Just when we thought we had analyzed every corner of the earth, our planet reveals yet another secret that leaves us stunned. China recently announced the discovery of a geological treasure so large that it could rewrite global market trends. It is a gigantic gold cave, which, if proven to be real, would change the country’s GDP and the value of an ounce of gold on the market.
This super-giant deposit contains more than 1,000 metric tons of gold, which would be valued—at current prices—at nearly US$83 billion. It seems that China has it all: technological innovation, industrial strength, and now, to top it all off, one of the largest untapped gold deposits on the planet.
The gold cave in Hunan
For now, official authorities have identified and modeled with certainty that there is at least 300 tons of gold within four veins at a depth of 2,000 meters. Thanks to 3D geological models, these rich veins suggest that they slide uninterrupted into the earth to a depth of 3,000 meters. However, the World Gold Council is cautious, as more drilling and much more rigorous audits would be needed to confirm that the 1,000 tons of gold are indeed mineable.
While the World Gold Council (WGC) is asking the press not to get carried away, geologists around the world are intrigued by this discovery. Although the average person may not understand it, the exceptional quality of this cave makes mining this gold very lucrative: the grade of the ore is the concentration of gold in the rock, and spot samples at a depth of 2,000 meters have shown that there are up to 138 grams of gold per ton of rock. For most modern underground mines, it is considered profitable if they obtain between one and 5 grams of gold per ton. This cave is literally and figuratively a gold mine.
The high percentage of gold per ton is so great that it makes the mine viable and profitable despite the costs and risks inherent in mining at such extreme depths. The deposit is located in the Jiangnan Orogen, a tectonic scar formed millions of years ago by the collision of blocks of the Earth’s crust. Hydrothermal fluids—that is, hot water saturated with minerals—flowed through these faults and, as they cooled and changed pressure, precipitated the gold in the 40 veins discovered.
Ultra-Deep Mining
As profitable as this gold mine may be, it poses an immense challenge for mining engineering. Attempting to mine up to 3 km below our soil represents a new technological threshold. Remember that Mount Everest is almost 3,000 m high. Imagine trying to reach that summit… only by digging down. All of this represents a challenge for machinery and human safety.
At such depths, the high pressure of the surrounding rock can cause violent explosions, requiring advanced systems to control and reinforce the tunnel walls. Then there is the high temperature: the natural geothermal heat of the earth at these depths means that the mine requires extensive ventilation and cooling systems to maintain a viable and safe temperature for machinery and workers. Finally, there is the high cost, as creating a groundwater control system and a system capable of hoisting material to the surface is a major engineering feat.
This is why, despite optimistic forecasts, the project is so complex that large-scale extraction would not begin for another 10 to 20 years. Once the mine is operational, annual production is projected to be between 15 and 50 tons. Considering that global gold production is around 3,600 tons per year, the new supply would have a strategic impact, but it would not flood the market and cause the price of gold to collapse immediately.