Tertiary magmatism within the Republic of Macedonia: a review

Widespread Tertiary magmatism of both orogenic and within-plate signatures developed within the Macedonian part of the Dinarides. Orogenic magmatites (predominantly volcanic rocks) are present in 5 areas (from east to west): Osogovo-Besna Kobila, Kratovo-Zletovo, Bucim-Borov Dol, Dojran and Kozuf. The age of the igneous rocks decreases in the same direction: from Priabonian-Early Oligocene at Os ogovo-Besna Kobila area, Early Oligocene-Miocene in Kratovo-Zletovo and Bucim-Borov Dol to Late Miocene-Late Pliocene in Kozuf. The Osogovo-Besna Kobila area contains only acid volcanics (trachydacites to dacites), occurring mainly as subvolcanic to hypabyssal bodies. They have collision-related chemical characteristics. Latites and andesites to dacites predominate in the Kratovo-Zletovo area, but a monzonite pluton is also be found . Only the shoshonite series (from latites to trachy­ rhyolites) is present in Bucim-Borov Dol, and trachytes in Dojran area. The Kozuf area, which consists of two series; (I) shoshonitic (high-Mg shoshonites, latites and trachydacites) and (2) andesitic series (Iow-K andesites and high-Fe rhyo­lites), seems to be the most complex volcanic field. Magmatites in the last three areas have island arc signatures. The within-plate volcanics rocks are high-K to ultra-K mafic igneous rocks (phonotephrites) accompanied by some absarokite, shoshonite to Iatite .occurrences. Their age is Upper Miocene-Pliocene. These rocks are grouped in 4 areas: Kumanovo, Skopje-SLNikole, Stip and Demir Kapija. The high Mg' and the high Cr-Ni contents of the phonotephrites, together with Fo-rich olivine phenocrysts suggest their asthenospheric origin

Kinetics of perlite glasses degassing: TG and DSC analysis

Kinetics of dehydration is one of the important characteristics of natural water-bearing glasses. This study deals with the simultaneous TGA/DSC of perlites. The dehydration profiling of natural perlite samples from Eastern Rhodopes (Bulgaria) and a pitchstone from the Eastern Transbaikal region (Russia) has been obtained by the use of a thermal balance. Initial water content in samples varied between 4.0 to 6.5 wt% H₂O. In pitchstone TG and DTG signals indicate two degassing maxima at temperatures of 220 and 290 °C. The peaks in the DTG signal mimic those in DSC signal. Perlitic water is driven out smoothly under heating over a wide ränge of temperatures from 140 to 700°C up to the glass transition temperature (Tg). The glass transition temperature has been determined independently from viscosity measurement using a micropenetration method. In slowly cooled perlites DTG and DSC Signals have one distinct peak which extends from 140 up to 800 to 850 °C. In fast cooled perlites DTG and DSC signals often exhibit two distinct peaks at around 200 to 450 and 600 to 700 °C. The temperature ränge of DTG and DSC peaks is wider than in slowly cooled perlites. The enthalpy effect of perlite glass dehydration at 200 to 300 °C has the enthalpy value of 55 to 75 kJ/mol, which is much larger than the enthalpy value (30 to 25 kJ/mol) of water evaporation at these temperatures. The additional thermal effect of periite dehydration may be associated with the water desorption reaction and water vapour expansion in microcracks

Petrological and geochemical characterization of Ge-bearing coals from the eastern Rhodopes, Bulgaria

The coals from Pchelarovo and Vulce Pole are perhydrogenated coals showing high sulphur content (3.2 - 6.2 wt%) and significant Ga and Ge contents (0 - 480 ppm) in organic matter (OM). The coals from Medenbuk could be perhydrogenated coals modified by weathering processes. They show low sulphur content (1.5 wt%), high homogeneous Ge contents in OM (~2500 ppm) and an unusual enrichment in Ge (up to 0.8 wt%) and V (2.8 wt%) in weathered zones of framboïdal pyrite. Sulphur isotopic study of pyrite and organic sulphur provides evidence of bacterial reduction of dominantly seawater sulphates. However taking account the geological context of the three basins, the introduction of volcanic fluids in the basins of Pchelarovo and Vulce Pole during their forma-tion cannot be excluded

Orogenic Tertiary magmatism on the Macedonian Dinarides: a Review

Widespread Tertiary magmatism of orogenic signature developed on the Macedonian part of the Dinarides, essentially in the Serbo-Macedonian massif and in the Vardar zone (KARAMATA et al., 1992). Orogenic magmatic rocks (predominantly volcanic) are presented in 5 areas (from east to west): the Osogovo-Besna Kobila, Kratovo-Zletovo, BuCim-Borov Dol, Dojran and Kozuf

Tertiary pluton Pantelej in the Vardar zone, Republic of Macedonia

The intrusive magmatism of Tertiary age call be seen neM the village of Pantelej in the Vardar zone, the Republic of Macedonia. This intrusive magmatism is present as a relatively smaller pluton built up of quartzmonzonites and monzonites. The chemical cOll1positioll of the rocks is very similar to the composition of the volcanic rocks that occur in the wider vicinity of the Kratovo - Zletovll volcanic area. The paper also presents data related to the contents of strOlltiull1 isotopes

Mineralogy of the pliocene trachyte and its carbonatitic minette inclusions in Ostrvica, FYR of Macedonia

The trachyte at Ostrvica hill (age 3.21±0.10 Ма) in Vardar zone is the most evolved volcan- ics of the ultrapotassic Pliocene-Quaternary series in F.Y.R. of Macedonia. It is aphyric, with clinopy- roxene and phlogopite microphenocrysts within a sanidine-anorthoclase groundmass. It contains inclu- sions of carbonatitic minette ranging in size from several mm to 6–7 cm. They are light coloured por- phyric rocks, rich in vacuoles, composed of phlogopite and completely altered olivine(?) phenocrysts amongst acicular clinopyroxenes within a feldspar–calcite groundmass with abundant Fe-oxides and acicular apatite microlites. The inclusions are rimmed by a mm thick mixing zone composed of the same minerals but with intermediate composition between that of minette and trachyte. The clinopyroxenes are mainly diopside-augite with low Ti and Al content (with 6Al only in the minette). Positive correla- tions are observed between Na and Fe3+, Al and Ti, and negative one – between Al and Si. In the inclu- sions phlogopites the negative correlation between Mg# and 4Al is found. The feldspars in the trachyte and minette inclusions are Ca-sanidine to Ca-anorthoclase, in the mixing zone – sanidine only. In the in- clusions two plagioclase generations (An41 and An25) exist. The estimated crystallization temperature of the minette clinopyroxenes is 1280–1180С, of plagioclase (An41) – 1130С and in the hosting trachyte – 1080С, at the pressures 6.9 and 7.7 kbar, respectively. The temperature of the feldspars crystalliza- tion (K-Na-feldspars and Pl24) in the minette groundmass is 809–878C. By analogy with other ultrapo- tassic volcanics from F.Y.R Macedonia it is suggested, that the discussed volcanics originated from phlogopite-bearing metasomatised mantle

Eruptive history and source area of 2-nd Rupelian acid phase volcaniclastics from northern parts of Dzhebel depression (Eastern Rhodopes, South Bulgaria) as inferred from the pyroclastic stratigraphy and petrography

status: publishe

Neogene ultrapotassic-potassic volcanic association in the Vardar zone (Macedonia)

The studied volcanic rocks in Kumanovo, Sveti Nikole and Demir kapija areas are of Late Miocene - Pilocene age and potassic to ultrapotassic character (Romanian type). They have been clasified as phonotephrites, shoeshoites and latites with high Mg# (> 70) and high Ni and Cr contents indicative of their primitive nature. The volcanics contain phenocrists of Fo - rich olivine, diopside to augite, phlogopite to Ba - and Ti - rich biotete (close to a kinoshitalite) in a groundmass consisting of microlites of the same minerals + leucite. Ti - magnetite +-ilmenite enclosed by Na - sanidine and/or anorthose. The rocks are significantly enriched in LILE and show negative Ta, Nb, Ti an positive Pb anomalies. The trace elements distribution for ultrapotassic varietie

Mineralogy of the Plio-Pleistocene potassic and ultrapotassic volcanic rocks from the Republic of Macedonia

Ultra- to high potassic volcanic rocks of Plio-Pleistocene age (3.24-1.47 Ma) crop out in the Vardar zone. On the basis of chemical composition, they are classified as phonotephrites to ultrapotassic shoshonites and latites, including also high-Mg latites. They contain pheno- and microphenocrysts of olivine, clinopyroxene, phlogopite, ± leucite. The groundmass consists of poikilitic Ba-Na sanidine and Ba-Ti phlogopite, ± Sr-rich oligoclase (up to 3 wt.% SrO), anorthoclase and Mg-bearing calcite, all enclosing microlites of clinopyroxene, phlogopite, Ti-magnetite, ± leucite. The olivine phenocrysts are zoned, forsterite-rich (up to Fo 93), and display a positive correlation between Fo component and NiO and negative one between the same component and MnO. The clinopyroxenes are diopside-augites, and some of them are rich in Al (up to 5.4 wt.% Al2O3), which correlates positively with Ti. On the other hand, Ti correlates negatively with Mg# and Si. The micas are essentially phlogopites rich in Ti (up to 12 wt.% TiO2). In some localities they are also highly enriched in Ba (up to 8.3 wt.% BaO) approaching to the Ti-kinoshitalite composition. Ba in micas correlates positively with Ti and Al, but negatively with K, Mg# as well as with Si. A positive correlation between Ba and Sr and negative one between Ba and Si/Al ratio is observed in both sanidine and plagioclase. The leucite microphenocrysts are sometimes replaced by Na-sanidine, zeolites (laumontite, phillipsite, etc.) and clays or by nepheline and amorphous nephelinic masses. The obtained mineralogical features of the Macedonian ultrapotassic rocks assign them to the Roman Province Type rocks