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Li-F granites all over the world can be represented by three end members, i. e., theNa-rich ongonite (O), the K-rich xianghualingite (X) and the Si-rich topazite (T). Charac-ters and criteria are presented for these end-member rocks. Vertical zoning in Li-F granites, asreflected by increasing normative Q and C (corundum) and decreasing ALK (K2O + Na2O)with increasing content of fluorine, can be explained using the three-end-member scheme interms of petrochemistry and norms. Considering the difference in melt structure, viscosity anddensity between the end members, in couple with the reguarities that govern the Na-K and Si-ALK segregation known from field evidence and experiments, it is suggested that the three endmembers may have resulted from liquid segregation (immiscibility) rather than from crystalfractionation as commonly believed.
Li-F granites all over the world can be represented by three end members, ie, the Na-rich ongonite (O), the K-rich xianghualingite (X) and the Si-rich topazite (T) Vertical zoning in Li-F granites, as reflected by increasing normative Q and C (corundum) and decreasing ALK (K2O + Na2O) with increasing content of fluorine, can be explained using the three-end-member scheme interms of petrochemistry and norms. consideration of the difference in melt structure, viscosity and intensity between the end members, in couple with the reguarities that govern the Na-K and Si-ALK segregation known from field evidence and experiments, it is suggested that the three endmembers may have had adjusted from liquid segregation (immiscibility) rather than from crystalfractionation as generally believed.