The Kukaazi Pb-Zn deposit was recently discovered in the western Kunlun orogen (WKO), NW China. This deposit consists of three ore blocks (ICI to KIII) hosted in Mesoproterozoic metamorphosed rocks. Ores are mainly composed of sphalerite, galena, chalcopyrite and scheelite. Here we present in-situ LA-ICP-MS trace elemental compositions of sphalerite and galena of sulfide ores from ore blocks KI and MI, to shed light on the ore formation and its regional tectono-metallogenic implications. Sphalerite from ore block KI contains higher contents of Fe, Mn, Co, Cu, Bi, Sn, and Sb than sphalerite from ore block KU. Nonetheless, sphalerite from the two ore blocks has compositions similar to the sphalerite from typical skarn deposits. Galena from ore block KI is compositionally different from galena from ore block MI, and has relatively high Ag, Cd and T1 contents and low Sb content. Such differences are probably due to different ore-forming temperatures in these two ore blocks. Based on the Cd partition coefficient between the co-existing sphalerite-galena pairs, sulfide ores in ore block KI may have formed under higher temperatures (265-387 degrees C) than those in ore block MI (229-251 degrees C).

Combined with previous studies, we propose that the Pb-Zn mineralization at Kukaazi was distal skarn related and formed in a continental arc setting. Discovery of this deposit implies that WKO is a promising area for future porphyry/skam-related Pb-Zn (-Cu-W) mineral exploration in northwestern China.