Hi John, agreed - if you are referring to high-T fluid inclusion studies in quartz. However in combination with mineral equilibria, fluid inclusions in other peak metamorphic minerals such as garnet or sillimanite are an important tool to constrain the peak metamorphic fluid chemistry and give insight in fluid-rock interaction during peak conditions. Maybe its the only straightforward way .... Cheers, Reiner > ****************************** Reiner Klemd Professor fuer Geochemie und Lagerstaettenkunde Institut fuer Mineralogie Universitaet Wuerzburg Am Hubland 97074 Wuerzburg Tel.: 0931/8885412 Fax.: 0931/8884620 **************************************