Santrauka This study examines the relationship between the quantity of landfill leachate and attenuation distance of inorganic contaminants in the groundwater of open, semi-open and closed hydrogeological systems. Nearly 2,000 groundwater samples were collected and 12 inorganic chemical parameters were investigated, of which NH4+, K+ and Fe were considered to be the most groundwater polluting chemical parameters. Analytical modelling of pollution migration, multivariate statistical techniques and a single factor pollution index method were applied for data processing. The results showed that irrespective of waste volume, the degradation coefficients of NH4+, K+ and Fe were by 36–90% higher in the groundwater of open hydrogeological systems, where attenuation distances were by 14–56% shorter compared with those in closed hydrogeological systems. Also, the degradation coefficients of NH4+, K+ and Fe+ in the groundwater of very small and small landfills were by 37–90% higher and attenuation distances were by 38–99% shorter compared with those in the groundwater of large and very large landfills. In the groundwater of very small and small landfills the difference between NH4+, Fe and K+ attenuation distance in open and closed hydrogeological systems was about 89–97% lower than the difference in large and very large landfills. This finding indicates that the quantity of leachate is the main factor of attenuation of contaminants in groundwater. The results obtained in this research may be used to predict the dispersion of pollution in the groundwater of landfills located in similar hydrogeological systems and to take environmental protection measures.
Raktažodžiai landfill; leachate quantity; inorganic contaminants; attenuation distance; hydrogeological systems
Santrauka The study was conducted using 14 hierarchical clustering ways and combining them with 4 inter-related sets of elements, i.e. the contents of Al, Ba, Ca, Fe, Ga, K, Mg, Mn, Na, Nb, P, Rb, Si, Sr, Th and Ti determined by EDXRF in 44 splits of 10 archaeological and 4 modern bricks, as well as in 38 clay samples from two quarries. Empirical scoring of tree dendrograms of archaeological samples helped to identify Complete Linkage, Weighted Pair Group Average and Ward’s methods as the most suitable for sourcing. Successful identification of geochemical clustering methods for fingerprinting sources of bricks is determined by the intrinsic features of the geochemical composition of stonework or quarries: their similarity, determined by the geochemical peculiarities of clay indicators, such as Al, Rb, Ga, K, Th, Fe, Ti and Nb, and differences, expressed by the elements that are more abundant in sands and silts (Si, Na), carbonates (Ca, Sr, Mg), organic matter (P) and other lithological-mineralogical tracers. It has been found that the mean values of the geochemical composition of the allied objects have much more useful fingerprinting properties. It is strongly recommended for source fingerprinting to select not only typical lithological-mineralogical samples, but also homogeneous sampling sets excluding possible outliers. It has been shown that each raw clay material has its own specific geochemical features. This is an essential useful feature for source fingerprinting using clustering of the objects of interest.
Raktažodžiai EDXRF analysis; inter-element correlation; hierarchical cluster analysis; cluster dendrogram; fingerprinting; scores; archaeometry
Santrauka The results of lithological, diatom analysis and radiocarbon dating of bottom sediments of small coastal lake basins along the Murmansk coast of the Barents Sea (the Kola Region, Russia) are presented. Sedimentary successions of two lakes reveal the presence of distinctive deposits, very different from the sediment above and below. These deposits are represented by erosional unconformity beds, gyttja and sand mixed with plant macrofossils, and characterized by changes in diatom flora and sand in a matrix of organic material. The sediments were deposited due to different catastrophic events: paleo-tsunami and paleo-earthquakes. According to radiocarbon analysis data, a tsunami occurred between 10,400–8200 cal yr BP and a paleo-earthquake occurred between 8200–7200 cal yr BP. We discuss various causes and mechanisms for the formation of disturbances in lake sediments, including the Storrega tsunami and paleo-earthquakes, which during and after deglaciation were strong and frequent.
Raktažodžiai coastal lake basins; paleo-earthquakes; tsunami deposits; seismic shaking; Kola Bay; Barents Sea; Kola region; Holocene
Santrauka A clearly erosional, asymmetrical structure with a large concentration of unsorted clasts (ranging from gravel to boulder size) in its deepest point is present in Weichselian glaciolacustrine, mainly fine-grained sediments exposed in an outcrop near Dukuli (NE Latvia). No traces of currents that were sufficiently strong to be capable to erode the sediments significantly have been encountered in the sedimentary succession under study, and such currents would certainly not have been capable to transport boulder-sized clasts. Neither are traces present of mass movements that could deposit the boulder-sized clasts. The glaciolacustrine setting of the succession, the deep scouring and the high concentration of large clasts must therefore be ascribed to erosion of the lake bottom by the keel of an ice raft that became grounded and gradually melted; the debris that was carried along by the ice raft was released and concentrated at the deepest point of the depression that had been eroded by it.
Raktažodžiai grounding; ice raft; plough marks; proglacial lake; Weichselian; Latvia
Santrauka This research paper represents interpretation of engineering geological and geotechnical conditions by using a direct shear device with a possibility to apply hydrostatic pressure during the experimental testing. In the authors’ opinion, the evaluation of in-situ hydrostatic pressure and reconstruction of it in the laboratory tests is a very important step in the determination of the engineering geological and geotechnical properties of the sand strength and its behaviour. To understand the influence of hydrostatic pressure on shearing strength results, there were performed direct shear tests with and without hydrostatic pressure. Obtained results clearly show the differences in the shearing strength analysed during this study. When the investigated sand sample was loaded with maximum hydrostatic pressure (σH = 100 kPa), the peak value of the angle of internal friction (ϕ’mean) was 21.24% higher compared to that of dry soil. No tendencies were found for cohesion.
Raktažodžiai sand; direct shear test; saturated sand; hydraulic head; hydrostatic pressure; shearing strength
Santrauka Karelia, like the entire Fennoscandian Shield, is a region with a low seismic activity. An example of the best-studied locality is a paleoseismic dislocation on Mount Vottovaara, which bears traces of disastrous Holocene geological events following the degradation of the last ice sheet. The evolution of the study area falls into three stages. At pre-Quaternary stage I, an uplifted block broken by numerous fractures and faults was formed. At glacial stage II, coarse clastic moraine was formed, the moving ice polished the crystalline basement surface and glacial scars were formed. At final deglaciation stages, the mountain top remained a nunatak. As Salpausselkä II marginal sediments retreated by about 70 km from the mountain, a postglacial stage in the region’s evolution, at which an earthquake occurred, began. It could have been triggered mainly by the consequences of the degradation of the Late Weischelian glaciations such as the rapid removal of the glacial load that contributed to the rejuvenation of various old faults. Changes in paleoecological conditions for the Mount Vottovaara area were reconstructed based on the results of lithological, palynological, diatom and radiocarbon studies of bottom sediments from a small lake on the mountain top. Vegetation dynamics from the Younger Dryas to the Subboreal period is presented. Small lake evolution stages were distinguished based on analysis of diatom complexes and the pollen and spores of aquatic and aquatic-subaquatic plants and Pediastrum algae. The data obtained show that minerogenic sediments were abruptly succeeded by organic in the late Preboreal-early Boreal period. The thickness of Boreal sediments and changes in the composition of diatom complexes and spore-and-pollen spectra suggest a depositional hiatus triggered by a strong earthquake which changed the water level of the pond and its basin structure. The earthquake is also indicated by numerous dismembered, displaced, thrown-away and shifted rock blocks and seismogravity downfalls. Deflation and other types of weathering are responsible for the formation of seide-shaped piles of blocks and boulders on the mountain top.
Raktažodžiai paleoseismic dislocation; sediment record; pollen, diatoms; vegetation changes; Pleistocene; Holocene
Santrauka Extraction of mineral raw materials is increasing due to economic development and must be a normal process under due control and environmental supervision. However, there are a number of sites where the exploitation was stopped and mining sites were abandoned without proper restoration. Also, there are sites where mineral resources were or are extracted illegally thus making significant damage to the environment and economy. In order to collect information on land impacted by mining and extraction activities, for the first time a special project was carried out for the entire territory of Lithuania. The project consisted of gathering of information on damaged areas from various sources, field surveys and systematization of collected data. In order to obtain volumetric data, a special technology of aerial photogrammetry was developed and successfully applied. It was detected that the number of damaged sites > 0.3 ha reached up to 3,300. It is estimated that a total amount of illegally extracted minerals in last 15–20 years could be up to 15 million m3. The aerial photogrammetry was proved as a relevant technology and this could be applied for the control of the restoration of damaged land as well as for the monitoring of hazardous geological processes, e.g. coastal erosion, karst.
Raktažodžiai UAV measurements; proved mineral deposits; indicated mineral resources; sand and gravel; quarries; illegal excavation
Santrauka One of the main tasks of this work is to investigate a different and new approach to coastal climate identification in the Baltic Sea’s coastal areas. A different approach of spatial correlation between solar net shortwave radiation flux and air temperature data helps to distinguish and derive areas which receive the same amount of energy but have a different average air temperature than the surrounding territories. Most of the successful climate classifications consist of three climatic variables (temperature, precipitation and temperature range). This work establishes that bivariate correlation maps of solar net shortwave radiation flux and air temperature can also be successfully used to identify local coastal climate around the Baltic Sea. The data used is the WorldClim global climate dataset and NOAH025_2.0 model output. Model data is used for calculating the correlation maps and is later compared to long-term air temperature range maps of the Baltic Sea’s coastal area. The study shows that in combination with standard classification methods, the research results can later be applied for classification of local coastal climates. Thus, the method proposed opens new potential to study coastal climate with a higher degree of accuracy. However, further studies are required to characterize the behaviour of this method for other than temperate climates.
Raktažodžiai Baltic Sea; coastal climate; solar radiation; air temperature change; climate classification