Leading the Way

Deposit types

Deposits and occurrences in the area include: 1) porphyries, 2) skarns, 3) veins in fracture zones; and 4) ice accretion type. The first two deposit types are found on the contact zones of the porphyritic, Yanshanian, biotite granite stock. The most important deposits are the skarns and veins in fracture zones. The most important metals are silver, tin, lead, zinc, and copper. Characteristics of mineral occurrences in the district are summarized in the Table given below.

Genetic Type Deposit Type Summary of Character Examples
Skarn Tin-Polymetallic Produced in mineralized skarn as stratoid, lentoid and vein structures (Sn, Pb, Zn, Cu and Au). Hailong and Cuomolong
Copper Skarns external to intrusive. Small scale and low grade. Wanlongba, Yurong, and Bannan
Hydrothermal Tin-Polymetallic Altered granites with cassiderite veins and cassiderite sulphides. Relong and Jiaogenma
Copper Occurs in a felsic hornfels containing pyrite and chalcopyrite with 0.03% to 0.8% Cu. Yuqieke and Konglongluo
Lead-Zinc Produced in Upper Triassic sandstone in veins. Very small scale. Sende
Iron Magnetite in Upper Triassic slate and hornfels. Fe values range from 17.6% to 58%. Dedadong
Tungsten-Tin In contact zone of Cuopu granodiorite intrusion. Mineralization in hydrothermal veins ranges from 0.34% to 2.25% W and 0.02% Sn. Lianlong South Branch
Silver-Poly NW structure, statiform, podiform to lenses and veins. Xiasai, Duoluoquingguo and Relangze.
Porphyry Molybdenum Altered granite of Rongyicou Mass contact. Mineralization in veins, 0.11% Mo and 0.34% Be. Cuopugao Lake

The 1:200,000 scale, silt survey for Yidun showed anomalies for tin(Sn), tungsten(W), bismuth(Bi), silver(Ag), lead(Pb), zinc(Zn), copper(Cu), cerium(Ce), arsenic(As), gold(Au) and mercury(Hg). The composite anomaly area covers 126 km2 in the Xiasai area. The area has a high of 8.0 ppm Sn compared with a background for Sichuan of 3.9 ppm Sn. From east to west the most abundant metals are gold, mercury, polymetal-copper, polymetal-tin, tungsten and polymetal. Mineral occurrences are related to the bitotite-monzonite porphyries of the Genie-Changduokuo Zone. Small and medium sized tin deposits in the region include: Gongjuelong, Chqiong, Xingpule and Chaihuogou. Silver-lead-tin deposits include Xiasai, Shaxi and Jiaogenma. The northwestern section of the intrusion contains tin-polymetal deposits such as Cuomolong, Hailong, Relong, and Lianlong.