Experiment in K/Ar geothermometry and evaluation of thermodynamic parameters in formation of intrusive bodies

Baking of host rocks by a hot dike leads to a decrease in the argon-potassium ratio in biotite and an increase in this ratio in plagioclase. The extent of such redistribution of radiogenic argon and the depths affected by thermal action of the dike accord indications of the temperature of the magma and the duration of its baking action, with a surmise as to the pressure at the time of its crystallization. —IGR Staff