Pulang Cu deposit (Xuejiping Cu deposit), Shangri-La County, Dêqên Autonomous Prefecture, Yunnan, Chinai

Regional Level Types
Pulang Cu deposit (Xuejiping Cu deposit)	Deposit
Shangri-La County	County
Dêqên Autonomous Prefecture	Prefecture
Yunnan	Province
China	Country

Porphyry copper deposit, hosted in quartz monzonite and monzonitic granite intrusions. Skarns are developed along the contact zone with overlying Triassic limestones. The ore district mainly consists of the Late Triassic Tumugou Formation and large-scale porphyry intrusions over an area of 8.9 km²

The primary exposed strata in the Pulang mining area are the Upper Triassic Tumgou Formation (T3t) and a small number of Quaternary strata. The Tumgou Formation can be divided into two components. The first (T3t) is distributed in the western section of the F1 fault in the mining area, with an NW trend. The overall trend is northwest, dipping towards SW, with an inclination of 68°~82°. The lithology is gray to dark gray slate, sericite slate, and metamorphic sandstone, with thin layers of limestone locally mixed. The rocks close to the rock bodies are hornfels, formed by thermal metamorphism, with a total thickness of more than 400 meters. The second component of the Tumgou Formation (T3t) is located on the southwest and eastern side of the mining area and is in conformable contact with the underlying of T3t. The lithology is gray to dark gray slate, silty sericite slate, mixed with metamorphosed sandstone, andesite, etc., with a total thickness of >1000 m. The Quaternary stratum in the area consists mainly of glacial sediments with complex components, including fragments of varying sizes of metasandstone, slate, quartz monzonite porphyry, quartz diorite porphyry, and granite diorite porphyry, with a thickness of 0–74.96 m.
The Pulang porphyry complex consists of quartz diorite porphyries (oldest), quartz monzonite porphyries, and diorite porphyry (youngest) emplaced during the Indonesian period. Mineralization and alteration occur together, both consisting of veinlet-disseminated ores at the center of the intrusion. Veined ore bodies occur on the edge of the rock body and in their host rocks. The classic porphyry-style alteration zonation pattern proposed does not apply to Pulang, in which epidote–chlorite alteration extends from the deposit core outward and has a strongly overprinted early potassic alteration. The unusual pattern observed at Pulang may be attributed to fluids from a nearby porphyry deposit that overprinted an epidote–chlorite
alteration onto a pre-existing copper mineralization and potassic alteration at Pulang. Alternatively, it could be the result of the collapse of epidote–chlorite stable fluids into the potassic-altered core during the waning hydrothermal activity.
The KT1 ore body in the first mining area is composed of quartz diorite porphyries, quartz monzonite porphyries, and granodiorite porphyries and occurs in the form of stocks, with an outcrop area of 6.53 km2. This orebody is in the form of a large lens. It lies along a NW trend, with a N–S length of 1760 m and widths of 500–620 m, 170–490 m, and 560–700 m, respectively, in their northern, central, and southern parts. The alteration types of this orebody mainly include potassic alteration and silicic alteration, followed by sericite alteration and albite alteration, with clay, chlorite, and saussurite alterations occurring locally. Sulfides broadly occur in the former two zones, and the surrounding rocks in the outer contact zone feature hornfelization and irregularly dispersed pyrite (pyritization).
The orebody KT1 controls 1425.89 million tons of ores and 4.82 million tons of metals, with an average grade of 0.34%. A total of 15 large-veined copper ore bodies have been delineated in the eastern ore section of the deposit, mainly occurring in quartz diorite porphyries at the edge of the intrusion, with a few of them extending into the hornfels. The KT4, KT5, KT6, and KT19 orebodies are relatively large in size and are controlled by a series of near-EW trending joint–fault structures.
At present, this deposit has been established to host Cu resources of ~5 × 106 t (with an average grade of 0.52%), Mo resources of ~1.7 × 105 t (with an average grade of 0.01%), and Au resources of 145 t (with an average grade of 0.18 g/t), along with 1459 t of Ag and 0.4 × 106 t of Pb + Zn. According to the distribution of ore bodies, the deposit can be further divided into the South, East, and North Ore Sections.

Localities in this Region

Other Regions, Features and Areas containing this locality

References