Relationship between the Texture and Composition of Titanomagnetite in Hannuoba Alkaline Basalt: A New Geospeedometer

The nucleation and growth of crystals in igneous rocks is usually thought to occur under thermodynamic equilibrium conditions. However, recent studies on textures mineral compositions have shown that these processes probably disequilibrium Titanomagnetite with variable crystal sizes can be observed Hannuoba alkaline basalt, indicating crystallization (different cooling rates). ratio the maximum particle size area abundance titanomagnetite, as determined by an analysis previous texture minerals, was negatively correlated apparent rate. We analyzed chemical composition distribution titanomagnetite ten basalt samples determine connection between rate composition. In samples, found affect cationic substitution solid solution, increase led a decrease Ti4+ Fe3+. partition coefficient Ti melt (DTi) These findings are consistent those experimental petrology help us propose better, more general geospeedometer. also impacted Mg2+ Al3+, but they were crystallinity coexisting melt. Therefore, new geospeedometer calibrated considering composition, content clinopyroxene.The rates measured using this study range from 0.7 7.0 (±0.5) °C/min. It cannot accurately predict intermediate rock, felsic rock or Fe-rich basaltic melts. better measure may identify effects kinetically controlled isotope fractionation, evaluate thermobarometers recognize thermal remanence magnetization ancient magnetic fields.