Mass Change Calculation of Elements in the Khut Cu Deposit, West of Yazd

Khut Copper deposit, located in west of Yazd, is one of the most important skarn deposits in Taft mining area that situated in the middle part of the Urumieh-Dokhtar magmatic belt. Intrusion of Khut granodioritic stock into carbonate component of the Nayband Formation has led to the formation of Cu skarn deposit and different skarn zones. Mass changes has led to mineralogical changes in the different skarn zones. In this paper, element mass changes and element mobility in the skarn zones relative to the unaltered carbonates rocks are calculated. Results of these calculations show the most mass increase in the major elements of Si, Fe and Mn in the skarn zones. REE and the other rare elements such as Rb, U, V, Nb,Cr, Y, Cu and Zn have also shown mass increase. Enrichment value in the light rare earth elements can be attributed to the abundance of garnets and its composition, so that the amounts of light rare earth elements in the Al bearing garnets are higher than andradite garnets. In this paper, the causes of these changes and their effects are discussed by using geochemical method of mass change calculations.