engleski

Orogenic signatures in Late Cenozoic volcanic rocks from the northern External Dinarides, Croatia

New petrographical and chemical data are reported for two unique occurences of Late Cenozoic post-collisional volcanic rocks from the northern External Dinarides. Basalts from Donje Pazariste (Lika zone) and basaltic andesites and absarokites (shoshonitic series) from Ljubac (Dalmatian, zone are characterized by trace element signatures typical for orogenic magmas such as negative Ta-Nb anomalies in primordial mantle-normalized element concentration patterns and high values of Th/Yb, Ba/Nb and La/Nb in combination with low Nb/Th and Ce/Pb. Relatively high Y and partly also Sc abundances in combination with low Tb/Yb ratios preclude garnet as a major fractionating phase and suggest a rather shallow mantle origin of the magmas. Magma mixing processes are indicated by clinopyroxene phenocrysts in basalts from Donje Pazariste that show complex chemical zoning with Fe, Ti and Na-rich cores and normally zoned Mg-rich mantles.

Volcanic rocks; Lika; Dinarides; Dalmatia

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