New Constraints on the Main Mineralization Event Inferred from the Latest Discoveries in the Bor Metallogenetic Zone (BMZ, East Serbia)

• Published in: Minerals (Basel) Vol. 9; no. 11; p. 672
• Main Authors: Miodrag Banješević, Vladica Cvetković, Albrecht von Quadt, Darivojka Ljubović Obradović, Nebojša Vasić, Aleksandar Pačevski, Irena Peytcheva
• Format: Journal Article
• Language: English
• Published: MDPI AG 01-11-2019
• Subjects: andesite; balkan peninsula; hydrothermal events; porphyry copper deposits; tethyan metallogenetic belt
• ISSN: 2075-163X
• DOI: 10.3390/min9110672

This study aims at better constraining the link between magmatism and metallogeny in the south-easternmost sector of the Bor Metallogenetic Zone (BMZ), where the world-class copper and gold deposit of Čukaru Peki was recently discovered. The obtained U/Pb zircon ages confirm the earlier knowledge that the major Cu−Au porphyry and epithermal mineralization in the BMZ is genetically related to the first volcanic phase ('Timok andesite'; 85−90 Ma). However, the data also suggest that during this phase, two subgroups of andesite porphyry were formed; they are named volcanic phase 1A (V1A) and volcanic phase 1B (V1B). The V1A andesite (89−90 Ma) is plagioclase-hornblende phyric, holocrystalline and ubiquitously hydrothermally altered and/or mineralized, whereas the V1B (85−86 Ma) is hornblende-plagioclase phyric, holo- to hypocrystalline, fresh, and non-mineralized. According to our simplified model, the contrasting productivity of the V1A and V1B is explained by fluctuations during AFC (assimilation-fractional crystallization) processes of water-rich parental magma, which have controlled the order of crystallization of hornblende and plagioclase in the V1A and V1B andesite.