Short answer: Extreme mines are the ones that hold a record or push against a physical limit: the deepest mine on Earth, more than four kilometres down; a salt mine that tourists ride into by train; a lake that drained into a mine in a single day. This section explains what makes each one extreme, how the record is measured and what it teaches about mining in general.
Most mines are ordinary industrial sites. A few are not. They go deeper, hotter or stranger than anywhere else, or something happened there that has never happened anywhere else. These are the mines people search for, and they are also some of the best ways to understand the limits that every mine works within: heat, pressure, water, rock strength and cost.
Records need definitions
“Deepest”, “largest” and “oldest” sound simple and are not. The deepest mine can mean the deepest working level, the deepest shaft or the lowest point below sea level. The largest can mean annual output, the size of the pit, the amount of rock moved or the size of the reserve. The oldest can mean the oldest still operating or the oldest known evidence of mining.
ResourceClips states the definition behind every record it reports. For depth, we use the deepest active mining level below the local surface. When a record is challenged with better evidence, we review it, and readers can challenge a record directly.
The mines in this section
The deepest mine in the world
Mponeng, a gold mine in South Africa, has workings more than four kilometres below the surface. At that depth the rock is around 60 degrees Celsius and the pressure of the rock above can release violent seismic events. Keeping people alive and working there takes refrigeration, ice and enormous ventilation systems. Read the full story: Deepest Mine in the World: Inside Mponeng’s 4-Kilometre Descent.
The pink salt mine
The Khewra Salt Mine in Pakistan’s Salt Range is the main source of the salt sold worldwide as Himalayan pink salt, although it is not in the Himalayas. It is one of the oldest working salt mines in the world and one of the few mines millions of people have visited. Read more: Pink Salt Mine: Inside Pakistan’s Khewra Salt Mine.
The lake that drained into a mine
In 1980, an oil drilling rig on Lake Peigneur in Louisiana punctured the roof of a salt mine below. The lake drained into the mine within hours, swallowing the rig and a string of barges and reversing the flow of a canal. Every miner escaped. Read more: Lake Peigneur Disaster: The Day a Lake Drained Into a Salt Mine.
What extreme mines teach
Each of these stories points to a constraint that applies to every mine, just more gently:
- Depth multiplies cost. Heat, pressure and travel time grow with every metre. That is why the deepest mines are gold mines: few other metals are valuable enough per tonne to pay for the descent.
- Water changes everything. At Lake Peigneur, water dissolving salt turned a small hole into a total loss. In the desert, the lack of water shapes how mines operate.
- Geology sets the method. Salt mines use room and pillar because salt flows and needs support. Kimberlite, porphyry copper and brine each require their own approach.
- Safety is designed in. At both Mponeng and Lake Peigneur, the decisive factor for the people underground was the system of escape routes, communication and monitoring.
Records change
Mines go deeper, open new pits and close. A record that is accurate today may be overtaken. We date the measurements behind our records and update them when operations change.
Related sections
The largest operations by output are profiled in Major Mines. The economics that decide whether extreme engineering is worth it are covered in Mining & Economics, including what makes a gold mine profitable.
Frequently asked questions
What is the deepest mine in the world?
Mponeng, a gold mine in South Africa, with workings more than four kilometres below the surface.
What is the oldest mine in the world?
Archaeologists have found evidence of mining many thousands of years old, such as ancient ochre and flint mines. Among mines still operating, some salt mines, including Khewra in Pakistan, have very long histories.
What was the strangest mining disaster?
Lake Peigneur in 1980 is often cited: a drilling rig punctured a salt mine beneath a lake, which then drained into the mine in a matter of hours.
Can I visit an extreme mine?
Some are open to visitors. The Khewra Salt Mine in Pakistan is a major tourist attraction, and several historic salt and gold mines around the world offer tours.