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Mapimí, Durango, México
In the limits where the states of Chihuahua, Coahuila and Durango converge, the Mapimí Biosphere Reserve is situated. In its 350 hectares is the mysterious Zona de Silencio where numerous meteors are fallen. There is a strong subterranean magnetic charge making it difficult to capture radio or television signals. Although it would appear to be an indomitable area, this semi arid land possesses an interesting wildlife, numerous archaeological and historical remains, fossil deposits, rock paintings, colonial haciendas and, in the middle of all these wonders, the old mining town Ojuela, with its splendid suspension bridge. This amazing place is seated at the foot of La Bufa or Cerro de la India, (Hill of the Indian) since its outline resembles that of a human figure. At the time of the Spanish Conquest, there existed a town inhabited by the Cocoyon Indians, called Mapemes, which means “high stone”. Over the years the name degenerated to Mapimi by which it is known today. During the period of excavations, the district produced six million tons of minerals rich in silver and one million tons of sulphides. The glory was short lived and with the onset of the Revolution in 1910 and the poorness of the mineral veins, the mine was reduced to a workforce of around 100 miners. Today all that remains are the ruins of the mining town and the enormous suspension bridge that connects the two mountains.
This suspension bridge is considered to be an engineering marvel, the only one of its kind in Latin America. It was a monumental accomplishment for the time, measuring 318 metres in length and almost two metres wide. In 1896, Santiago Minguin, a German constructor and designer, designed two towers that were sunk into the rock bed and held the bridge without any support. Originally the towers were made of timber and were 17 metres high, they have now been rebuilt in stone. At its highest point above the valley below, it measures 180 metres in height. Minguin also designed The Golden Gate Bridge that spans the Bay of San Francisco, California.
Calcita de Mapimí, Durango, MéxicoLuis Lyons photo
Hemimorfita de MapimíLuis Lyons photo
Rosasita de MapimíLuis Lyons photo
The Ojuela mine became well known internationally because of articles and comments made by the mineralogist W. F. Foshag, who found many fascinating specimens when he visited the location. In 1946, Dan Mayers and Francis Wise made a series of important finds in particularly exquiste specimens of adamite. Over the years, minerals have continued to be extracted and today 117 different species are now known. Included in these are the best examples of adamite in the world, legrandite, paradamite, scorodite and hemimorphite.
The mine is a labyrinth of 450 kilometres of underground tunnels. Work ceased here in 1945 but the fame of its specimens continued due to the fact that a co-operative carried on extracting minerals. Under an arrangement with Peñoles, gold and other collectable specimens continues to be extracted. The discovery of the first great specimen of adamite in 1946 fostered the continuation of work on levels four and five of the mine, by the co-operative miners. Legrandite, yellow adamite and the highly sought after purple adamite, began to circulate in the market. At the beginning of the XXI century, the discovery of aragonite rekindled interest in the region.
The district of Mapimí corresponds to a geology typically made up of carbonated rocks that were formed during the Mesozoic period. This same geological event influenced the locations of Santa Eulalia, Naica, San Pedro Corralitos and Los Lamentos. A series of intricate underground rainwater rivers overtaken by hydro-mineral fluids that emerged from the rocks by effects of magnetism procreated the mineralization of the veins. Even though the land is arid there is an abundance of water in its rocky interior.
The Ojuela mine has given a number of different species of adamite, so many in fact, that today it is the most prolific place in the world for this mineral. These crystals that go from dark brown to greenish yellow, are generally found radiating from their matrix and often associated with calcite, smithsonite and legrandite. The most prized and rare specimens from this location were the specimens of purple adamite found in the mid 1970’s.
The minerals found in this mine have been coarse minerals; apatite, anglesite, dragonite, arsenopyrite, austenite, azurite, barite, calcite, aurichalcite, fluorite, hemimorphite, mimetite, paradamite, rosasite, smithsonite and wulfenite are some, but none as rare and beautiful as legrandite. The unique crystals of legrandite are found on levels five and six of the Ojuela mine and apart from the deposits in Nambia, Africa, Ojuela is the only other place where they have been found. These crystals are usually long and brilliant straw colour that rise majestically in cascades, and are the most appreciated by collectors and museums.
Today, the Mapima Suspension Bridge is still standing waiting for a new bonanza. There are various projects for the recovery of the region in the pipeline, irrespective of the outcome, the region will not only continue to be renown for its magnificent minerals but also its tranquil beauty.