Dominican amber differentiates itself from Baltic amber by being nearly always transparent, and it has a higher number of fossil inclusions. This has enabled the detailed reconstruction of the ecosystem of a long-vanished tropical forest.[1]
The age of the amber has been controverisal. A study in the early 1990s returned a date up to 40 million years old.[2] However, other authors have suggested a date in the Miocene, around 20-15 million years old, based on marine microfossils found in the sediment the amber is contained in.[3]
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 fragments and other sediments that accumulated in a deltaic environment, even in water of some depth.[4][5][6]
In the eastern area, the amber is found in a sediment formation of organic-rich laminated sand, sandy clay, intercalatedlignite, and as well as some solvated beds of gravel and calcarenite.[7]
Both areas seem to have been part of the same sedimentary basin but were later disrupted by movements along major faults.[8]
Dominican amber, especially Dominican blue amber, is mined through bell pitting, which is extremely dangerous. The bell pit is basically a foxhole dug with whatever tools are available. Machetes do the start, some shovels, picks and hammers may participate eventually. The pit itself goes as deep or safe as possible, sometimes vertical, sometimes horizontal, but never level. It snakes into hill sides, drops away, joins up with others, goes straight up and pops out elsewhere. 'Foxhole' applies indeed: rarely are the pits large enough to stand in, and then only at the entrance. Miners crawl around on their knees using short-handled picks, shovels and machetes.
There are little to no safety measures. A pillar or so may hold back the ceiling from time to time but only if the area has previously collapsed. Candles are the only source of light. Humidity inside the mines is at 100%. Since the holes are situated high on mountainsides and deep inside said mountains, the temperature is cool and bearable, but after several hours the air becomes stale. During rain the mines are forced to close. The holes fill up quickly with water, and there is little point in pumping it out again (although sometimes this is done) because the unsecured walls may crumble.[9]
Dominican amber can be found in many colors, besides the obvious amber. Yellow and honey colored are fairly common. There is also red and green in smaller quantities and the rare blue amber (fluorescent).[10][11]
The blue amber reportedly is found mostly in Palo Quemado mine south from La Cumbre.[12][13]
The Museo del Ambar Dominicano, in Puerto Plata, as well as the Amber World MuseuminSanto Domingo have collections of amber specimens.
^Leif Brost and Ake Dahlstrom. The Amber Book, Geoscience Press, Inc., Tucson , AZ, 1996 ISBN0-945005-23-7
^Wilfred Wichard und Wolfgang Weitschat: Im Bernsteinwald. - Gerstenberg Verlag, Hildesheim, 2004, ISBN3-8067-2551-9
^Baroni Urbani, C. & Saunders, J.B. (1980): The fauna of the Dominican Republic amber: the present status of knowledge. – Memorias, 9a geologica del Caribe, 1: 213–223; Santo Domingo. (Published 1983).
^Schlee, D. (1984): Besonderheiten des Dominikanischen Bernsteins. – Stuttgarter Beitr. Naturk., C, 18: 63-71; Stuttgart.
^Manuel A. Iturralde-Vennet 2001. Geology of the Amber-Bearing Deposits of the Greater Antilles. Caribbean Journal of Science, Vol. 00, No. 0, 141–167, 2001
^Martínez, R. & Schlee, D. (1984): Die Dominikanischen Bernsteinminen der Nordkordillera, speziell auch aus der Sicht der Werkstaetten. – Stuttgarter Beitr. Naturk., C, 18: 79-84; Stuttgart.
^Poinar, G. (2005). "Triatoma dominicana sp. n. (Hemiptera: Reduviidae: Triatominae), and Trypanosoma antiquus sp. n. (Stercoraria: Trypanosomatidae), the First Fossil Evidence of a Triatomine-Trypanosomatid Vector Association". Vector-Borne and Zoonotic Diseases. 5 (1): 72–81. doi:10.1089/vbz.2005.5.72. PMID15815152.
^Poinar, G. O.; Peterson, E. B.; Platt, J. L. (2000). "Fossil Parmelia in new world amber". The Lichenologist. 32 (3): 263–269. doi:10.1006/lich.1999.0258. S2CID86227172.
^De Andrade, M. L. (1998). "First description of fossil Acanthostichus from Dominican amber (Hymenoptera: Formicidae)". Mitteilungen der Schweizerischen Entomologischen Gesellschaft. 71: 269–274.
^ abcdefghDe Andrade, M. L. (1994). "Fossil Odontomachiti Ants from the Dominican Republic (Amber Collection Stuttgart: Hymenoptera, Formicidae. VII: Odontomachiti)". Stuttgarter Beiträge zur Naturkunde. Serie B (Geologie und Paläontologie). 199: 1–28.
^MacKay, W. P. (1991). "Anochetus brevidentatus, new species, a second fossil Odontomachiti ant (Hymenoptera: Formicidae)". Journal of the New York Entomological Society. 99: 138–140.
^Baroni Urbani, C. (1980). "Anochetus corayi n. sp., the first fossil Odontomachiti ant. (Amber Collection Stuttgart: Hymenoptera, Formicidae. II: Odontomachiti)". Stuttgarter Beiträge zur Naturkunde. Serie B (Geologie und Paläontologie). 55: 1–6.
^ abSchultz, T.R. (2007). "The fungus-growing ant genus Apterostigma in Dominican amber". Memoirs of the American Entomological Institute. 80: 425–436.
^Poinar, G.O. (2011). "The Evolutionary History of Nematodes: As Revealed in Stone, Amber and Mummies". Nematology Monographs and Perspectives Pages. 9: 91–93, 239–240, 324–325.
