Nulasai Cu deposit, Nileke Co. (Nilka Co.; Nilqa Co.), Yili Hasake Autonomous Prefecture, Xinjiang, Chinai

Regional Level Types
Nulasai Cu deposit	Deposit
Nileke Co. (Nilka Co.; Nilqa Co.)	County
Yili Hasake Autonomous Prefecture	Prefecture
Xinjiang	Autonomous Region
China	Country

Middle-low temperature hydrothermal copper deposit.

There is an ancient mine in the deposit area. The Nulasai deposit is the earliest Cu mine in Xinjiang, NW China, and has been mined and smelted since the warring state period.

Nulasai deposit region is mainly covered by Permian volcano-sedimentary succession, including the Lower Permian Wulang Formation (P1w), the Middle Permian Xiaoshansayi Formation (P2x), and the Quaternary sediments. The faults mainly cut the Middle Permian Xiaoshansayi Formation and granite porphyry, and associated fracture zones and breccias are well-developed. The tectonic fracture zones are about 10–30 cm in width and consists primarily of granite porphyry fragments and rock powders; the fault breccias are angular and partially cemented by late calcite veins. Distribution of orebodies are controlled by fault structure zone between the two major faults.

Two main ore zones were identified by geological surveying: the south and the north. There is one recognized Cu orebody in the south ore zone. Three defined Cu orebodies in the north ore zone. These orebodies are situated subparallel to the F1 and F2 fault, which trend northwest. The No. Ⅰ, Ⅱ, Ⅲ Cu orebodies in the north ore zone are coexistence with Pb and Zn mineralization, and the No. Ⅳ orebody in the south ore zone coexistence with Ag orebodies. Cu orebodies are mostly found in granitic porphyry and tuffaceous sandstone as veins and lenticular bodies. As a typical example, the No. Ⅱ-1 orebody looks to be vein type, and compose of calcite-barite-bornite-chalcocite-chalcopyrite veins, and Calcite-barite-sphalerite-galena-chalcopyrite veins. The orebody is inclined downwards (60°–82° S), extends up to 500 m, and the thickest part reaches 12 m, with an overall east–west distribution. Average ore grades are 2.3 % Cu, with additional Pb (3.65 %) and Zn (7.96 %) mineralization.
The stage I is concentrically distributed in the quartz diorite porphyry, comprising mainly of magnetite–quartz–chalcopyrite ± bornite ± K-feldspar ± plagioclase veins, and is associated with local potassic alteration. The stage II represents the main hydrothermal stage at the Nulasai, and is mainly developed in the shallow depths compared to stage I. The stage III is characterized by the presence of significant copper and minor lead and zinc mineralization.

Other Regions, Features and Areas containing this locality

References