Th e Stravaj ophiolite compex, part of the western Mirdita ophiolite belt in Albania, is located ... more Th e Stravaj ophiolite compex, part of the western Mirdita ophiolite belt in Albania, is located east of the Shpati massif, and west of the Shebenik massif. Th e Stravaj ophiolite sequence itself consist of MOR-related and subductionrelated volcanic rocks (Hoeck et al. 2007) formed by pillow lavas and various dykes. Th e deeper units are formed by gabbros and plagioclase-bearing peridotites. Th e pillow lavas are intersected by basaltic dykes with a rather primitive composition. Th e studied basaltic dyke contains former relics of olivine, fresh spinel and clinopyroxene phenocrysts in a glassy groundmass. Th e silicate phases are strongly altered. Th e spinels appear as fresh, opaque grains preserved in totally altered olivine phenocrysts. Th e spinels host negative crystal shaped, multiphase silicate melt inclusions. Th e inclusions consist commonly of clinopyroxene daughter minerals, glass and rare sulphide blebs. A series of heating experiments were conducted, using the furnace technique to homogenize the silicate melt, in order to obtain homogenized silicate melt inclusions for major and trace element composition analysis and to determine their homogenization temperatures. Th erefore, samples were heated to and quenched from 1200±20°C to 1240°C. Th e melt inclusions homogenized between 1220-1240±20°C. Th e major element composition of the homogenized melt inclusions is 48.3-51.2 wt% SiO 2 , 5.4-6.7 wt% FeO, 9.9-12.6 wt% MgO, 14.5-17.3 wt% Al 2 O 3 , 1.9-2.4 wt% Na 2 O and 12.1-13.0 wt% CaO. Th is result is highly comparable with the host mafi c rock composition. Th e trace element composition of the homogenized silicate melt shows characteristic LREE-depleted patterns (La: 0.24-0.35 ppm), while the MREE and HREE patterns are generally fl at: average PM-normalized La/Lu is 0.094. Th e average contents of compatible trace elements such as Cr, Ni, V, Co are up to 621 ppm, 825 ppm, 235 ppm and 80 ppm, respectively. Based on the major composition, trace element characteristics and the calculated oxygen fugacity, the studied silicate melt inclusions show strong similarities to MOR-related volcanic rocks found commonly in the Stravaj Massif. Th ese chromite-bearing basalt dykes defi ne extreme primitive MORB related melts in the upper part of the pillow lava section.
Nowadays much more attention is being paid to the influence of mankind on our environment than pr... more Nowadays much more attention is being paid to the influence of mankind on our environment than previously. The expansion of urban conglomerations and the developing industry has resulted in an increased amount of aggressive pollutants [1]; therefore in the 21st century one of the major roles of society is to conserve its historical and cultural heritage. Pollutants from transport, heating and industry deposit on the built environment, causing its deterioration. Deterioration of natural building materials, like stone (e.g. freshwater and coarse limestone), is subject of numerous studies [e.g. 2], however few studies are designed to research the effect of air pollutants (e.g. sulfur dioxide, nitrogen oxides, soot, dust) on man-made silicate-based materials (ceramic, glaze, glass etc.). In Budapest there are many examples of historic buildings covered with glazed ceramics (e.g. the Museum of Applied Arts, Parliament, the Geological Institute and Matthias Church). It is widely accepted ...
Eleven representative xenoliths from the Minusinsk Region, southern Russia were studied in order ... more Eleven representative xenoliths from the Minusinsk Region, southern Russia were studied in order to highlight the characteristic features of the subcontinental lithospheric mantle beneath the region. Type-I xenoliths show that the lithosphere underwent various degree of depletion overprinted by enrichment processes leading to LREE-enriched pyroxenes. Estimated equilibrium temperature for the xenoliths is in the range of 960-1050 ºC. Type-II xenoliths are the result of crystallization from a possibly basaltic melt close to the crust-mantle boundary. Three xenoliths in the Type-I series show evidence of incipient melting such as spongy rims of pyroxenes and interstitial glass. The spongy rims of clinopyroxene consist of clinopyroxene and glass with modal proportion of approximately 82 and 18 %, respectively. Orthopyroxene rim contains olivine (65 %) and glass (35 %) with subordinate amounts of clinopyroxene (< 5 %). Glass within the spongy rims exhibits a clear geochemical affinity to interstitial glass as both have similarly high Al 2 O 3 , SiO 2 and alkali contents. The interstitial glass and the spongy rims (minerals + glass) display light rare earth (LRE) element and large ion lithophile (LIL) element enriched character. This indicates that incipient melting of pyroxenes occurred in an open system and was likely triggered by the influx of a Na alkali silicate melt/fluid. The interstitial glass represents the residual melt after interaction with the pyroxenes. The formation of this Na-rich silicate melt may represent an earlier stage of the mantle magmatic event that produced the host basalt.
The main aim of this work is to study crustal granulite xenoliths from Beistein (Styrian Basin, A... more The main aim of this work is to study crustal granulite xenoliths from Beistein (Styrian Basin, Austria). Styrian-basin is situated at the westernmost part the Pannonian-basin-system. We collected 17 felsic granulite xenoliths, from basaltic pyroclastics near Beistein. We made petrography, geothermo-barometry and fluid inclusion studies to find out their evolution and fluid content and to make a comparison with other
Detailed major and trace element analysis and fabric analysis has been used to study special peri... more Detailed major and trace element analysis and fabric analysis has been used to study special peridotite xenoliths showing unusual tabular equigranular (flattened) texture (Fig. 1) which were found in Plio-Pleistocene alkali basalts from the Bakony—Balaton Highland Volcanic Field (Hungary). The peridotites are relatively clinopyroxene poor (~ 5 vol%) and reflect depleted major and variable trace element compositions. Crystallographic preferred orientation patterns of olivine and orthopyroxene crystal axes were analyzed with universal stage. In case of olivine, the activation of multiple slip systems: (010)[100] and (100)[001] is indicated, whereas the deformation micromechanisms of orthopyroxenes are suggested to be complex. We suggest that the observed orthopyroxene orientation patterns are the result of multistage (at least two) deformation events, which are supposed also to be responsible for unusual orientation patterns of olivines. The orientations in the stress fields of the subalternate deformations were significantly different. These results corraborate well with geophysical models proposing that the Pannonian Basin was formed under varying stress fields. The flattened equigranular xenoliths are suggested to represent a structural domain within the subcontinental lithospheric mantle beneath the volcanic field with predictable seismic characteristics. The occurrence of flattened domains in the upper mantle may considerably influence the percolation and residence time of the mantle melts and fluids.
Due to the increasing number of presentations and publications dealing with fluid and melt inclus... more Due to the increasing number of presentations and publications dealing with fluid and melt inclusions, it became apparent that it would be worth compiling auniform, Hungárián terminology. This study is based on the glossary compiled by L. W DIAMOND in 2003. Összefoglalás A fluidum-és olvadékzárványokkal foglalkozó előadások, dolgozatok és publikációk számának növekedésével felmerült az igény az egységes, magyar nyelvű terminológia alapvető fogalmainak rögzítésére. A szótár alapját L. W DIAMOND 2003-ban publikált szószedete képezi. Bevezető 2005-ben, az olaszországi Sienában megrendezett XVIII. European Current Research on Fluid and Melt Inclusions (ECROFI XVIII) konferencián a résztvevők számát tekintve a rendező olaszok után a magyaroké volt a legnépesebb " delegá ció". A konferencián egyértelműen kiderült, hogy a magyar szakemberek sikeresen alkalmazzák a fluidum-és olvadékzárványok vizsgálatát különböző földtani kérdé sek megválaszolására is. Amint azt a konferencián ...
Geological Society, London, Special Publications, 2015
We have investigated two buildings covered with Zsolnay glazed architectural ceramics in Budapest... more We have investigated two buildings covered with Zsolnay glazed architectural ceramics in Budapest (Hungary), one located in the densely built-up area of the city centre with a high traffic rate and one in a city quarter with moderate traffic and more open space. A black crust layer, containing a large amount of artificial particulate matter with different size and chemical composition, was observed on the ceramic material of both buildings, whereas weathered glaze was detected only on the ceramics of the building situated in the city centre. In this paper, our goal is to reveal the role of the particulate matter in the degradation of architectural ceramics. For this reason the attic dust and settled dust from the roofs of the studied buildings were collected. In the attic dust, besides the natural particles of geological origin, three types of artificial particles typically with spherical shape (spherules) were also distinguished: aluminosilicate (two subtypes), carbonaceous, and ir...
ABSTRACT Orthopyroxene lattice preferred orientation (LPO) in spinel lherzolite xenoliths from Sz... more ABSTRACT Orthopyroxene lattice preferred orientation (LPO) in spinel lherzolite xenoliths from Szentbekkella (Bakony-Balaton Highland, W-Hungary, Central Pannonian Basin), with special tabular textures was studied, using universal stage measurements. LPO patterns of orthopyroxene show a (001) maximum parallel to the lineation in the foliation plain and another maximum perpendicular to the lineation and the foliation. The pattern of the (010) plains also displays a double maximum similar to that of (001). The pattern of the (100) plains displays a single maximum perpendicular to the lineation in the foliation plain. Only very few orthopyroxenes display the ``normal&#39;&#39; LPO pattern: 001 parallel to the lineation and the foliation and 010 perpendicular to both. Olivine LPO&#39;s are normal, (100) plains are in the foliation parallel to the lineation, whereas (010) is perpendicular to the lineation and foliation, both showing single maximums. The orthopyroxenes are more resistant to recrystallization than olivines and may preserve earlier deformation states of the mantle. We suggest that observed orthopyroxene patterns are due to a deformation predating the deformation that recrystallized the olivines in the mantle. The orientations of the stress fields of the two deformations were significantly different, almost perpendicular. These results correspond to early geophysical modeling, suggesting that the Pannonian Basin was formed by a two-stage deformation process and may also provide information on the genesis of these special textural types.
ABSTRACT There are several localities in the Carpathian-Pannonian region where Plio-Pleistocene a... more ABSTRACT There are several localities in the Carpathian-Pannonian region where Plio-Pleistocene alkali basalts lavas and pyroclasts on the surface contain ultramafic xenoliths originating from the upper mantle. One of these occurrences is the Nógrád-Gömör Volcanic Field which is located in the northern part of the Pannonian Basin. Xenoliths from this area have undergone to various petrologic and geochemical studies in the past few decades, however, there is a lack of examinations focusing on crystallographic orientation. A method based on measurements with electron backscatter diffraction (EBSD) can provide insight into crystal preferred orientations of olivine and orthopyroxene - the major rock forming minerals of the mantle xenoliths. 14 lherzolites from 7 quarries of the Nógrád-Gömör Volcanic Field with previously studied petrography and mineral major element chemistry were selected to be measured with EBSD, for the purpose of determining olivine and orthopyroxene crystal preferred orientations, which are usually the result of a change in the physical conditions of the upper mantle (p, T, stress, strain, etc.). The distribution of crystallographic axes in olivines can be divided into three distinctive groups based on the alignment and directions of the a, b and c axes. These distribution groups are more or less related to the macroscopic texture and show a correlation with olivine J-indexes, which indicate the strength of the xenolith fabric. There is also a link between crystallographic orientations and calculated equilibrium temperatures. Our results show that samples from the southern part of the Nógrád-Gömör Volcanic Field (Bárna-Nagykő) display overally lower equilibration temperatures than those collected in the central part (Babi Hill and Medves Plateau). This difference in temperature, and hence in the estimated depth of origin may be responsible for the observed distribution of olivine crystal axes. Nevertheless, various crystallographic orientations suggest that there may be more deformation mechanisms that have activated on distinct levels of the mantle beneath the NGVF.
ABSTRACT We have reconstructed the compositional evolution of the silicate and carbonate melt, an... more ABSTRACT We have reconstructed the compositional evolution of the silicate and carbonate melt, and various crystalline phases in the subvolcanic reservoir of Kerimasi Volcano in the East African Rift. Trace element concentrations of silicate and carbonate melt inclusions trapped in nepheline, apatite and magnetite from plutonic afrikandite (clinopyroxene-nepheline-perovskite-magnetite-melilite rock) and calciocarbonatite (calcite-apatite-magnetite-perovskite-monticellite-phlogopite rock) show that liquid immiscibility occurred during the generation of carbonatite magmas from a CO2-rich melilite-nephelinite magma formed at relatively high temperatures (1,100 °C). This carbonatite magma is notably more calcic and less alkaline than that occurring at Oldoinyo Lengai. The CaO-rich (32-41 wt%) nature and alkali-“poor” (at least 7-10 wt% Na2O + K2O) nature of these high-temperature (&gt;1,000 °C) carbonate melts result from strong partitioning of Ca (relative to Mg, Fe and Mn) in the immiscible carbonate and the CaO-rich nature (12-17 wt%) of its silicate parent (e.g., melilite-nephelinite). Evolution of the Kerimasi carbonate magma can result in the formation of natrocarbonatite melts with similar composition to those of Oldoinyo Lengai, but with pronounced depletion in REE and HFSE elements. We suggest that this compositional difference results from the different initial parental magmas, e.g., melilite-nephelinite at Kerimasi and a nephelinite at Oldoinyo Lengai. The difference in parental magma composition led to a significant difference in the fractionating mineral phase assemblage and the element partitioning systematics upon silicate-carbonate melt immiscibility. LA-ICP-MS analysis of coeval silicate and carbonate melt inclusions provides an opportunity to infer carbonate melt/silicate melt partition coefficients for a wide range of elements. These data show that Li, Na, Pb, Ca, Sr, Ba, B, all REE (except Sc), U, V, Nb, Ta, P, Mo, W and S are partitioned into the carbonate melt, whereas Mg, Mn, Fe, Co, Cu, Zn, Al, Sc, Ti, Hf and Zr are partitioned into the silicate melt. Potassium and Rb show no preferential partitioning. Kerimasi melt inclusions show that the immiscible calcic carbonate melt is strongly enriched in Sr, Ba, Pb, LREE, P, W, Mo and S relative to other trace elements. Comparison of our data with experimental results indicates that preferential partitioning of oxidized sulfur (as SO4 2−), Ca and P (as PO4 3−) into the carbonate melt may promote the partitioning of Nb, Ta, Pb and all REE, excluding Sc, into this phase. Therefore, it is suggested that P and S enrichment in calcic carbonate magmas promotes the genesis of REE-rich carbonatites by liquid immiscibility. Our study shows that changes in the partition coefficients of elements between minerals and the coexisting melts along the liquid line of descent are rather significant at Kerimasi. This is why, in addition to the REE, Nb, Ta and Zr are also enriched in Kerimasi calciocarbonatites. We consider significant amounts of apatite and perovskite precipitated from melilite-nephelinite-derived carbonate melt as igneous minerals can have high LREE, Nb and Zr contents relative to other carbonatite minerals.
Silicate melt inclusions are frequent in the phenocryst phases (quartz, plagioclase, orthopyroxen... more Silicate melt inclusions are frequent in the phenocryst phases (quartz, plagioclase, orthopyroxene, ilmenite and accessory minerals) of the Miocene silicic pyroclastic rocks of the Bükkalja Volcanic Field, Northern Hungary. These melt inclusions were trapped at different stages of magma evolution; therefore, they provide important information on the petrogenetic processes. The melt inclusions in the Bükkalja pyroclastic rocks show various textures such as (1) wholly enclosed type; (2) hourglass inclusions and (3) reentrant or embayment glass. Among the wholly enclosed type melt inclusions further textural subgroups can be distinguished based on their shape: negative crystal, rounded, elongated and irregular shaped. These various textures reflect differences in the time of entrapment prior to eruption and in the post-entrapment condition in the magma chamber. The largest textural variation was found in the quartz-hosted melt inclusions. However, the major element compositions of these melt inclusions do not differ from one another in the same unit. In general, compositions of the melt inclusions are similar to the chemistry of the glass shards. Comparing the composition of the quartz-hosted melt inclusions from three main ignimbrite units (Lower, Middle and Harsány Ignimbrite Units), slight differences have been recognized, suggesting distinct erupted host magmas. Melt inclusions from the andesitic lithic clast of the Lower Ignimbrite Unit could represent heterogeneous interstitial melt in the crystal mush zone at the magma chamber wall. The largest geochemical variation was found in the melt inclusion of the Middle Ignimbrite Unit, even in single samples. This compositional variation overlaps that of the rhyolitic juvenile clasts, but does not match that of the glasses of scoria clasts. We suggest that syn-eruptive magma mixing (mingling) occurred in a compositionally heterogeneous magma chamber of the Middle Ignimbrite Unit.
Segregation of magmatic fluids and their potential in the mobilization of platinum-group elements... more Segregation of magmatic fluids and their potential in the mobilization of platinum-group elements in the South Kawishiwi Intrusion, Duluth Complex, Minnesota-evidence from petrography, apatite geochemistry and coexisting fluid and melt inclusions, Ore Geology Reviews (2013),
We review deformation fabrics in mantle xenoliths from the central part of the Carpathian-Pannoni... more We review deformation fabrics in mantle xenoliths from the central part of the Carpathian-Pannonian Region (CPR) and, in combination with seismic shear wave splitting data, attempt to define patterns of upper mantle anisotropy. Our interpretations from both lines of evidence support a model for east-west oriented asthenospheric flow, decoupled (at least in part) from the overlying lithosphere. Mantle flow fields resulting from Tertiary indentation of Europe by the Adria micro-plate and the resulting Alpine orogen may thus have been an important factor in driving the eastward extrusion of lithospheric blocks in the CPR accompanied by lithospheric extension, rapid 'rollback' of the Carpathian subduction system, and its diachronous collision with the European craton. According to this model, eastward asthenospheric flow would add significantly to the effects of slab rollback and gravitational instability. Thus, opening of the Pannonian Basin, rather than being exclusively driven by 'slab pull' and gravitational instability, could have been resulted, at least in part, from mantle flow associated with the Adria-European collision and ensuing Alpine orogeny. Such models have also been proposed for analogous geodynamic scenarios such as the western and eastern Mediterranean, and western and southwestern Pacific regions, offering a potential generic model for backarc basin opening.
A Late Cretaceous lamprophyre dyke in the Villány Mts (S Hungary), situated in the Tisza unit, co... more A Late Cretaceous lamprophyre dyke in the Villány Mts (S Hungary), situated in the Tisza unit, contains abundant spinel lherzolite xenoliths with porphyroclastic textures. Mineral chemistry suggests a relatively fertile mantle, which experienced only 5–7% melt ...
Th e Stravaj ophiolite compex, part of the western Mirdita ophiolite belt in Albania, is located ... more Th e Stravaj ophiolite compex, part of the western Mirdita ophiolite belt in Albania, is located east of the Shpati massif, and west of the Shebenik massif. Th e Stravaj ophiolite sequence itself consist of MOR-related and subductionrelated volcanic rocks (Hoeck et al. 2007) formed by pillow lavas and various dykes. Th e deeper units are formed by gabbros and plagioclase-bearing peridotites. Th e pillow lavas are intersected by basaltic dykes with a rather primitive composition. Th e studied basaltic dyke contains former relics of olivine, fresh spinel and clinopyroxene phenocrysts in a glassy groundmass. Th e silicate phases are strongly altered. Th e spinels appear as fresh, opaque grains preserved in totally altered olivine phenocrysts. Th e spinels host negative crystal shaped, multiphase silicate melt inclusions. Th e inclusions consist commonly of clinopyroxene daughter minerals, glass and rare sulphide blebs. A series of heating experiments were conducted, using the furnace technique to homogenize the silicate melt, in order to obtain homogenized silicate melt inclusions for major and trace element composition analysis and to determine their homogenization temperatures. Th erefore, samples were heated to and quenched from 1200±20°C to 1240°C. Th e melt inclusions homogenized between 1220-1240±20°C. Th e major element composition of the homogenized melt inclusions is 48.3-51.2 wt% SiO 2 , 5.4-6.7 wt% FeO, 9.9-12.6 wt% MgO, 14.5-17.3 wt% Al 2 O 3 , 1.9-2.4 wt% Na 2 O and 12.1-13.0 wt% CaO. Th is result is highly comparable with the host mafi c rock composition. Th e trace element composition of the homogenized silicate melt shows characteristic LREE-depleted patterns (La: 0.24-0.35 ppm), while the MREE and HREE patterns are generally fl at: average PM-normalized La/Lu is 0.094. Th e average contents of compatible trace elements such as Cr, Ni, V, Co are up to 621 ppm, 825 ppm, 235 ppm and 80 ppm, respectively. Based on the major composition, trace element characteristics and the calculated oxygen fugacity, the studied silicate melt inclusions show strong similarities to MOR-related volcanic rocks found commonly in the Stravaj Massif. Th ese chromite-bearing basalt dykes defi ne extreme primitive MORB related melts in the upper part of the pillow lava section.
Nowadays much more attention is being paid to the influence of mankind on our environment than pr... more Nowadays much more attention is being paid to the influence of mankind on our environment than previously. The expansion of urban conglomerations and the developing industry has resulted in an increased amount of aggressive pollutants [1]; therefore in the 21st century one of the major roles of society is to conserve its historical and cultural heritage. Pollutants from transport, heating and industry deposit on the built environment, causing its deterioration. Deterioration of natural building materials, like stone (e.g. freshwater and coarse limestone), is subject of numerous studies [e.g. 2], however few studies are designed to research the effect of air pollutants (e.g. sulfur dioxide, nitrogen oxides, soot, dust) on man-made silicate-based materials (ceramic, glaze, glass etc.). In Budapest there are many examples of historic buildings covered with glazed ceramics (e.g. the Museum of Applied Arts, Parliament, the Geological Institute and Matthias Church). It is widely accepted ...
Eleven representative xenoliths from the Minusinsk Region, southern Russia were studied in order ... more Eleven representative xenoliths from the Minusinsk Region, southern Russia were studied in order to highlight the characteristic features of the subcontinental lithospheric mantle beneath the region. Type-I xenoliths show that the lithosphere underwent various degree of depletion overprinted by enrichment processes leading to LREE-enriched pyroxenes. Estimated equilibrium temperature for the xenoliths is in the range of 960-1050 ºC. Type-II xenoliths are the result of crystallization from a possibly basaltic melt close to the crust-mantle boundary. Three xenoliths in the Type-I series show evidence of incipient melting such as spongy rims of pyroxenes and interstitial glass. The spongy rims of clinopyroxene consist of clinopyroxene and glass with modal proportion of approximately 82 and 18 %, respectively. Orthopyroxene rim contains olivine (65 %) and glass (35 %) with subordinate amounts of clinopyroxene (< 5 %). Glass within the spongy rims exhibits a clear geochemical affinity to interstitial glass as both have similarly high Al 2 O 3 , SiO 2 and alkali contents. The interstitial glass and the spongy rims (minerals + glass) display light rare earth (LRE) element and large ion lithophile (LIL) element enriched character. This indicates that incipient melting of pyroxenes occurred in an open system and was likely triggered by the influx of a Na alkali silicate melt/fluid. The interstitial glass represents the residual melt after interaction with the pyroxenes. The formation of this Na-rich silicate melt may represent an earlier stage of the mantle magmatic event that produced the host basalt.
The main aim of this work is to study crustal granulite xenoliths from Beistein (Styrian Basin, A... more The main aim of this work is to study crustal granulite xenoliths from Beistein (Styrian Basin, Austria). Styrian-basin is situated at the westernmost part the Pannonian-basin-system. We collected 17 felsic granulite xenoliths, from basaltic pyroclastics near Beistein. We made petrography, geothermo-barometry and fluid inclusion studies to find out their evolution and fluid content and to make a comparison with other
Detailed major and trace element analysis and fabric analysis has been used to study special peri... more Detailed major and trace element analysis and fabric analysis has been used to study special peridotite xenoliths showing unusual tabular equigranular (flattened) texture (Fig. 1) which were found in Plio-Pleistocene alkali basalts from the Bakony—Balaton Highland Volcanic Field (Hungary). The peridotites are relatively clinopyroxene poor (~ 5 vol%) and reflect depleted major and variable trace element compositions. Crystallographic preferred orientation patterns of olivine and orthopyroxene crystal axes were analyzed with universal stage. In case of olivine, the activation of multiple slip systems: (010)[100] and (100)[001] is indicated, whereas the deformation micromechanisms of orthopyroxenes are suggested to be complex. We suggest that the observed orthopyroxene orientation patterns are the result of multistage (at least two) deformation events, which are supposed also to be responsible for unusual orientation patterns of olivines. The orientations in the stress fields of the subalternate deformations were significantly different. These results corraborate well with geophysical models proposing that the Pannonian Basin was formed under varying stress fields. The flattened equigranular xenoliths are suggested to represent a structural domain within the subcontinental lithospheric mantle beneath the volcanic field with predictable seismic characteristics. The occurrence of flattened domains in the upper mantle may considerably influence the percolation and residence time of the mantle melts and fluids.
Due to the increasing number of presentations and publications dealing with fluid and melt inclus... more Due to the increasing number of presentations and publications dealing with fluid and melt inclusions, it became apparent that it would be worth compiling auniform, Hungárián terminology. This study is based on the glossary compiled by L. W DIAMOND in 2003. Összefoglalás A fluidum-és olvadékzárványokkal foglalkozó előadások, dolgozatok és publikációk számának növekedésével felmerült az igény az egységes, magyar nyelvű terminológia alapvető fogalmainak rögzítésére. A szótár alapját L. W DIAMOND 2003-ban publikált szószedete képezi. Bevezető 2005-ben, az olaszországi Sienában megrendezett XVIII. European Current Research on Fluid and Melt Inclusions (ECROFI XVIII) konferencián a résztvevők számát tekintve a rendező olaszok után a magyaroké volt a legnépesebb " delegá ció". A konferencián egyértelműen kiderült, hogy a magyar szakemberek sikeresen alkalmazzák a fluidum-és olvadékzárványok vizsgálatát különböző földtani kérdé sek megválaszolására is. Amint azt a konferencián ...
Geological Society, London, Special Publications, 2015
We have investigated two buildings covered with Zsolnay glazed architectural ceramics in Budapest... more We have investigated two buildings covered with Zsolnay glazed architectural ceramics in Budapest (Hungary), one located in the densely built-up area of the city centre with a high traffic rate and one in a city quarter with moderate traffic and more open space. A black crust layer, containing a large amount of artificial particulate matter with different size and chemical composition, was observed on the ceramic material of both buildings, whereas weathered glaze was detected only on the ceramics of the building situated in the city centre. In this paper, our goal is to reveal the role of the particulate matter in the degradation of architectural ceramics. For this reason the attic dust and settled dust from the roofs of the studied buildings were collected. In the attic dust, besides the natural particles of geological origin, three types of artificial particles typically with spherical shape (spherules) were also distinguished: aluminosilicate (two subtypes), carbonaceous, and ir...
ABSTRACT Orthopyroxene lattice preferred orientation (LPO) in spinel lherzolite xenoliths from Sz... more ABSTRACT Orthopyroxene lattice preferred orientation (LPO) in spinel lherzolite xenoliths from Szentbekkella (Bakony-Balaton Highland, W-Hungary, Central Pannonian Basin), with special tabular textures was studied, using universal stage measurements. LPO patterns of orthopyroxene show a (001) maximum parallel to the lineation in the foliation plain and another maximum perpendicular to the lineation and the foliation. The pattern of the (010) plains also displays a double maximum similar to that of (001). The pattern of the (100) plains displays a single maximum perpendicular to the lineation in the foliation plain. Only very few orthopyroxenes display the ``normal&#39;&#39; LPO pattern: 001 parallel to the lineation and the foliation and 010 perpendicular to both. Olivine LPO&#39;s are normal, (100) plains are in the foliation parallel to the lineation, whereas (010) is perpendicular to the lineation and foliation, both showing single maximums. The orthopyroxenes are more resistant to recrystallization than olivines and may preserve earlier deformation states of the mantle. We suggest that observed orthopyroxene patterns are due to a deformation predating the deformation that recrystallized the olivines in the mantle. The orientations of the stress fields of the two deformations were significantly different, almost perpendicular. These results correspond to early geophysical modeling, suggesting that the Pannonian Basin was formed by a two-stage deformation process and may also provide information on the genesis of these special textural types.
ABSTRACT There are several localities in the Carpathian-Pannonian region where Plio-Pleistocene a... more ABSTRACT There are several localities in the Carpathian-Pannonian region where Plio-Pleistocene alkali basalts lavas and pyroclasts on the surface contain ultramafic xenoliths originating from the upper mantle. One of these occurrences is the Nógrád-Gömör Volcanic Field which is located in the northern part of the Pannonian Basin. Xenoliths from this area have undergone to various petrologic and geochemical studies in the past few decades, however, there is a lack of examinations focusing on crystallographic orientation. A method based on measurements with electron backscatter diffraction (EBSD) can provide insight into crystal preferred orientations of olivine and orthopyroxene - the major rock forming minerals of the mantle xenoliths. 14 lherzolites from 7 quarries of the Nógrád-Gömör Volcanic Field with previously studied petrography and mineral major element chemistry were selected to be measured with EBSD, for the purpose of determining olivine and orthopyroxene crystal preferred orientations, which are usually the result of a change in the physical conditions of the upper mantle (p, T, stress, strain, etc.). The distribution of crystallographic axes in olivines can be divided into three distinctive groups based on the alignment and directions of the a, b and c axes. These distribution groups are more or less related to the macroscopic texture and show a correlation with olivine J-indexes, which indicate the strength of the xenolith fabric. There is also a link between crystallographic orientations and calculated equilibrium temperatures. Our results show that samples from the southern part of the Nógrád-Gömör Volcanic Field (Bárna-Nagykő) display overally lower equilibration temperatures than those collected in the central part (Babi Hill and Medves Plateau). This difference in temperature, and hence in the estimated depth of origin may be responsible for the observed distribution of olivine crystal axes. Nevertheless, various crystallographic orientations suggest that there may be more deformation mechanisms that have activated on distinct levels of the mantle beneath the NGVF.
ABSTRACT We have reconstructed the compositional evolution of the silicate and carbonate melt, an... more ABSTRACT We have reconstructed the compositional evolution of the silicate and carbonate melt, and various crystalline phases in the subvolcanic reservoir of Kerimasi Volcano in the East African Rift. Trace element concentrations of silicate and carbonate melt inclusions trapped in nepheline, apatite and magnetite from plutonic afrikandite (clinopyroxene-nepheline-perovskite-magnetite-melilite rock) and calciocarbonatite (calcite-apatite-magnetite-perovskite-monticellite-phlogopite rock) show that liquid immiscibility occurred during the generation of carbonatite magmas from a CO2-rich melilite-nephelinite magma formed at relatively high temperatures (1,100 °C). This carbonatite magma is notably more calcic and less alkaline than that occurring at Oldoinyo Lengai. The CaO-rich (32-41 wt%) nature and alkali-“poor” (at least 7-10 wt% Na2O + K2O) nature of these high-temperature (&gt;1,000 °C) carbonate melts result from strong partitioning of Ca (relative to Mg, Fe and Mn) in the immiscible carbonate and the CaO-rich nature (12-17 wt%) of its silicate parent (e.g., melilite-nephelinite). Evolution of the Kerimasi carbonate magma can result in the formation of natrocarbonatite melts with similar composition to those of Oldoinyo Lengai, but with pronounced depletion in REE and HFSE elements. We suggest that this compositional difference results from the different initial parental magmas, e.g., melilite-nephelinite at Kerimasi and a nephelinite at Oldoinyo Lengai. The difference in parental magma composition led to a significant difference in the fractionating mineral phase assemblage and the element partitioning systematics upon silicate-carbonate melt immiscibility. LA-ICP-MS analysis of coeval silicate and carbonate melt inclusions provides an opportunity to infer carbonate melt/silicate melt partition coefficients for a wide range of elements. These data show that Li, Na, Pb, Ca, Sr, Ba, B, all REE (except Sc), U, V, Nb, Ta, P, Mo, W and S are partitioned into the carbonate melt, whereas Mg, Mn, Fe, Co, Cu, Zn, Al, Sc, Ti, Hf and Zr are partitioned into the silicate melt. Potassium and Rb show no preferential partitioning. Kerimasi melt inclusions show that the immiscible calcic carbonate melt is strongly enriched in Sr, Ba, Pb, LREE, P, W, Mo and S relative to other trace elements. Comparison of our data with experimental results indicates that preferential partitioning of oxidized sulfur (as SO4 2−), Ca and P (as PO4 3−) into the carbonate melt may promote the partitioning of Nb, Ta, Pb and all REE, excluding Sc, into this phase. Therefore, it is suggested that P and S enrichment in calcic carbonate magmas promotes the genesis of REE-rich carbonatites by liquid immiscibility. Our study shows that changes in the partition coefficients of elements between minerals and the coexisting melts along the liquid line of descent are rather significant at Kerimasi. This is why, in addition to the REE, Nb, Ta and Zr are also enriched in Kerimasi calciocarbonatites. We consider significant amounts of apatite and perovskite precipitated from melilite-nephelinite-derived carbonate melt as igneous minerals can have high LREE, Nb and Zr contents relative to other carbonatite minerals.
Silicate melt inclusions are frequent in the phenocryst phases (quartz, plagioclase, orthopyroxen... more Silicate melt inclusions are frequent in the phenocryst phases (quartz, plagioclase, orthopyroxene, ilmenite and accessory minerals) of the Miocene silicic pyroclastic rocks of the Bükkalja Volcanic Field, Northern Hungary. These melt inclusions were trapped at different stages of magma evolution; therefore, they provide important information on the petrogenetic processes. The melt inclusions in the Bükkalja pyroclastic rocks show various textures such as (1) wholly enclosed type; (2) hourglass inclusions and (3) reentrant or embayment glass. Among the wholly enclosed type melt inclusions further textural subgroups can be distinguished based on their shape: negative crystal, rounded, elongated and irregular shaped. These various textures reflect differences in the time of entrapment prior to eruption and in the post-entrapment condition in the magma chamber. The largest textural variation was found in the quartz-hosted melt inclusions. However, the major element compositions of these melt inclusions do not differ from one another in the same unit. In general, compositions of the melt inclusions are similar to the chemistry of the glass shards. Comparing the composition of the quartz-hosted melt inclusions from three main ignimbrite units (Lower, Middle and Harsány Ignimbrite Units), slight differences have been recognized, suggesting distinct erupted host magmas. Melt inclusions from the andesitic lithic clast of the Lower Ignimbrite Unit could represent heterogeneous interstitial melt in the crystal mush zone at the magma chamber wall. The largest geochemical variation was found in the melt inclusion of the Middle Ignimbrite Unit, even in single samples. This compositional variation overlaps that of the rhyolitic juvenile clasts, but does not match that of the glasses of scoria clasts. We suggest that syn-eruptive magma mixing (mingling) occurred in a compositionally heterogeneous magma chamber of the Middle Ignimbrite Unit.
Segregation of magmatic fluids and their potential in the mobilization of platinum-group elements... more Segregation of magmatic fluids and their potential in the mobilization of platinum-group elements in the South Kawishiwi Intrusion, Duluth Complex, Minnesota-evidence from petrography, apatite geochemistry and coexisting fluid and melt inclusions, Ore Geology Reviews (2013),
We review deformation fabrics in mantle xenoliths from the central part of the Carpathian-Pannoni... more We review deformation fabrics in mantle xenoliths from the central part of the Carpathian-Pannonian Region (CPR) and, in combination with seismic shear wave splitting data, attempt to define patterns of upper mantle anisotropy. Our interpretations from both lines of evidence support a model for east-west oriented asthenospheric flow, decoupled (at least in part) from the overlying lithosphere. Mantle flow fields resulting from Tertiary indentation of Europe by the Adria micro-plate and the resulting Alpine orogen may thus have been an important factor in driving the eastward extrusion of lithospheric blocks in the CPR accompanied by lithospheric extension, rapid 'rollback' of the Carpathian subduction system, and its diachronous collision with the European craton. According to this model, eastward asthenospheric flow would add significantly to the effects of slab rollback and gravitational instability. Thus, opening of the Pannonian Basin, rather than being exclusively driven by 'slab pull' and gravitational instability, could have been resulted, at least in part, from mantle flow associated with the Adria-European collision and ensuing Alpine orogeny. Such models have also been proposed for analogous geodynamic scenarios such as the western and eastern Mediterranean, and western and southwestern Pacific regions, offering a potential generic model for backarc basin opening.
A Late Cretaceous lamprophyre dyke in the Villány Mts (S Hungary), situated in the Tisza unit, co... more A Late Cretaceous lamprophyre dyke in the Villány Mts (S Hungary), situated in the Tisza unit, contains abundant spinel lherzolite xenoliths with porphyroclastic textures. Mineral chemistry suggests a relatively fertile mantle, which experienced only 5–7% melt ...
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Papers by Csaba Szabó