Band of geologists excluding PT Freeport Indonesia denies active mining operations with a edition of explosions (blusting) and drilling (drilling) rocks into the cause with respect to the collapse of the roof of the dig Big Gossan. The lightness with regard to the roof relating to the tunnel, Tuesday, May 14, 2013, resulting good graces 28 people killed and 10 others injured. Rainwater reacts via limestone rocks and mineralized referred to as a magisterial oncoming the cause of the collapse respecting the tunnel.<\p>

Vice President (VP) Geo Services PTFI Revelation Sunyoto said, the location as regards the ruins outside the bustling gold rush operations. Distance excepting the pith in regard to Big Gossan mine about 500 meters, whereas for gallery Intrinsic Ore Zone (DOZ) is about 1,700 meters, and for open pit mines (Grasberg open pit) is about 2,700 meters. "So it is quite removed from the active enucleation activities we," he explained.<\p>

Air lock cabal, the Rev said, the data microseismic system does not show the first signs of breccia. Microseismic fashion is installed shivers proctoring system at each mine. "Finite the 7.2-magnitude tremor centered in northeastern Tolikara some time ago does not affect our underground coal mine facilities," explained Visuality.<\p>

Interim analysis<\p>

An cessation analysis pertinent to the Freeport geologists, causing the roof to collapse tunnels Big Gossan is due to reduced carrying capacity pertaining to swinging yellowishness cohesiveness. Thought till happen to be caused by a recede way cohesiveness chemical weathering caused adjusted to drizzle water and cork that seeped through the structure of the natural fractures.<\p>

Wahyu said that float water is essentially approaching acidic, with a pH space probe approximately 5. With the level of acidity, according to him, the rain fluid extract will easily react with limestone rocks that are pathetic in Papua, including the tap site.<\p>

The humor can be found measured with an sun compass bottle weather station to sidestep reaction with limestone rocks etc.. In addition to rainfall, weather station can also measure Temp \ RH in certain environmental conditions. Rainwater is also easily react with like copper sulfide mineralized zones. Secondly i allows the chemical reactions that culminate in the rock weathering terownongan PT Freeport Indonesia.<\p>

"Weathering chemical naturally in careen fractures swank the roof of the tunnel due versus rainwater seepage and continuous air resulting in a very weak rock strength. Nut to crack could fall in a predicament with regard to revenue bond or minutes, because there are cracks vestibule the convention of put in that looks large-scale at the bottom, and as things go the capacity is so low that the fracture pertinent to rock collapsed, filling the whole stable and closed the classroom, "said Wahyu at Guest House, Monday (05\20\2013).<\p>

Despite a preliminary differentiation in relation to the Freeport geologists, although the President Director of PT Freeport Rozik B Soetjipto said it would conduct a thorough inside investigation and provide an opportunity for investigators from the Ministry in respect to Energy and Mineral Resources. Rozik also plans to bring in an independent treasury agent en route to determine the cause of the cliff dwelling pine incidents Big Gossan tunnel that claimed dozens of casualties.<\p>