Delineating petrological feature and geochemical characteristics of volcanic rocks from the Herson-Kilkis Area, Northern Greece

Abstract The geochemical data of this study confirm a previous suggestion that the Herson—Kilkis rhyolites are the crystallization products of a magma generated by the partial fusion of K-rich schists or para-gneisses and erupted along a dip-slip fault at the western boundary of the Serbo—Macedonian massif. High-K rhyolites occur in the area around Kilkis town along the western boundary of the Serbo-Macedonian massif. The chemistry of the rocks is characterized by high K2O contents (7–12 Wt %), high K2O/Na2O ratios (2–22), low CaO (0.04–0.16%) and Sr (0–83 mg Kg−1) contents and high Rb/Sr ratios (4–40). The trace elements (in mg Kg−1), Nb (Not Detected–41), Nd (5–87), Ce (16–119), La (9–67), Rb (Not Detected–358) and Y (10–87) present higher contents than those of rhyolites derived from a more basic magma by low-pressure fractional crystallization.