锂氟花岗质岩石三端元组分的发现及其液态分离成因

从世界范围研究锂氟花岗质岩石发现有三端元组分,即富Na的翁岗岩(O)、富K的香花岭岩(X)和富Si的黄英岩(T)三端元,提出区分三端元的三角图和划分标志。该类岩体垂直分带表现出三端元O→X→T变化规律,反映在化学成分和标准矿物上,有随F含量增加,Q、C(刚玉)升高,ALK(K_2O+Na_2O)降低的趋势。根据三端元的熔体结构、粘度、密度差异和Na-K、Si-ALK分离规律,结合实验资料,认为三端元是不混溶为主的液态分离成因,与传统的分离结晶作用不同。

DISCOVERY ON THE THREE END-MEMBERS' COMPONENTS OF Li-F GRANITE ROCK AND ITS LIQUID-STATE SEPARATION ORIGIN

It has been discovered that Li -F granite rock in the world has three end-members which are Na-rich ongonite(O), K -rich Xianghualing rock(X)and Si-rich topazite(T). Correspondingly,Triangular diagram and determination markers are proposed. The vertical zoning of this kind of rock body presents such a trend that changes from O through X tp T in the three - members,which shows,by their chemical compositions and standard minerals,O and C(corundum) increase and ALK(K2O +Na_(2)O) decreases with the increment of F content. According to the structure,viscosity,density difference of the melt of the three - members and the fractional laws of Na -K and Si -ALK,and combined with experimental data,it is proposed that the three-members are originated from immiscible dominated liquid -state separation,which is different from the traditional fractional crystallization.