Dominican amber
Dominican amber is found on the island of Hispaniola , almost exclusively in the territory of the Dominican Republic . Among the amber deposits in the world, the Dominican amber has the greatest importance after the Baltic amber in terms of its wealth of fossil inclusions . In 1987 the government in Santo Domingo decreed that amber fossils could only be taken out of the country with the express permission of the National Museum of Natural History, but this is not taken so seriously. Nevertheless, the collection of the State Museum for Natural History ( Löwentormuseum ) in Stuttgart is probably the most important scientific collection of Dominican amber with organic inclusions worldwide.
In addition, the popularity of Dominican amber is based on the large number of clear pieces, which are ideal for making jewelry, and its variety of colors, including the rare "blue amber", whose "color" is due to fluorescent molecules. One of several explanations offered for the origin of this color variant is a subsequent heating of the fossil resin as a result of volcanic activity. Another explanation is that widespread forest fires may have led to this change. The blue fluorescent Dominican amber has nothing to do with the blue pectolite found in the Barahona area and sold as a gemstone under the name Larimar .
The amber is mainly mined by hand in pits and tunnels. Very small amounts can be traced back to the present day from beach finds , especially on the stretch of coast near Puerto Plata known as Costambar (amber coast). Sometimes very large individual items weighing several kilograms are found.
Deposits and ages
The amber in the Cordillera Oriental and Cordillera Septentrional areas of Hispaniola is stored in Tertiary sandstone. Based on drilling, it is believed that there are still considerable amounts of amber. The Cordillera Septentrional are predominantly covered by sedimentary rocks of tertiary age. Most of the amber mines in this mountainous region occur in the La Toca Formation (Poinar uses the term "Altamira facies of the El Mamey Formation"). This formation is a slate - sandstone interspersed with conglomerates of rounded pebbles . Organic material and extensive coals often appear, with the amber lying in lignitic sandstone or the lignite veins. On the basis of coccoliths , the age of the slate and sandstone from El Mamey was determined to be 40 million years (Upper Eocene). Iturraldo-Vinent points out that all amber mines in the Dominican Republic are located in the La Toca Formation, which dates back to around 15 to 20 million years (Middle Miocene), and the Yanigua Formation, which is about the same age. According to some authors (not undisputed), the amber found on the Miocene deposit was partially relocated. Paleoentomological studies show that Dominican amber is definitely younger than Baltic amber. Small amounts of amber found in Miocene-age coal deposits on the neighboring island of Puerto Rico are probably of the same origin as Dominican amber. On the other hand, amber found in Jamaica was dated to the Maastrichtian / Paleocene .
Resin producer
Based on the vegetable finds in amber, it is assumed that the resin from which Dominican amber was created was produced by the tree Hymenaea protera . This fossil legume species most closely resembles the recent tree Hymenaea verrucosa , which occurs in East Africa and the offshore islands. A related species ( Hymenaea courbaril ) is still found in the Dominican Republic, the local name is algarrobo . Investigations using infrared spectroscopy , nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry have confirmed the similarity of Dominican amber to the resin of recent Hymenaea species, in particular Hymenaea verrucosa .
history
Historical accounts of amber in the Dominican Republic can be traced back to the diaries of Christopher Columbus . Reports about Indian jewelry made of amber appear again and again. The first indications of organic inclusions in Dominican amber date back to 1939. In the 1930s, a company from the USA also tried to mine Dominican amber, but stopped its activities when the tunnel collapsed after a water ingress. Dominican amber only came onto the German market in the 1970s.
Amber mining in Hispaniola
The amber-leading formations extend over both states (Dominican Republic and Haiti ) of the Caribbean island. Systematic mining of amber is only known from the Dominican Republic. Although the occurrences in Haiti are probably also not inconsiderable, little information is available on this. It is certain that amber was found in a lignite deposit in the central plateau of Haiti.
Mining in the Dominican Republic extends to the area around Puerto Plata and Santiago (Cordillera Septentrional) and - further east - near Bayaguana in the Cordillera Oriental. In the vicinity of La Toca (northeast of Santiago), the amber is extracted from open pits as well as from shallowly sloping narrow tunnels driven into the slope with a depth of up to 100 meters by being knocked out of the bedrock. Such tunnels are usually exploited within three years. The pits and tunnels are built in a disorganized way, are insufficiently secured and, especially in the rainy season, often run full of water. Amber is extracted in a similar way in almost all other mining areas in the mountainous region of the Dominican Republic. The pits in the area of Palo Alto (north of Santiago) are considered to be particularly productive. In the Cordillera Oriental, the coveted material is also extracted from duck mining . Such shafts are usually exploited within a few weeks. Reliable information on the number of actively operated pits, tunnels and shaft systems is not available. It is estimated, however, that around 3,000 workers are involved in amber mining, many of them only seasonally. Since there are usually significantly fewer than ten people employed in a plant, the number of active "mines" is likely to be in the hundreds, while the number of abandoned mines is probably in the thousands.
Economic importance for the country
In addition to the more or less regular employees in the "mines" (approx. 3000), between 500 and 1000 craftsmen are employed in processing the raw material. The number of people regularly employed in sales goes well in excess of 1,000. The total production in a year is subject to large fluctuations, but does not exceed five tons. Although this amount only accounts for around 1% of the production volume of Baltic amber, from a commercial point of view, Dominican amber is the most important in the world after Baltic amber.
Individual evidence
A large part of the information in this article comes from the sources given under literature, and the following sources are also cited:
- ↑ Vittorio Bellani, Enrico Giulotto, Laura Linati, Donatella Sacchi: Origin of the blue fluorescence in Dominican amber . In: Journal of Applied Physics . tape 97 , no. 1 , 2005, p. 016101-2 , doi : 10.1063 / 1.1829395 .
- ^ D. Penney: Dominican Amber. In: Biodiversity of fossils in amber from the major world deposits. Ed. D. Penney, Manchester 2010, ISBN 978-0-9558636-4-6 , pp. 22-41.
- ↑ David A. Grimaldi: Amber - Window to the Past. New York 1996, ISBN 0-8109-2652-0
- ↑ George O. Poinar, Jr .: Life in Amber. Stanford University Press, Stanford (Cal.) 1992.
- ↑ a b Manuel A. Iturralde-Vinent: Geology of the Amber-Bearing Deposits of the Greater Antilles. - Caribbean Journal of Science, Vol. 37 (3-4), University of Puerto Rico, Mayagüez, 2001
- ↑ David A. Grimaldi: The Age of Dominican Amber. In: Amber, Resinites, and Fossil Resins. ACS Symposium Series 617, Washington, DC, 1995.
- ↑ M .W. Sanderson and TH Farr: Amber with insects and plant inclusions from the Dominican Republic. In: Science 131 (1960); quoted in George O. Poinar: Life in amber. Stanford 1992.
- ↑ a b M. Whole Levski: Amber mining in the Dominican Republic. In: Amber - Tears of the Gods. Bochum 1996.
literature
- George Poinar Jr. & Roberta Poinar: The Amber Forest - A Reconstruction of a Vanished World. Princeton 1999.
- D. Schlee: Special features of the Dominican amber. In: Stuttgarter Beitr. Naturk. C, 18, Stuttgart 1984, pp. 63-71.
- David Penney: Dominican Amber. In: Biodiversity of fossils in amber from the major world deposits. Manchester (UK) 2010, pp. 22-41. ISBN 978-0-9558636-4-6 .
- Rafael Jie Chiang Wu: Secrets of a lost world - Dominican Amber and its inclusions. Santo Domingo (Dominican Republic) 2007.
