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Abstract Urbanization has resulted in the widespread development of built-up areas, often without considering the local geology and geomorphology. To improve risk assessments related to landslides, it is essential to determine the physical and chemical properties of sediments. The aim of this study is to exemplify an already mobilized and reworked layer based on granulometric properties of the sediments and characterize the chemical and physical properties which have changed during or after the mass movement. Ten red clay layers were sampled near Kulcs (Hungary) from a sliding surface and its environment. We measured grain size distribution, major element and modal composition, furthermore, conduct particle shape analysis, respectively. Grain size distribution suggest that samples from the sliding surface are weathered, with the exhibiting reworking characteristics. We calculate the weathering index from the major elements, which, in combination with the particle shape analyses of the silt fractions, indicate that the morphological parameters of the samples are in relation with weathering index. According to our results, while a fresh sliding event leaves marks on the granulometric properties, the main process which affects the grain morphology is the chemical abrasion (post the mass movement) and not the landslide event.

The present study is a review of publications regarding special aspects of the mineralogy of the Kaba meteorite, clay minerals, hydrous phases, and organic matter. In Section 1, the history of fall and finding of the meteorite and the first classical mineralogical description in the Year 1961 are mentioned. The most frequent alteration product of primary silicates and the glassy matrix is Fe-bearing saponite. By modelling of hydrothermal alteration of Allende-type meteorites, artificial saponite could be produced. The thermodynamic study proved the possibility of hydrous neoformation of silicates and magnetite at low temperatures, mostly below 100°C. The formation of Fe-rich external rims in forsterite grains by hydrothermal action was demonstrated by electron probe microanalysis and scanning electron microscopy-cathodo-luminescence methods. Foliation in CV3 carbonaceous chondrites indicates that the Kaba meteorite is derived from the external, shallow zone of the parent body. A combination of X-ray power diffraction (XRD) and Mössbauer spectroscopy made the exact modal analysis of CV3 chondrites possible, including Kaba. The study of alteration by in situ determination of stable oxygen isotope contents may provide constraints regarding the oxygen isotopic composition of the aqueous fluid on the CV parent asteroid. The degree of thermal metamorphism of the organic matter was determined by using Raman spectroscopy. The presence of aromatic and aliphatic, saturated and unsaturated hydrocarbons, and various amino acids was demonstrated. The non-biogenic origin is more probable; however, there are textural and mineralogical observations that may indicate also the biogenic origin of organic matter. In addition to the review of the literature above, as an appendix, shortly new XRD investigations of the authors are reported that indicated smectite-like phases in a thin section made of the meteorite.

The Gabčíkovo-Nagymaros waterworks construction on Danube river in Slovakia (1977−1992) was followed with major ecological consequences. The water level and flow velocity was decreased in the original by-passed channel in order to keep high water level for shipping in the bypass canal. The decrease in discharge and lowering flow velocity resulted in the channel narrowing and increase in the vertical accretion magnitude in new floodplain pockets along both sides of by-passed channel. What is more, anthropic intervention in form of groynes structures built for channel adjustment before 1992 dramatically accelerated this process. Vegetation colonisation took place on the new floodplain. In this paper, we analysed land cover changes - vegetation succession using aerial photographs taken in 1986, 1996, 2004 and 2013 as well as field surveys. After the flood in 2013, the area of the new floodplain reached 57% (310 ha) of the original channel area.

Diffuse Reflectance Spectroscopy (DRS) is a rapid, relatively new method in Quaternary research to analyse sediments and paleosols. This method takes into account clay mineral content, amount of Fe-bearing minerals and grain size composition of samples, simultaneously. Different Quaternary sediment samples were chosen for characterization and comparison their reflectance curves to detect the essential spectral properties of different paleosols and parent materials. Samples of different sediment types and paleosol variants were investigated from a loess-paleosol sequence from Malá nad Hronom (Slovakia) and from a fluvial-aeolian sediment complex from Pilismarót (Hungary). Five investigated curve sections were separated as the best indicators of reflectance properties of DRS curves. Spectral properties of samples were compared by using the length of investigated curve sections. This investigation showed quantifiable differences between the units of Pleistocene sediment successions, based on the reflectance properties. The influence of pedogenic processes was properly detectable. Significant discrepancies were observed between reflectance curves of well-developed paleosols and parent material samples in the visible and near-infrared range. Differences between the weak developed paleosol layers and their parent materials were only observed in the visible range. Fine sand, sandy silt and loess materials could be separated from each other based on the intensity of entire reflectance curves. [ABSTRACT FROM AUTHOR]

The Visegrád Gorge of the Danube evolved around the Plio-Pleistocene boundary. The Danube became the absolute base level of the streams in the south-eastern Börzsöny Hills. The tributaries of the Danube dissected the previous ancient surface creating geomorphological levels which correlate with the fluvial terraces of the Danube. Based on the determination of the dissected, ancient surfaces and other relict landforms of the south-eastern Börzsöny Hills, correlations were carried out between the evolutionary stages of the surfaces above and the fluvial terraces of Visegrád Gorge. To get relevant information, GIS methods, statistical, sediment and geomorphologic analysis were applied. The fluvial origin of the terraces situtated at higher altitudes of the Visegrád Gorge is doubtful. The results of this study comfirmed that the terrace are the remnants of an ancient relief which evolved before the Plio-Pleistocene boundary. [ABSTRACT FROM AUTHOR]

Abstract The purpose of our research is the environmental reconstruction of an important part of the Ripa Pannonica (limes), the Roman frontier system in Pannonia province. The study area is between the present Komárom, Tata, Dunaalmás settlements in Hungary. The legionary fortress of Brigetio was located along the Danube, forming part of the town of Komárom, Hungary. The camp and the settlement were bordered by the Danube on the north and by an aband oned river subchannel on the south. Using this riverbed and the valley of the Fényes stream flowing into it the Romans constructed a dam and created a wetland area, which might have had a defensive role. We prepared an environmental reconstruction based on geomorphological research, field work, GIS analysis, archive maps and historical sources and made the reconstructed digital topographic model of the study area. We also assessed the relationship between the geomorphological features and the anthropological landscape-shaping impacts. The settlement lied on the higher level of floodplain of the Danube river. The accumulation of the higher floodplain's sediments can be dated to the end of the Atlantic and first half of the Subboreal. The higher floodplain was finally formed in the last third of the Subboreal phase. At this time, at the end of the Late Bronze Age, the riverbed (the Danube subchannel) lying south of Brigetio's island was formed. This riverbed became abandoned at the end of the Subboreal phase, in the Early Iron Age. The marsh resulting from the Roman dam construction was present up until 1747, when S. Mikoviny dismantled the flood-gates and drained the area. Its history can be followed on archive maps, such as G. G. P r i o r a t o (1672), L. F. M a r s i g l i (1726) and S. M i k o v i n y (1746). [ABSTRACT FROM AUTHOR]