The Maronia pluton, a high-K intrusion in the Circum Rhodope Belt, comprises gabbro to monzonite to granite having pyroxene, biotite and less olivine and amphibole. Three rock groups have been recognised: a basic, an intermediate and an acid. Major, trace and REE geochemistry as well as Sr and Ο isotopes support a genetic relation between the basic and the intermediate group but not between them and the acid group. An AFC process with a carbonate assimilant or an MFC process, where the basic end-member is represented by the less evolved samples, and the acid end-member by more evolved samples having Sr isotopes higher than those in the acid group, is suggested for the evolution of the basic-intermediate group. The basic-intermediate group originates from a lithospheric mantle while the acid group probably from a low-Sr isotopes crustal melt.
Abstract The Mt Cer Pluton, Serbia, is a complex laccolith-like intrusion (~ 60 km 2 ), situated along the junction between the southern Pannonian Basin and northern Dinarides. It intrudes Palaeozoic metamorphic rocks causing weak to strong thermal effects. Based on modal and chemical compositions, four rock-types can be distinguished: (1) metaluminous I-type quartz monzonite/quartz monzodiorite (QMZD); (2) peraluminous S-type two-mica granite (TMG), which intrudes QMZD; (3) Stražanica granodiorite/quartz monzonite (GDS); and (4) isolated mafic enclaves (ME), found only in QMZD. 40 K– 39 Ar dating and geological constraints indicate that the main quartz monzonite/quartz monzodiorite body of Mt Cer was emplaced not later than 21 Ma, whereas the emplacement ages of the Stražanica granodiorite/quartz monzonite and two-mica granites are estimated at around 18 and 16 Ma, respectively. The Mt Cer pluton is similar to the Mt Bukulja pluton, some 80 km southwestwards. Genesis of QMZD cannot be interpreted by fractional crystallization coupled with mixing or assimilation. It is best explained by a convection–diffusion process between mantle-derived minette/leucominette magmas and GDS-like magmas followed by two end-member magma mixing. The composition of GDS rocks suggests that GDS-like magmas could have formed by melting of lower crustal lithologies similar to amphibolite/metabasalts. The geochemistry of TMG is reproduced by an Assimilation/Fractional Crystallization model with a ratio of rate of assimilation to rate of fractional crystallization of 0.4, using the compositions of the least evolved TMG of the Bukulja pluton and adjacent metamorphic rocks as proxies for the parental magma and contaminant, respectively. The origin and evolution of the Mt Cer and adjacent Mt Bukulja plutons provide new constraints on the Tertiary geodynamics of the northern Dinarides–southern Pannonian region. The quartz monzonite/quartz monzodiorite is interpreted as a result of the Oligocene post-collisional Dinaride orogen-collapse, which included a limited lithosphere delamination, small-scale mantle upwelling, and melting of the lower crust. By contrast, the two-mica granite magmas formed through melting in shallower crustal levels during the extensional collapse in the Pannonian area.
The Kerkini granitic complex (KGC) intrudes the Serbomacedonian massif KGC comprises the Mûries granite (MUR), the Miriofito granite (MIR), and the Kastanusa (KAS) granodiorite. The main rock-type is two-mica granite. Feldspars are represented by albite andperthitic microcline, biotite is iron-rich and white mica is phengite. Fluorite is also present. The rocks are peraluminous, enriched in total alkalis, depleted in MgO and CaO and have high FeOt/MgO ratios. They are enriched in Zr, Nb, Y, Ga and REE, and have strong negative Eu anomaly. They plot in the Atype granite fields of various discriminant diagrams and their chemistry suggests a WPG tectonic environment. Sr initial ratio ranges from 0.7107 to 0.7182. The most probable genetic model is fluid-absent melting of a biotite-rich tonalitic crustal source at 950 -975 C and at considerable depths. Rb-Sr white mica ages and SHRIMP U-Pb zircon ages yielded 246±3 Ma and 247±2Ma, respectively, interpreted as the crystallization age of the KGC. K-Ar ages of 130±3 and 131 ±3 Ma (biotite) and 133±3 Ma (white mica) can be interpreted by a metamorphic/fluid event at about 133 Ma. Rb-Sr white mica dates at 152±2 Ma probably resulted by incomplete resetting of the Rb-Sr isotopie system and yielded "mixing ages" between crystallization (ca. 247 Ma) possibly related to a Permian - Triassic rift event and metamorphic/fluid event (ca. 133 Ma).
Electrifying transportation is a promising approach to alleviate climate change issues arising from increased emissions. This study examines a system for the production of hydrogen using renewable energy sources as well as its use in buses. The electricity requirements for the production of hydrogen through the electrolysis of water, are covered by renewable energy sources. Fuel cells are being used to utilize hydrogen to power the bus. Exergy analysis for the system is carried out. Based on a steady-state model of the processes, exergy efficiencies are calculated for all subsystems. The subsystems with the highest proportion of irreversibility are identified and compared. It is shown that PV panel has exergetic efficiency of 12.74%, wind turbine of 45%, electrolysis of 67%, and fuel cells of 40%.
