Sunday, September 2, 2007

Dominican amber

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Dominican amber

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Dominican amber is amber from the Dominican Republic. Dominican amber differentiates itself from Baltic amber by being nearly always transparent, and it has the higher number of fossil inclusions, which have enabled the detailed reconstruction of the ecosystem of a long-vanished tropical forest (Poinar 1999). It is also the youngest amber found: from Oligocene to Miocene, 10 to 30 million years old. Resin from the extinct species Hymenaea protera is the source of Dominican amber and probably of most amber found in the tropics.

There are three main sites in the Dominican Republic where amber is found: La Cordillera Septentrional, in the north, and Bayaguana and Sabana de la Mar, in the east. In the northern area, the amber-bearing unit is formed of clastic rocks, washed down with sandstone and other sediments that accumulated in a deltaic environment, even in water of some depth.

In the eastern area, the amber is found in a sediment formation of organic-rich laminated sand, sandy clay, intercalated lignite as well as some solvated beds of gravel and calcarenite.

Both areas seem to have been part of the same sedimentary basin but were later disrupted by movements along major faults. (Iturralde-Vincent and MacPhee, 1996).

According to Poinar, 2001, Dominican amber dates from Oligocene to Miocene, up to 30 Mya old. The oldest, and hardest of this amber comes from the mountain region north of Santiago. The La Cumbre, La Toca, Palo Quemado, La Bucara, and Los Cacaos mining sites in the Cordillera Septentrional not far from Santiago. There is also amber in the south-eastern Bayaguana/Sabana de la Mar area. There is also copal found with only an age of 15-17 million years.

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[edit] Mining

Amber mine
Amber mine

Since the amber in these mountains is tightly imbedded in a lignite layer of sandstone with a high carbon content, the digging is made between the harder strata, which in some sites has been pushed up by orogenic forces to uneven angles. The result of this is that mines are usually just angled holes, dug into the sides of cliffs. The miners accomplish their work only with the help of primitive, simple tools and risk their lives daily.

[edit] Variations

Dominican amber can be found in many colors, besides the obvious amber. Red, green, yellow, orange and even blue amber are fairly common.

The Museo del Ambar Dominicano, in Puerto Plata, has a collection of amber specimens, including many with fossils.

[edit] External links

[edit] See also

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