engleski

The Miocene Western Balkan lithium-boron metallogenic zone

The Western Balkan lithium-boron metallogenic zone can be traced for 1500 km, extending subparallel to the Sava-Vardar and Western Vardar zones toward its Turkish counterpart, the Izmir-Ankara-Erzincan zone. Common features are: (1) lithium-boron mineralization is hosted in Lower-Middle Miocene extensional lacustrine basins ; (2) lacustrine series consisting of fine-grained siliciclastic sediments and scarce evaporites with intercalations of volcaniclastics, tuff, or travertine indicating syndepositional volcanic activity ; (3) lacustrine basins that are usually normal-fault-controlled extensional grabens, with the fault system probably acting as a major fluid pathway ; (4) northernmost sodium borate/borosilicate deposits (Jadar, Valjevo, Rekovac ; with jadarite, borax, probertite, searlesite) gradually transition to calcium borate deposits southward (Jarandol-Piskanja, Pobrđe ; with colemanite ± ulexite) ; (5) Oligocene/Miocene granitic rocks from the westernmost part of the zone host pegmatite and greisen occurrences with surface lithium anomalies of 0.02–0.08 wt% Li2O extending for several km2 ; (6) igneous Li enrichment by fractionation processes is indicated for some younger (?Early/mid-Miocene) peraluminous granite plutons ; (7) the formation of the lacustrine basins and associated Li-B mineralization was contemporaneous with the emplacement of the younger phase of Li-bearing granitic intrusions and exhumation of metamorphic core complexes which provided the large-scale heat flow for hydrothermal systems and syngenetic Li-B mineralization.

Lithium-boron mineralization ; Extensional setting ; Li-bearing granitic rocks ; Miocene lacustrine basins ; Sava-Vardar zone ; Izmir-Ankara-Erzincan zone

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