Északkelet-magyarországi és északnyugat-romániai középső neolit festett kerámiák festékanyagának azonosítása Fourier-transzformációs Infravörös Spektrofotometriai (FTIR) módszerrel

Middle Neolithic painted ceramics of the northeastern Great Hungarian Plain region have been enriched with new assemblages in Hungary in the last decade. Based on the newly excavated sites, the theory of the different developmental patterns of the neighbouring Hungarian and Romanian part of the Szatmár Plain, previously proposed by Romanian researchers, came into new light. Gh. Lazarovici and C. Virag assumed, that the second period of the Piscolt group shows the fl ourishing of the Middle Neolithic ceramic painting in the Romanian side, while at the same time in Hungary the painting was reduced, and incised decoration increased. The decreasing rate of the painted pottery in the Hungarian Szatmár and Szamos region was explained by its greater distance from the bitumen sources located in the Bihor area. The extensive utilisation of raw bitumen in the questioned region has been mentioned in Middle Age written records and also industrial historical papers in the Modern Age. In the present paper we publish the results of our complex analytical and experimental investigations. First of all by using FTIR spectroscopy we performed comparative analysis on painted pottery samples from Romanian and Hungarian sites and a raw bitumen sample collected from Suplacu de Barcau. The fi rst examination disproved the use of bitumen as ceramic painting, since in all cases the black residues on the pottery surfaces were proved to be wood tar. This result is not so surprising if we consider that the use of wood tar was a Pan-European phenomena in prehistory, while the Neolithic use of bitumen was reported only from the Near East. The painted sherds were compared with experimentally produced wood tar, and with one Early Bronze Age pot from Döge, which was pierced with one hole on the base. The interior of the base fragment showed carbonised remains and on the exterior and within the pierced hole thick and black tarry substance was identifi ed. It can be assumed that we are dealing with a retort, used for distillation of wood tar. The chemical composition of the black residue shows similarity with the experimentally produced tar and with the Neolithic samples as well. Our results demonstrated the utilisation of wood tar in the Middle Neolithic eastern Great Hungarian Plain region as well as later, in the Early Bronze Age, and it was proved that the spread of Neolithic painted pottery was not depended on the bitumen sources of the Romanian Bihor area

Kriminalisztikai üvegvizsgálat a Nemzeti Szakértői és Kutató Központban

Break-in, vandalism, car burglary – some of the crimes often involving glass breaking, in which physical-chemical expert examinations can help a lot in identifying the offender and solving the crime. In Hungary, the beginning of forensic glass examination dates back to the 1960s. In the nearly six decades since then, the methods used in the investigations have evolved a lot and expanded significantly. In addition to the classical physical parameters on which the comparison was based in the early days, the assessment of determination of origin by the most modern instrumental methods has given better-founded results, and besides it has also been possible to build a database. The aim of our paper is to present, after a brief historical overview, the process of forensic glass examination in the Hungarian Institute for Forensic Sciences, its applied methods, as well as the statements that can be made on the basis of the obtained results. In addition, in the light of a case study, we also illustrate in detail the difficulties and limitations of forensic glass examination. Arrived: 4 August 2020Accepted: 16 Sept 2020Betöréses lopás, rongálás, autófeltörés – csak néhány azok közül a gyakran üvegek törésével is együtt járó bűncselekmények közül, amelyekben a fizikai-kémiai szakértői vizsgálatok nagymértékben segíthetik az elkövető azonosítását és a bűnügy megoldását. Hazánkban a forenzikus üvegvizsgálat kezdete az 1960‑as évekre nyúlik vissza. Az azóta eltelt közel hat évtized során az alkalmazott módszerek sokat fejlődtek, a vizsgálati lehetőségek száma jelentősen bővült. A korai időkben az összehasonlítás alapjául szolgáló klasszikus fizikai paraméterek mellett, mára a legkorszerűbb műszeres módszerekkel a származási viszonyok megállapítása megalapozottabbá vált, ezen felül adatbázis építésére is lehetőség nyílt. Jelen írásunk célja egy rövid történeti áttekintést követően bemutatni a Nemzeti Szakértői és Kutató Központban zajló forenzikus üvegvizsgálat folyamatát, alkalmazott módszereit, továbbá a kapott eredmények alapján tehető szakmai megállapításokat. Ezek mellett egy esettanulmány tükrében részletesen szemléltetjük az üvegvizsgálattal kapcsolatos nehézségeket és korlátokat is. Érkezett: 2020. augusztus 4. Elfogadva: 2020. szeptember 16

Metamorphic and deformation history of the Mecsekalja Zone around the Szentlőrinc-1 well using individual quartz grains from drilling chips

The Mecsekalja Zone is a strike-slip fault zone that plays an essential role in the structural framework of South Transdanubia. The metamorphic and deformation history of the crystalline basement of the Mecsekalja Zone has been determined thus far based exclusively on a few surface outcrops and near-surface samples. The Szentlőrinc-1 (Sztl-1) well penetrated the shear zone at a depth of approximately 2 km and brought drilling chips from a 220-m-long section of the basement to the surface. The aim of this study is to reconstruct the metamorphic and deformation history of the Mecsekalja Zone along the Sztl-1 well using these tiny samples. These drilling chips consist of single mineral and rock pieces that are dominated by quartz grains. This study concentrates on the detailed analysis of quartz grains utilizing the physical conditions of metamorphic evolution as well as ductile and brittle deformation to determine the chemical composition and rheology of quartz. The evolution of the studied area can be determined by evaluating analytical data measured by Raman spectroscopy, LA-ICP-MS, and FTIR spectroscopy. These data suggest that the maximum temperature of the early regional metamorphism was 500–575 °C, the temperature of the subsequent ductile deformation was below 500 °C including recrystallization occurred between 400 and 475 °C. During the structural evolution of the study area, two independent, single deformation events occurred. The earlier ductile deformation event was followed by a brittle event through the reactivation of the former ductile shear zone. Our model is in accordance with previous results concerning the evolution of the Mecsekalja Zone, thus, the shear zone, with an identical evolution, can be extended toward the southwest at least to the Sztl-1 well

On the use of nominally anhydrous minerals as phenocrysts in volcanic rocks: A review including a case study from the Carpathian–Pannonian Region

The past decade has seen a great number of studies dealing with magmatic water contents and how these could be retrieved by the nominally anhydrous minerals’ (NAMs) trace structural hydroxyl (water) contents. Constraints have been made to magmatic hygrometry with clinopyroxene and plagioclase. Although results suggest that the method is more flexible and reliable than melt inclusion studies, they also indicate that the trace hydroxyl contents could still be overprinted by syn- and post-eruptive processes. Clinopyroxenes can hold more structural hydroxyl than plagioclases. A comprehensive review is presented with the inclusion of all published results so far to compile the available pieces of information. As a case study, micro-FTIR measurements are made of a representative set of plagioclase phenocrysts from the Börzsöny Mts. (Carpathian–Pannonian Region). The samples were selected to represent the progress of the volcanic activity in time and space, considering the petrologic and geochemical evolution of volcanic products in well-defined volcanostratigraphic positions. The syn- and post-eruptive cooling rate seems to have the greatest effect on water retention. This means that the systematic investigation of water in volcanic phenocrysts can contribute to distinguish the slowly and rapidly cooling parts of the volcanostratigraphic units

'Water' in quartz from various rhyolitic pyroclastic horizons: A new correlation tool?

Structural hydroxyl contents of quartz grains from various rhyolitic pyroclastic density current (PDC) deposits from the Bükk Foreland Volcanic Area, Hungary, were determined by using micro-FTIR spectrometry. Additional trace element analysis and SEM cathodoluminescence imaging were also performed. Structural hydroxyl content (expressed in water equivalent) of volcanic quartz ranges from ~2,0 to ~4,1 ppm, which is lower than those in quartz of igneous, metamorphic and hydrothermal origin. The incorporation of structural hydroxyl is mainly due to coupled H+ + Al3+ substitutions into Si-tetrahedral vacancies of quartz. In addition, the presence of molecular water is also obvious in (nano-)inclusions. The water fugacity (ƒH2O) just prior to the eruption seems to be the main factor controlling the concentration of structural hydroxyl as manifested in its almost homogeneous distribution regardless to the zonation of Al- or Ti-content. Quartz grains from the studied volcanic units are characterized by diagnostic absorption features between 3000 and 3550 cm-1, structural hydroxyl, molecular water, Al- and Ti-contents. This suggests the potential application of water content, the way of hydrogen incorporation and trace element chemistry of volcanic quartz as potential correlation tools. Moreover, a reasonable linear correlation is observed between the integrated area of Si-O bonds-related IR absorption features (between 2110 and 1440 cm-1) and sample thickness up to ~300 μm by studying unoriented quartz crystals. This may enable the analysis of separated quartz crystals without the need for preparing oriented thin sections

'Water' content of quartz from various rhyolitic ignimbrite horizons: results from unpolarized micro-FTIR analyses on unoriented grains

Structural hydroxyl contents of quartz grains from various rhyolitic pyroclastic density current (PDC) deposits from the Bükk Foreland Volcanic Area, Hungary, were determined by using micro-FTIR spectrometry. Additional trace element analysis and SEM cathodoluminescence imaging were also performed. Structural hydroxyl content (expressed in water equivalent) of volcanic quartz ranges from ~2,0 to ~4,1 ppm, which is lower than those in quartz of plutonic (granitic), metamorphic and hydrothermal origin. The incorporation of structural hydroxyl is mainly due to coupled H+ + Al3+ substitutions into Si-tetrahedral vacancies of quartz. In addition, the presence of molecular water is also obvious in (nano-)inclusions. The post-eruptive out diffusion of H+ during cooling seems to be the main factor causing the very low concentration of structural hydroxyl. This may be also manifested in the almost homogeneous distribution of structural hydroxyl regardless the considerable zonation in Al- and Ticontent. Although complete disappearance of structural hydroxyl was possibly hindered by the cooling effect of phreatomagmatism (excess water-magma interaction during eruption) and deposition in ashallow submarine environment. Moreover, a reasonable linear correlation is observed between the integrated area of Si-O bonds (between 2110 and 1440 cm-1) and sample thickness up to ~300 μm by studying unoriented quartz crystals. This may enable the analysis of separated quartz crystals without the need for preparing oriented thin section providing a more practical tool to determine structural hydroxyl concentrations

Systematic decrease of hydroxyl defect concentration in quartz phenocryst fragments within ignimbrites: implications for post-depositional diffusional loss of hydrogen

Ignimbrite-hosted quartz phenocryst fragments contain much lower hydroxyl defect than quartz in igneous rocks. Pre-eruptive and post-depositional loss of hydrogen were hypothesized as main processes for lowering the ‘original’ concentrations of hydroxyl defects. Our goal was to examine the hydroxyl defect concentration of quartz phenocryst fragments from various vertical positions above the base of pyroclastic density current – hereafter PDC – deposits. This is to monitor the vertical variations of hydroxyl defect concentrations to have an insight into potential post-depositional hydrogen loss and cooling history of PDC deposits. Ignimbrite-hosted quartz phenocryst fragments were examined from two different, thick ignimbrites in the Bükk Foreland Volcanic Area (North Hungary). Unpolarized micro-FTIR measurements on 23-35 unoriented crystal fragments from each sample were performed representing 4 different vertical positions of each site. Our results imply, that hydroxyl defect concentrations show a pronounced decrease upwards from the base of the deposits . The initial ~12 ppm hydroxyl defect concentration decreases to <3 ppm within few meters from the base. Thus, post-depositional loss of H is supposed to be the main factor causing the low hydroxyl defect concentration of quartz crystals in ignimbrites. Ignimbrites with different degree of welding are characterized by different hydroxyl defect concentrations of quartz phenocryst fragments at the same height above the base. A novel methodology which statistically evaluate the distribution of unpolarized absorbances for a given sample revealed that there may be either some accidental crystals incorporated during pyroclast transport at the base of these deposits or inhomogenities in hydroxyl defect concentrations due to non-equilibrium processes. Hydroxyl defect concentration in quartz from different vertical positions above the base is a relatively easily measurable proxy, which can provide further contribution to modeling the cooling speed, depositional temperature and original thickness of any quartz-bearing PDC deposits. We propose that ‘original’ hydroxyl defect concentration of quartz phenocrysts may only be preserved in a very thin layer (that cool very fast) at the base of PDC deposits where the cooling was instantaneous and no significant post-depositional H loss occurred. The original hydroxyl defect concentration may represent physical and chemical conditions in the magma chamber just prior to eruption