Lehmann, Stephan and Barcikowski, Joshua and von Quadt, Albrecht and Gallhofer, Daniela and Peytcheva, Irena and Heinrich, Cristoph and Serafimovski, Todor (2013) Geochronology, geochemistry and isotope tracing of the Oligocene magmatism of the Buchim–Damjan–Borov Dol ore district: Implications for timing, duration and source of the magmatism. LITHOS, 180/1 (1). pp. 216-233. ISSN 0024-4937
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Abstract
Timing, source and magmatic evolution of the intrusions in the Buchim–Damjan–Borov Dol ore district of the
Former Yugoslav Republic of Macedonia (F.Y.R.O.M.) have been studied. They intrude the Circum Rhodope Unit
close to the contact with the Vardar Zone and are a part of the Late Eocene–Oligocene Macedonian Rhodope–
North Aegean belt. The magmatism at Buchim–Damjan–Borov Dol occurred between 24.04 ± 0.77 and
24.51 ± 0.89 Ma, as indicated by chemical-annealing (CA)–LA ICP-MS zircon dating. Major element, trace and
rare earth element analyses have been performed on the various intrusive rocks. All ore bearing magmas were
classified as trachyandesitic, except the youngest intrusion which is not associated with mineralization; the
Black Hill locality (24.04 ± 0.77 Ma) shows a trachytic composition. The distribution of the trace elements,
enrichment of large ion lithophile elements (LILE) and depletion in high field strength elements (HFSE), indicates
subduction-related magmatism; most of the magmas follow a calc-alkaline fractionation trend with shoshonitic
affinities; additionally, Sr/Y (10 to 90) and La/Yb values show somesimilarities to adakite-likemagmas. Sr and Nd
isotope ratios (Sri = 0.70658 to 0.70740 and Ndi = 0.512425–0.512497) showthat themagmatic productswere
slightly contaminated by continental crust material, e.g., the Variscan/Cadomian basement. In the Late Eocene–
Oligocene belt the magmatism between 29 and 35 Ma is dominated by crustal melting with an increase in the
mantle contribution between 20 and 27 Ma. We suggest the following scenario for the magmatic history of the
Buchim–Damjan–Borov Dol ore district: a slab rollback of an oceanic slab located further to the SW which led
to extensional and compressional features in upper levels of the continental crust. In the middle to upper crust
three consecutive crystallization stages occurred at variable depths as indicated by amphibole zonation. Mixing
of newly formed crust with mantle-like affinities and continental crust material in variable degrees during the
ascent of the magma can explain all geochemical characteristics. The magma crystallized as dykes or stocks
near the Earth's surface (>1 km) after its final emplacement and contemporaneous hydrothermal activity led
to different mineralization styles depending on the lithology of the host rocks.
| Item Type: | Article |
|---|---|
| Subjects: | Natural sciences > Earth and related environmental sciences |
| Divisions: | Faculty of Natural and Technical Sciences |
| Depositing User: | Todor Serafimovski |
| Date Deposited: | 23 Jan 2014 10:47 |
| Last Modified: | 23 Jan 2014 10:47 |
| URI: | https://eprints.ugd.edu.mk/id/eprint/8775 |
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