A. Tsirambides

Technical properties of compounded kaolin sample from Griva (Macedonia, Greece)

Abstract The purpose of this paper is to establish the possible industrial applications of Griva kaolin. This kaolin comes from the alteration of gabbroic rocks from the Griva area, Macedonia, Greece. Mineralogically, the kaolin is composed mainly of kaolinite associated with vermiculite and plagioclases, and traces of quartz, amphiboles, halloysite and smectites. The kaolin grain-size analysis shows that the kaolin is mostly finer than

Zeolitic alteration of Eocene volcaniclastic sediments at Metaxades, Thrace, Greece

Abstract The conditions of alteration of the upper Eocene zeolite-bearing volcaniclastic sediments at Metaxades, Thrace, Greece, were examined using a variety of petrographic and mineralogical techniques. A fine silt- to clay-size matrix, containing abundant altered glass shards, predominates. The primary minerals include quartz, K-feldspar, plagioclase, micas (especially biotite) and some opaque minerals. The diagenetic phases, clinoptilolite, smectite and cristobalite, occur as microcrystalline aggregates within the matrix or as replacements of glass shards. The abundances of cristobalite and clinoptilolite are related chiefly to the original composition of the rocks. The abundance of cristobalite increases and that of clinoptilolite + smectite decreases as the abundance of the matrix increases. The formation of clinoptilolite and cristobalite took place either at near-surface temperatures or at slightly elevated temperatures (lower than 70°C). The smectite content of the altered volcaniclastics decreases with increasing depth in the 15 m thick exposed section. No other systematic variation in mineral assemblages with depth was observed. However, the ratio clinoptilolite/smectite increases systematically with depth suggesting to us that smectite may have formed subsequent to the formation of clinoptilolite and as an alteration product of clinoptilolite. The initial composition of the volcanic material and to a less extent the interstitial fluids, greatly affected the diagenetic mineral assemblages of the final alteration products.

Thermal characterization of carbonate rocks, Kozani area, North-western Macedonia, Greece

Representative carbonate rock samples collected from the broader area of Kozani (NW Macedonia, Greece) are examined. The participation of constituents in the formations was determined combining three different methods of analysis, atomic absorption spectroscopy (AAS), X-ray diffraction analysis (XRD) and thermogravimetry (TG). The three methods are used in a complimentary way in order to specify the exact composition of the samples. Although the question about the composition can be answered by AAS, the percentage of the included calcite and dolomite can be determined with accuracy, only through TG analysis, under the appropriate conditions, regarding the gas carrier. The results of the analysis lead to a more complete view of the geological conditions that predominated in the studied area.

Metallic mineral resources of Greece

Today Greece produces and exports raw bauxite and alumina, concentrates of galena and sphalerite and ferronickel. The indicated reserves of bauxite, located in the Mt Helikon-Mt Parnassus-Mt Giona-Mt Iti zone, are estimated at approximately 100 mt and those of aluminum 2.5 mt. The probable and indicated reserves of lead and zinc from Chalkidiki are approximately 3.125 mt. The total production of concentrates of galena and sphalerite is approximately 220,000 tpa. The proven reserves of nickel are approximately 1.392 mt and the production of ferronickel is approximately 18,500 tpa. Production of copper, silver and gold is pending in 2015. The probable and indicated reserves of copper from Skouries Chalkidiki are approximately 1.943 mt. In the Prefecture Units of Chalkidiki and Evros the probable and indicated reserves of gold are approximately 19.37 million ounces and those of silver 131.6 million ounces. Chromium, manganese and molybdenum present good prospects of exploitation. Calculated at current prices, the total gross value of the probable and indicated reserves of the metallic minerals of Greece is €79.4 billion.

An X-ray, EPMA, and oxygen isotope study of vermiculitized micas in the ultramafic rocks at Askos, Macedonia, Greece

Abstract Extensive metasomatic zones of vermiculite-, tremolite-, chlorite-, and talc-rich rocks have been developed at the contacts of serpentinized ultramafic bodies and surrounding two-mica gneisses in the Askos area, Macedonia, Greece. These zones are probably related to the intrusion of acid magmatic bodies in the area. X-ray and EPMA studies confirmed the formation of vermiculite through a layer-by-layer transformation of original micas. In decreasing abundance, the following mixed-layer and discrete phases were identified: biotite/trioctahedral vermiculite (hydrobiotite), biotite/smectite, trioctahedral chlorite/trioctahedral vermiculite (corrensite), vermiculite/smectite and discrete biotite, vermiculite, chlorite and talc. The 2–20 μm fraction of the vermiculitic samples consists mostly of biotite/vermiculite (>40%) with the biotite percentage dominating in the mixed phase. Lower abundances (20–40%) of biotite/smectite and chlorite/vermiculite occur in both finer fractions (2–20 and

The role of organic matter of carbonate rocks in the reactivity of the produced quicklime

The gray and white crystalline limestones from Agios Panteleimonas Florina have almost the same mineralogical composition. They are mainly composed of calcite (96%), while the percentage of the contained organic matter is 0.8% in the gray and 0.09% in the white crystalline limestone. After heating both crystalline limestones at 500°C no serious change was observed concerning their mineralogical composition. However, the velocity of P waves and the porosity in the gray limestone are changed significantly while this trend is not noticed in the white limestone. These changes are mainly attributed to the burning of organic matter, which is contained with greater percentage in the gray crystalline limestone. At 1000°C both crystalline limestones are completely calcined. The dissociation of calcite and dolomite increases significantly the porosity of the produced quicklime. The quicklime from gray crystalline limestone presents higher porosity value (by 5.2 percentage units) and it is more reactive (by 4.9 percentage units) in comparison with the quicklime from white crystalline limestone. This difference in the reactivity is mainly attributed to the difference in the percentage of organic matter contained in the two crystalline limestones.RésuméLes calcaires cristallins, gris et blancs, de Agios Panteleimonas Florinas, ont à peu près la même composition minéralogique. Ils sont composés essentiellement de calcite (96%), tandis que le pourcentage de la matière organique contenue est de 0,8% dans le gris et 0,09% dans le calcaire cristallin blanc. Le chauffage de ces deux calcaires cristallins à 500°C n’apporte aucun sérieux changement concernant leur composition minéralogique. Toutefois, la vitesse des ondes P et la porosité du calcaire gris ont considérablement changé, tandis que cette tendance n’est pas notée dans le calcaire blanc. Ces changements sont attribués à la combustion de la matière organique, dont le pourcentage est plus élevé dans le calcaire cristallin gris. À 1000°C les deux calcaires cristallins sont complètement calcinés. La destruction de la calcite et de la dolomite augmente considérablement la porosité de l’asbeste produit. L’asbeste produit par le calcaire cristallin gris présente une valeur de porosité supérieure de 5,2% et il est plus réactif (de 4,9%) en comparaison avec l’asbeste produit par le calcaire cristallin blanc. Cette différence de réactivité est essentiellement attribuée à la différence du pourcentage de matière organique contenue dans les deux calcaires cristallins.

Kaolin weathering crusts on gabbroic rocks at Griva, Macedonia, Greece

Abstract The hydrothermal and weathering alteration products of the gabbroic rocks at Griva, Macedonia, Greece, are examined using petrographic, mineralogical and chemical data. The kaolin crusts have a thickness of 1 to 8 m and extend over an area of about 5 km 2 . Many gabbro-pegmatitic veins crosscut the semi-friable kaolins. The crusts have not been intensively washed and thus the primary minerals exist within the weathered profile in significant amounts. Essential constituents are plagioclase, actinolite, clinopyroxene, clinozoisite, dolomite, kaolinite, corrensite and pyrophyllite, with varying proportions in the different particle size fractions. The 18 O values. According to the classification of Konta the kaolins studied are of the low grade type and probably only suitable for the ceramic industry.

Modern sands derived from the Vertiskos Unit of the Serbomacedonian Massif (N. Greece): a preliminary study on the weathering of the Unit

Modern sand samples were collected from the Vertiskos Unit of the Serbomacedonian Massif, northern Greece, and were examined for their texture and mineralogical composition. They were collected from active channels and torrents. The textural study demonstrated that these modern sands are moderately to very-poorly sorted, often polymodal in grain size distribution, texturally and mineralogically immature to submature, and consist of coarse-grained gravelly sands to slightly-gravelly muddy sands. The dominant composition is quartzofeldspathic. All samples contain detrital minerals of metamorphic origin, mainly amphibole and garnet, in addition to minor amounts of pyroxene and detrital calcite. These sediments were deposited rapidly and close to their source, the metamorphic basement of the Vertiskos Unit. The mineral constituents of the samples indicate that the Vertiskos Unit is undergoing rapid physical weathering due to the temperate and seasonal climate. The results of this study suggest that these modern sands constitute one sedimentary petrologic province comprised of primarily of amphibole-garnet.

Purification of wastewater from Sindos industrial area of Thessaloniki (N. Greece) using Hellenic Natural Zeolite

The treatment of wastewater from Sindos industrial area of Thessaloniki, Greece (initial pH 7.8) with the Hellenic Natural Zeolite (HENAZE), resulted to clear water of pH 7.3, free of odours and improved by 93% in the colour, 69% in the chemical oxygen demand (COD), >97% in the P2O5 removal, 54% in the NO3 removal and 77% in the Cr removal. The sorption and fixation of the different species from the wastewater by the micro- meso- and macroporous of HENAZE can be attributed to absorption (mainly ion exchange), adsorption and surface precipitation processes. Important role in these processes play the surface Broensted acidic and Lewis basic sites of the HEU-type zeolite. In addition the HENAZE treatment gave odourless and cohesive zeosludge, suitable for safe deposition since the fixation of dangerous components into the micro- meso- and macroporous of HENAZE, prevents the seepage of them by the rain water, protecting thus the quality of surface and underground waters. The used HENAZE sample, comes from Ntrista stream area of Petrota village (Evros Prefecture, Northeastern Greece) and contains 88 wt.% HEU-type zeolite, 4 wt.% mica + clays (92 wt.% microporous minerals), 5 wt.% feldspars and 3 wt.% SiO2-phases (quartz + cristobalite). The mineralogical composition and the physico-chemical properties, make the HENAZE suitable material for numerous environmental, industrial, agricultural and aquacultural applications.

Using detrital garnets to determine provenance: a case study from the Vertiskos Unit (Serbomacedonian Massif, N. Greece)

Garnet single crystals of several millimeters in diameter were collected from the uppermost horizon of a soil profile developing immediately on the gneissic rocks of the Vertiskos Unit of the Serbomacedonian Massif in northern Greece. The garnets were analyzed for major elements by EDS analyzer mounted on a scanning electron microscope, and the obtained data were utilized to determine their source rocks. Bivariate diagrams, spider diagrams as well as statistical analysis were used in order to correlate and compare the garnet composition of the basement rocks of the Vertiskos Unit with the existing reference data. This case study demonstrates the difficulty in assigning a source rock to sediment, using only the chemical compositional of detrital garnet. Direct linking of the detrital garnets and the outcropping rocks is not always possible despite well documented outcrop lithologies. This is largely due to a complex metamorphic evolution that leads to overlapping compositions between garnets originating from different lithologies that have undergone similar metamorphic processes and alteration effects.