EVALUATION OF THERMOMETRY CAPACITY OF CLAY MINERALS: EXAMPLE OF THE GULF COAST'S CHLORITES (TEXAS)

摘要

These 25 last years, several thermometers based on chlorites' chemistry were gauged. In fact, two methods were explored: the empirical calibration and the thermodynamic calculation of equilibrium conditions. In the first case, Cathelineau (1988) showed the direct correlation between tetrahedral Al occupancy and measured temperatures. This empirical calibration was then corrected with the XFe (XFe = Fe/(Fe+Mg) ) parameter by several authors, with the aim of extending their applicability. These thermometers can be easily calculated, but do not take into account the effects of the bulk-rock composition. On the contrary, the second method includes the effects of rock mineralogy's variations.