Petrogenesis of High-Ti and Low-Ti Basalts from the Emeishan Large Igneous Province

Analyses of basalts from the Emeishan large igneous province show that the TiO 2 contents of them are variable continuously. And outcrops of high Ti and low Ti basalts in field are unzoned spatiotemporally. The similar Sr, Nd and Pb isotopic compositions of these two types of basalts indicate that they are comagmatic igneous rocks. The MgO versus TiO 2 diagram for picrites and basalts shows four evolution trends, whose geneses were simulated by the fractional crystallization model. The result suggests that high Ti and low Ti basalts are different products of the same parent magma (picritic basaltic magma) through fractional crystallization of different minerals.