“…In this environment, temperatures above 400 C are difficult to maintain because of the cooling effects of irreversible adiabatic expansion ("throttling"), boiling, and mixing with ground water (Toulmin and Clark, 1967;Rose, 1970). There is ample evidence in theory and in fluid inclusions that "moderate" temperature (<400°C) hydro thermal fluids can be expected to introduce or remobilize copper or molybdenum within the host intrusion as well as in intruded host rocks as at Copper Canyon (Nash and Theodore, 1971).…”