Lithogeochemical patterns associated with the Darrehzar porphyry Cu deposit, Pariz area, Iran

CIM Bulletin, Vol. 90, No. 1014, 1997

H. Ranjbar, Department of Mining Engineering, Shaheed Bahonar University of Kerman, Kerman , I. R. Iran

The Darrehzar porphyry Cu deposit is situated in the Urumieh-Dokhtar magmatic suite of Central Iran. The REE and trace element data suggest that the deposit lies within a continental margin setting. Phyllic and propylitic alteration are pervasive in the area but potassic and argillic alteration are not readily recognized on the surface. This is possibly the result of supergene weathering of the surface rocks or because of an intense phyllic overprint. Poor soil development and abundant outcrop make the area suitable for a case study of lithogeochemical exploration technique for Cu deposits. A total of 262 rock samples was collected over the area and analyzed for 15 elements. The geochemical data correlate with the mineralogical composition of the rocks with the phyllic zone being marked by higher concentrations of Si, Al, K, and by a high sericitization index while Ca, Mg, Sr, total Fe and Mn are more abundant in the propylitic zone. The lithogeochemical study indicates a metal zonation from a Cu + Mo-rich core to a Zn + Pb ± Agrich outer zone. Principal component analysis is useful for separating element associations, which in turn reflect the alteration halos. Principal components 1 and 2 depict alteration zoning, whereas 3 shows an association of Cu and Mo, that roughly defines the mineralized area.

Keywords: Geology, Lithogeochemical patterns, Iran.