Sierra de las Minas

Sierra de las Minas is a mountain range in eastern Guatemala, extending 130 km west of the Lake Izabal. It is 15–30 km wide and bordered by the valleys of the rivers Polochic in the north and the Motagua in the south. Its western border is marked by the Salamá River valley which separates it from the Chuacús mountain range. The highest peak is Cerro Raxón at 3,015 m.
The Sierra's rich deposits of jade and marble have been mined throughout the past centuries. These small scale mining activities also explain the name of the mountain range.
The range has several different habitats, including Mesoamerica's largest cloud forests, and is home to a great variety of wildlife. A large part of the Sierra de las Minas was declared a biosphere reserve in 1990.
Biosphere reserve
In 1990, a substantial part of the Sierra de las Minas (including buffer zones and transition areas) was designated a biosphere reserve.
Habitats and land cover types
Due to its size and great variety in elevation and precipitation, the range has many different habitats and land cover types, including:
Subtropical thorn forest, also known as Motagua Valley thornscrub, with Cactus species, Guaiacum species, Vachellia farnesiana and Bucida macrostachys.
Premontane dry subtropical forest with Encyclia diota, Ceiba aesculifolia and Leucaena guatemalensis.
Premontane tropical wet forest including Attalea cohune, Terminalia amazonia, Pinus caribaea and Manilkara zapota.
Lower montane subtropical moist forest with Pinus oocarpa, Quercus species, Alnus jorullensis and Encyclia selligera.
Cloud forest including Alfaroa costaricensis, Brunellia mexicana, Gunnera species, and Magnolia guatemalensis.
Agroecosystems with coffee, rice, maize, etc.
Pastures with Tillandsia species.
Fauna
The reserve has 885 species, about 70% of all species found in Guatemala and Belize, including threatened birds like the resplendent quetzal (Pharomachrus mocinno), harpy eagle (Harpia harpyja) and horned guan (Oreophasis derbianus).
Felines with a significant presence are the Jaguar (Panthera onca), Cougar (Felis concolor), Onza (Puma yagouaroundi), Ocelot (Leopardus pardalis) and Margay (Leopardus wiedii).
Other mammals in the reserve include the red brocket (Mazama americana), the Guatemalan black howler (Alouatta pigra) and Baird's tapir (Tapirus bairdii).
Jade Reserve
The southern area of Sierra de la Minas (translated in Spanish as the 'Mountain Range of the Mines’) is also known for its rich deposits of jadeite, (one of the two forms of jade) marble, serpentine, and other minerals. Smaller jadeite deposits have been rediscovered sporadically in the last 50 years, but it was not until 1998 that a major source was identified.
Jadeite is found all over the world, in countries such as Myanmar, New Zealand, Kazakhstan, Russia, British Columbia, United States, and Turkestan. The other form, nephrite, is much more common, but of much less value. Blue jadeite is similar in structure to the different colors of jadeite; it is the trace elements found in the minerals that contribute to their color. The blue jadeite, for example, is known to have traces of titanium and iron. Jadeite and nephrite artifacts found in the new world were at one point thought to have been from Asia.
The region of Sierra de Las minas, along with the Motagua river valley, was used by older pre-Columbian civilizations such as the Olmec and Maya as a source of jadeite. The jadeite was used for different purposes, such as for ritual objects and adornments. Because of their location between Mexico and Central America, the Maya became an important influence in Mesoamerican trade. Jadeite became an important export for the Maya, along with serpentine, salt and cacao. It was assumed that these cultures amassed all of their jade from the Motagua River valley, the then only known source of jadeite, in central Guatemala near El Portón.
Rediscovery
Because jade was not desired in the colonial period, sources of the stone were forgotten. Since the 1950s, jadeite was thought to be in the region, as no other source for Olmec jade was recognized. It was not until 1999 when geophysicist Russell Seitz found and reported the site that the extent of these deposits was known. Several influences in the United States spurred the search for this jade. Boston jade collector Landon T. Clay was one of the first individuals to sponsor the search for jade in the region. The Mesoamerican Jade Project of 1976 was initiated by the Peabody Museum of Harvard University and the Boston Museum of Fine Arts, to resolve the question of the jade's location. Geophysicist Russell Seitz of Cambridge, Massachusetts was chosen to be the field director of the project. However, the resulting trips remained mostly unsuccessful due to the lack of proper technology and the harsh conditions of the wild Guatemalan forests.
It was not until the 180 mph winds of Hurricane Mitch stormed the region in 1998 that jadeite was again uncovered in the area. The storm unearthed previously unknown alluvial deposits of jadeite by flooding the Motagua River thirty-one feet past the flood stage. Other rivers such as the Rio El Tambor also began unveiling alluvial jade. Although the worth of this jade was fairly low (the more intense the green of the jade the more it is worth), prospectors and local shop owners began collecting shards found in the beds of these rivers. In 1999, Russell Seitz happened to be in one of these local jade shops in the town of Antigua when he noticed a large hand-sized sample of the rare blue-jadeite.
In 2000, Seitz started an expedition with prospector Carlos Gonzales Ramirez to find the source of the elusive jadeite. They traveled to El Ciprés, located in Sierra de Las Minas, miles north of the Motagua river valley. They trekked into the mountains and eventually found large veins of jadeite about 2 meters wide by 45 meters long. A site with jade boulders as big as buses was discovered, along with evidence that the site had been worked on for thousands of years.
When Seitz returned to the United States with a few samples, he had them tested and they were confirmed as high quality jadeite. This spurred more researchers to join him in his study of this site. The find was announced in a brief article written by Seitz for the December 2001 issue of Antiquity.
The archaeological connotation of the find was significant. The influence of the Olmecs was understood to be more spread than previously believed. Also found at the site was an ancient dry-stone pathway that led through the mountains to an old habitation and tomb site, filled with the remains of old clay shards. This road has expanded the preconceived size of the Olmecs' trade routes. It is still debatable as to why exactly this large cache of jadeite is still mostly intact. The Maya were known to use the green form of the jadeite for their carvings. And because the Spanish only sought the gold, the Olmecs would have had all the blue jadeite to themselves.
The Motagua valley is another source of jade in the area. The town of Río Hondo and its surrounding areas have yielded finds such as the "princesa" variety of jadeite. This valuable type of jadeite contains a translucent rich-green color. In 1996 prospector Carlos Gonzalez began searching the area for jade. He discovered a 140 lb boulder of jadeite that had a translucent, light blue color. The 7 km area from La Ceiba to Carrizal Grand contained similar Omec jade artifacts. Gonzales and colleagues discovered more examples in the southern tributaries of the Rio El Tambor located near Carrizal Grande and San José. In January 2002 they were led to the locality of Quebrada Seca, where they were shown a jade boulder that weighed in excess of 300 tons. Other archeologists such as François Gendron of France and Dr. Richard Mandell of the University of South Carolina began unearthing more samples of jadeite in the region. Gendron discovered a jadeite sample with a composition suggesting it was formed 80 to 90 km underground, much more than the expected 20 km, around which jadeite is usually known to form.
References
External links
Fundación Defensores de la Naturaleza
Description of Sierra de las Minas biosphere reserve
UNESCO data on the Sierra de las Minas biosphere reserve
Parkswatch
Minas
Biosphere reserves of Guatemala
Geography of Mesoamerica