We’ve been digging since the dawn of time – turning earth in search of water, metals, minerals and gems. Caves, tunnels, crypts, bunkers, treasure vaults, food storage – purposely hewn testaments to our ingenuity.
Bingham Canyon Copper Mine in Utah is the largest man made hole on the planet. Three quarters of a mile deep, two and a half miles wide, In continuous production since 1906 – now owned by United Kingdom based Rio Tinto – it dodged falling copper prices and a planned closure in 2013, when copper prices began to climb. Rio Tinto has plans to build a second mine, 2000 feet beneath the floor of the existing open pit.
Second place goes to the Mirny Diamond Mine in Siberia -1,722 feet deep and 3,900 feet wide – between 1955 and 2001, it produced over 10 million carats of diamonds every year. Large scale mining has ceased in the open pit, mining activity now takes place underground.
Kimberly Mine in South Africa deserves mention for reaching a depth of 705 feet, width 3,600 feet – dug entirely by hand. Between 1871 and 1914. upwards of 50,000 men armed with picks and shovels, extracted 6000 pounds of diamonds from this ridiculously steep round hole.
The Kola Borehole in Russia is in a league of its own. Who knew Russia and America not only raced for space – each wanted to be the first to reach Earth’s core. American effort “Project Mohole” exhausted funding in 1966, the site off the coast of Mexico in the Pacific Ocean was abandoned. Starting in 1970 until 1994, Russian scientists managed to bore a hole 7.5 miles into Earth’s crust. The project closed when temperatures at the business end exceeded 356 degrees Fahrenheit – super heated rock behaved more like plastic, making further drilling impossible. Far from being deemed a failure – core samples showed the existence of biological fossils in rock more than 2 billion years old. In all, 24 species of single cell marine plankton were identified.
Far from being the whole story – tomorrow I’ll look at ancient holes.