The western side of the Vertiskos Unit crystalline basement in northern Greece is fringed by a Permo–Triassic low-grade metamorphic volcano-sedimentary complex that belongs to the Circum-Rhodope Belt (CRB), which is an important part of the Vardar/ Axios oceanic suture zone. The silicic volcanic rocks from the CRB are mainly rhyolitic to rhyodacitic lavas with aphyric and porphyritic textures as well as pyroclastic deposits. In this study, geochemical data obtained with X-ray fluorescence (XRF) for the CRB silicic volcanic rocks are reported and discussed to constrain their petrogenesis and tectonic setting. The rocks are peraluminous and show enrichment in K, Rb, Th, Zr, Y, and Pb while being depleted in Ba, Sr, Nb, P, and Ti, and they have Zr + Nb + Y + Ce > 350 ppm, which are characteristic features of anorogenic A-type granites. They have a Y/Nb ratio > 1.2 and belong to A2-subtype granitoids, implying crust-derived magma in a post-collisional tectonic setting. The high Rb/Sr ratio (3.45–39.14), the low molar CaO/(MgO + FeO_t) ratio, and the CaO/Na₂O ratio (<0.5), which they display, indicate that metapelites are the magma sources. Their low Al₂O₃/TiO₂ ratio (<100), consistent with their high zircon saturation temperatures (average T_Zr = 886 °C), and their low Pb/Ba ratio (average 0.06) reveal that they were generated by biotite dehydration melting. The increased Rb/Sr ratio relative to that of presumable parental metapelites of the Vertiskos Unit, coupled with their low Sr/Y ratio (0.12–1.08), reflects plagioclase and little or no garnet in the source residue, indicating magma derivation at low pressures of 0.4–0.8 GPa that correspond to a depth of ~15–30 km. The nearby tholeiitic basalts and dolerites, interstratified with the Triassic pelagic sediments, indicate bimodal volcanism in the region. They also support a model involving an upwelling asthenosphere that underplated the Vertiskos Unit basement, supplying the heat required for crustal melting at low pressures. The Permo–Triassic magmatism marks the transition from an orogenic to an anorogenic environment during the initial stage of continental breakup of the Variscan basement in a post-collision extensional tectonic framework, leading to the formation of the nascent Mesozoic Neo-Tethyan Maliac–Vardar Ocean. This apparently reveals that the Variscan continental collision between the Gondwana-derived Vertiskos and Pelagonian terranes must have been completed by at least the earliest Late Permian.

Coal bottom ash is used globally in various applications in the construction industry to reduce its negative environmental impacts. In this study, the potential utilization of lignite bottom ash from four power plants in Greece in concrete manufacturing was evaluated through granulometric, chemical, and mineralogical analyses. The particle-size distribution of bottom ash obtained from dry sieving resembles that of sand, making bottom ash suitable for replacing fine aggregates in the production of concrete. Its chemical composition, determined with selective point analyses energy dispersive spectroscopy (EDS), reveals high amounts of silica and alumina indicating pozzolanic properties, and high calcium contents suggesting hydraulic/cementitious character. Mineralogical characterization, obtained from powder X-Ray diffraction analyses (XRD), displays the prevalence of amorphous matter, calcite, quartz, aluminosilicate minerals, and portlandite, implying a beneficial pozzolanic and hydraulic activity in concrete manufacturing.

This study investigates the potential of selected plant species for environmental restoration and phytostabilisation in lignite mine waste dumps in Western Macedonia, Greece. Field sampling was conducted in three representative sites, where both soil and plant tissues were collected and analysed using X-ray Fluorescence (XRF). A total of six species (Pinus spp., Acacia spp., Populus spp., Cupressus spp., Cuprocyparis leylandii, and Tamarix spp.) were evaluated for their ability to grow in low-fertility substrates and their capacity to accumulate potentially toxic elements (PTEs). The findings indicate that soil chemistry is primarily influenced by geogenic factors, with elevated concentrations of Ca, Si, Mg, and K, consistent with the carbonate-rich geology of the Ptolemaida basin. Concentrations of PTE (Ni, Cr, Zn, Pb) remain below established toxicity thresholds, and Hg levels are negligible (<0.03 mg/kg). Plant tissue analysis revealed selective nutrient uptake and limited translocation of PTEs to aerial parts. Although the studied species do not exhibit hyperaccumulator characteristics necessary for phytomining, they exhibit strong phytostabilisation capacity, supporting erosion control and ecological restoration without increasing environmental risk.