The Grasberg minerals district is situated on the crest of the Sudirman Mountain Range at elevations over 2,500 meters with the highest peak, Puncak Jaya at 4,884 meters. Ore deposits in the Grasberg minerals district have economic copper, gold, and silver mineralization in porphyries and skarns. The primary sulfide mineralization is chalcopyrite, with lesser bornite, chalcocite, and covellite. Gold concentrations usually occur as inclusions within the copper sulfide minerals although in some parts of deposits gold can also be strongly associated with pyrite.

There are five major ore bodies all within the center of the Grasberg minerals district:
• Grasberg Intrusive Complex (GIC) includes the GBC and the depleted GRS_OP.
• EESS includes DMLZ and depleted GBT, IOZ, DOZ block caves.
• BG.
• KL (development stage mineral reserve).
• Dom (classified as mineral resource).

In Grasberg Block Cave (GBC) Mine area, anhydrite-gypsum and sulfur mineral distribution can be traced in Grasberg Intrusive Complex (GIC), skarn, and Heavy Sulphide Zone (HSZ).

GIC and Skarn contain abundant of anhydritegypsum as product of alteration. Potassic alteration in GIC are characterized by anhydrite appearance within the rock or as intense stockwork veins associate with quartz-pyritechalcopyrite. In the skarn, anhydrite mineral appear as dominant alteration mineral especially if the skarn occurred between contact of igneous rock and Warip ........

The Grasberg Block Cave ore body is the same ore body historically mined from the surface in the Grasberg open pit. Undercutting, drawbell construction and ore extraction activities in the Grasberg Block Cave underground mine continue to track expectations. Monitoring data on cave propagation in the Grasberg Block Cave underground mine is providing confidence in growing production rates over time. As existing drawpoints mature and additional drawpoints are added, cave expansion is expected to accelerate production rates to an average 116,000 metric tons of ore per day in 2023 and 130,000 metric tons of ore per day in 2024 from five production blocks spanning 335,000 square meters. As of December 31, 2022, the Grasberg Block Cave underground mine had 386 open drawbells.

The Grasberg Block Cave fleet consists of approximately 580 pieces of mobile equipment. The primary mining equipment directly associated with production and development includes an available fleet of 97 LHD units and 26 haul trucks. Each production LHD unit typically carries approximately 11 metric tons of ore and transfers ore into the rail haulage system. The Grasberg Block Cave has a rail haulage system currently operating with 10 locomotives and 120 ore wagons that haul the ore to the first 2 of the 3 planned gyratory crushers located underground via an automated rail system. Each ore wagon typically carries 35 metric tons. The crushed ore is conveyed to surface stockpiles for processing.

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