Tertiary migmatic pegmatites in the Central Rhodope crystalline complex. Uranium-lead zircon dating

Pages: 
pp. 25-32
Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
Institute of Nuclear Research and Nuclear Energetics, Bulgarian Academy of S ciences, 1184 Sofia
Institute of Nuclear Research and Nuclear Energetics, Bulgarian Academy of S ciences, 1184 Sofia
Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
Abstract: 

The formation of bedded migmatic pegmatites in the presumably Precambrian high-metamorphic complex along the Vacha River south of the town of Krichim in the Central Rhodope Mts is the result of ultrametamorphic processes which took place in Alpine times. The U-Pb age of zircons from zircon- and allanite-rich migmatic pegmatites is Young Alpine, 58-49 Ma, according to analyses in two radiogechronological laboratories, one in Sofia, Bulgaria, and the other in Amsterdam, Holland. These values are close to the U-Pb ages obtained for uraninites from rare-metal pegmatites (53-49 Ma) crosscutting the high-metamorphic series near the village of Dolen, Zlatograd district. The mineralogical, geochemical and radioisotope evidence gained on the bedded and cross pegmatites in the metamorphic rocks of the so-called Rhodope Supergroup is inconsistent with the idea of a Precambrian ult rametamorphic series in the Central Rhodope Mts.

VOLUME 20 (6)/December 1990

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria

Deparlmenl of Geography and Climatology, Universily of Athens, 15784 Athens, Greece
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Deparlmenl of Geography and Climatology, Universily of Athens, 15784 Athens, Greece

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Institute of Nuclear Research and Nuclear Energetics, Bulgarian Academy of S ciences, 1184 Sofia
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Institute of Nuclear Research and Nuclear Energetics, Bulgarian Academy of S ciences, 1184 Sofia
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria

Department of Geology, University of Patras, 261 10 Partas, Greece

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria

Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia
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Scientific Institute for Mineral Deposits, 1505 Sofia