbaganakhsky massif (Kuluarsky ridge, Verkhoyanye)

Известия высших учебных заведений: Геология и разведка

V. A. Utenkov¹  M. A. Fesenko² 

[1] Российский государственный геологоразведочный университет;ФГУП «ЦНИГРИ»;

关键词: granite;    pegmatite;    deanortization;    adiabatic decompression;    fluid-salt melt;   

DOI  :  10.32454/0016-7762-2015-1-12-21

来源: DOAJ

【 摘 要 】

Compression during granite crystallization in the anticline arch leads to the formation of fluid- gneiss structures and separation of remanent pegmatite melt with its further moving to the periphery of the complex. Two-staged crystalfization is enhanced by presence of Ca in the melt. The early stage is chemical deanortization of plagioclase, the later one - molecular (incongruent) crystallization of K feldspar. The separation of fluid-salt melt (with F, B and water) leads to adiabatic heat of remnant silicate melt and formation of elongated pegmatite veins. The product of the final stage of the grante crystallization and the composition of magmatic base of pegmatite are identical (Q and K feldspar). The primitive composition of magmatic stage of pegmatites (Fe- orthoclase) is in contrast with abundant and aggressive imposing of later minerals during temperature decrease. Mass albitization is the result of Na transfer to the fluid along the incomplete deoxidation of plagioclase. The abundance of muscovite and quartz is paired with Mg outflow in pegmatite tourmatines and chlorite rocks, with Ca and Fe - to the zones of pyroxenization and amfibolization of bearing silts.

【 授权许可】

Unknown