Monticello Dam was constructed between 1953 and 1957. The dam is a medium concrete-arch dam with a structural height of 304 ft (93 m) and a crest length of 1023 ft (312 m). It contains 326,000 cubic yards (249,000 m?) of concrete. Napa County, California, United States.
Guatemala city - A 330-foot-deep sinkhole killed at least two teenagers as it swallowed about a dozen homes early Friday and forced the evacuation of nearly 1,000 people in a crowded Guatemala City neighborhood. Officials blamed the sinkhole on recent rains and an underground sewage flow from a ruptured main.
Mir Mine (kimberlite diamond pipe “Peace”) is an abandoned open pit diamond mine located in Mirny, Eastern Siberia. The mine is 525 m deep and has a diameter of 1200 m. It was the first and one of the largest diamond pipes of the USSR.
The Bingham Canyon Mine is an open-pit mine extracting a large porphyry copper deposit southwest of Salt Lake City, Utah, USA, in the Oquirrh Mountains. It is owned by Rio Tinto plc through Kennecott Utah Copper Corporation which operates the mine, a concentrator and a smelter. The mine has been in production since 1906, and has resulted in the creation of a pit over 0.75 miles (1.2 km) deep, 2.5 miles (4 km) wide, and covering 1,900 acres (7.7 km2). According to Kennecott, it is the world’s largest man-made excavation.
Over its life, Bingham Canyon has proven to be one of the world’s most productive mines. As of 2004, ore from the mine has yielded more than 17 million tons (15.4 Mt) of copper, 23 million ounces (652 t) of gold, 190 million ounces (5386 t) of silver, and 850 million pounds (386 kt) of molybdenum. The value of these resources is greater than the Comstock Lode, Klondike, and California gold rush mining regions combined. Cumulatively, Bingham Canyon has produced more copper than any other mine in the world, although mines in Chile, Arizona, and New Mexico now exceed Bingham Canyon’s annual production rate. High molybdenum prices in 2005 made the molybdenum produced at Bingham Canyon in that year worth even more than the copper. The value of the metal produced in 2006 at Bingham Canyon was US$1.8 billion dollars.
The mine is regarded as one of the most up-to-date integrated copper operations in the world, employing 1,400 people. The smelting and refining facilities are recognised as being among the world’s best for environmental protection practice and achievement.
The infrastructure required for an operation this size is impressive. 450,000 tons (408 kt) of material are removed from the mine daily. Electric shovels can carry up to 56 cubic yards (43 m3) or 98 tons (89 t) of ore in a single scoop. Ore is loaded into a fleet of 64 very large dump trucks which each carry 255 tons (231 t) of ore at a time, at a cost of approximately US$3 million per truck. There is a five mile (8 km) series of conveyors that take ore to the Copperton concentrator and flotation plant. The longest conveyor is 2.5 miles (4 km) long and passes through an existing railroad tunnel inside the mine.
Kimberley is famous for the Big Hole, which is often called the worlds deepest man made hole. Kimberley is the place where diamonds are found. And the Big Hole is a huge pit, almost circular and 215m deep, right in the middle of the town. Just for completeness sake: Kimberley Big Hole is not the biggest man made hole, that is Jagersfontein Mine.
The diamonds found at Kimberly were formed in vertical pipes. Huge layers of rocks eroded, and so it is cut through by todays surface. The circular pipe reaches the surface right on the farm, two Dutch settlers bought in 1871. The two brothers called Johannes Nicolaas and Diederik Arnoldus de Beer soon discovered the diamonds on their ground. This lead to a diamond rush, which made it impossible for them to keep the land. They were not able to protect it from the growing tide of intruders, so they sold it. And although they did not become the owners of the mines, one of the mines inherited their name and until today the diamond trade is connected with their names. De Beers is the company which today controlls virtually all diamonds on Earth.
Today the Big Hole is about 215m deep, but 40m of ground water leave only 175m visible. Originally the hole was 240m deep, but after it was abandoned it was used to throw debris in. The underground Kimberly Mine was mined to a depth of 1097m.
The Diavik Diamond Mine is a diamond mine in the North Slave Region of the Northwest Territories, Canada, about 300 kilometres (186 miles) north of Yellowknife. It has become an important part of the regional economy, employing 700, grossing C$100 million in sales, and producing 8 million carats or about 1,600 kg (3,527 lb) of diamonds annually. The area was surveyed in 1992 and construction began in 2001, with production commencing in January 2003. It is connected by an ice road and Diavik Airport with a 5,235 feet (1,596 m) gravel runway regularly accommodating Boeing 737 jet aircraft.
The Great Blue Hole is a large underwater sinkhole off of the coast of Belize. It lies near the center of Lighthouse Reef, a small atoll 60 miles from the mainland and Belize City. The hole is almost perfectly circular, over 1,000 feet across and 400 feet deep. It was formed as a limestone cave system during the last ice age when sea levels were much lower. As the ocean began to rise again the caves flooded, and the roof collapsed.
This site was made famous by Jacques-Yves Cousteau who declared it one of the top ten scuba diving sites in the world. In 1971 he brought his ship, the Calypso to the hole to chart its depths.
