Textural evolution of synthetic fluid inclusions in quartz during reequilibration, with applications to tectonic reconstruction

Abstract

Experimental reequilibration of synthetic 10 wt% NaCl-H2O inclusions in natural quartz reveals that reequilibration textures show distinct differences depending upon the P-T path followed by the inclusion after formation. These differences combined with other geological information may be used to determine whether the sample (rock) followed a dominantly isothermal or isobaricP-T path following entrapment. The intensity and style of inclusion reequilibration features is related to the direction and magnitude of the departure of theP-T path from the original isochore for the inclusion. Thus, fluid inclusion reequilibration textures not only permit inclusionists to determine whether the rocks followed an isothermal or isobaric retrogradeP-T path, but also the magnitude of departure of this path from one that is isochoric.