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The Holocene has always been considered a crucial epoch where the major cultural steps of humankind took place. Understanding past Holocene climatic variability, shifts in vegetation, and faunal communities are among crucial challenges in predicting the upcoming changes of the natural environment. In Central Europe, the Krakow-Czestochowa Upland is one of the best study areas for detecting faunal, environmental, and climate shifts. For that reason, we choose to study the small vertebrate and mollusc communities of three archaeological sites with Holocene horizons: Sąspowska Zachodnia Cave, Ciasna Cave, and Male Rockshelter. We analysed the faunal community shifts, and we compared our results with the major Holocene sites in the area with the correspondence and cluster analyses. The environment and climate were reconstructed through Habitat Weighting, Quantified Ecology, malacological spectra and Bioclimatic methods. Environment and climate values showed a temporary replacement of the Late Glacial tundra and grasslands with boreal forest mixed with open wetlands during the Preboreal and then stable landscapes dominated by temperate forests. Models based on rodent data show that temperature and precipitation generally increased, starting from the Boreal, to reach values near, or sometimes overwhelm, the current climate values of the area during the Atlantic and Subboreal. The climate values obtained from herpetofaunal analyses show very slight changes between the Preboreal and the Atlantic (Ciasna Cave layers 3 and 4), except for the winter temperatures, whereas results obtained for Sąspowska Zachodnia Cave are probably biased by a very low number of recovered remains. Among rodents, a major negative oscillation detected in layers related to the edge of Early Holocene was related to the Preboreal Oscillation or long-lasting effect of the Younger Dryas.

First finds of small freshwater Crustacea in southern Bellsund (SW Spitsbergen) are presented. The remains of seven species of ostracods and three species of cladocerans were recovered from the bottom sediments of seven ponds in the region. The most abundant Arctocypris fuhrmanni Petkovski, Scharf and Keyser, 2016 was accompanied by the most widespread Candona rectangulata Alm, 1914, Limnocythere liporeticulata Delorme, 1968 and Tonnacypris glacialis (Sars, 1890) which are endemic to Arctic regions. New to the area Tonnacypris cf. mazepovae (Van der Meeren, Khand and Martens, 2009) was also encountered, being the first record of this species outside Northern Mongolia. Cladocerans were represented by the remains of Chydorus sphaericus (Muller, 1776), Daphnia pulex group Leydig, 1860 and Bosmina longirostris (Muller, 1785) for the first time noted in the bottom sediments in Spitsbergen. Significant differences in crustacean distribution occurred both between and within studied ponds presumably connected with the duration of active vegetation period and/or melt water delivery. The physical and chemical properties of the hostwater and/or some post-depositional processes could also affect the microcrustacean faunal distribution.

Although multiple Mesolithic cave sites have been recognised in Europe, the use of such sites by Early Holocene hunter gatherers was extremely scarce north of the Carpathians. Single Mesolithic artefacts have been found thus far only in six cave sites in Poland. The rich Early Mesolithic assemblage found in Bramka Rockshelter in southern Poland seems to be quite extraordinary in such a context. The site was excavated over 50 years ago, but the results have never been published or analysed beyond a short mention of child burial found in the Mesolithic context. The paper presents new radiocarbon dates obtained for the Mesolithic occupation and the child burial, showing the Early Holocene chronology of the Komornician assemblage and the Late Bronze Age/Early Iron Age chronology of the burial. The assemblage's techno-typological analysis allowed us to identify six human occupation phases at the site, with the most intensive phase connected to the Mesolithic. Comparative analyses of other Mesolithic assemblages from the region, together with an extremely high percentage of debitage found in the Bramka Rockshelter assemblage, allow us to discuss the possibility of identifying the site as a knapping workshop located in the vicinity of Jurassic flint outcrops.

The paper presents the results of multidisciplinary studies on the open-air loess site Katta Sai 2 located in thewestern piedmonts of Tian Shan in Uzbekistan. Two archaeological horizons contain features associated with theInitial Upper Palaeolithic (IUP) - both Levallois and blade/bladelet volumetric technology, together with anUpper Palaeolithic toolkit. The cultural traits observed in Katta Sai 2 might have local roots dating back to MIS 5aand can be found in so-called Obirakhmatian technocomplex determined in several archaeological sites in theregion. Thus, the obtained results question the hypothesis of non-local origins of IUP complexes associated withthe early modern human migration from the Near East to Mongolia along the piedmonts of Pamir and Tian Shan.Until reliable anthropological and genetic data are obtained, it seems to be too early to conclude about therelationship between modern human migration and the appearance of IUP assemblages, at least across thewestern parts of Central Asia.

During African Humid Period in the Holocene when the summer Intertropical Convergence Zone migrated to its northernmost position, the Qarun Lake in the Faiyum Oasis in Egypt was fed with regular inflows from the Nile River and rainfall brought by the Mediterranean winter circulation. Finely-laminated lake sediments, dated at 8.5–6.7 cal kyr B.P., were examined in terms of lithology, geochemistry, microfossils (diatom, pollen) and magnetic susceptibility. Based on the inferred geographical derivation of pollen, the environmental affiliation of diatom taxa and geochemistry of lake sediments, wind trajectories were distinguished, related to two main atmospheric circulation phases. During the earlier phase (8.50–7.83 cal kyr B.P.) there were northwestern wind trajectories followed by southern ones and during the later phase (7.83–6.70 cal kyr B.P.), the northern winds were followed by northwestern and southern ones. Northwestern and northern winds brought winter rainfall and caused water turbulence in the lake, and the southern winds were associated with regional aridification. This scenario of atmospheric circulation in northeastern Africa extends significantly our understanding of key modes of climatic variability and wind trajectories in the Early to Middle Holocene (Greenlandian to Northgrippian) transition.

Proxy data from pollen and mollusc indicator species, periglacial phenomena, changes in geometry of mountain palaeoglaciers and based on selected lithological and geomorphological features enabled reconstruction of the Late Pleistocene climate characteristics in Poland and adjacent areas. Climate during the Eemian was generally stable but with a distinct west-east gradient in summer. Strong influence of the Atlantic air masses moving to the east resulted in the annual precipitation over 600 mm. Climate instability in the late Eemian as well as during stadials and interstadials of the Early Weichselian was expressed by progressive cooling and increasing temperature difference between winters and summers, reflecting stronger continentalism towards the west, accompanied by decreased precipitation. Periglacial frost crackings and polygonal patterns indicated occurrence of permafrost in Poland already at about 49 ka BP and its occurrence until the termination of the last glaciation. These periglacial structures have developed at mean annual temperatures from −9 to −4 °C, with winter extremes up to about −25 °C. Mean summer temperature reached likely around 10 °C as suggested by palaeobotanic record. Palaeoglaciological studies of mountain glaciers across Europe allowed inferring their activity and sensitivity to climatic fluctuations during the Late Weichselian. The Weichselian of central Europe was controlled mostly by the southerly and easterly circulation dominated by climate cyclones and anticyclones, respectively. An inflow of air masses from the west was significantly limited and concentrated mainly within the so-called periglacial corridor between the Scandinavian ice sheet and the Alps. Such circulation pattern determined serious reduction of precipitation during the Last Glacial Maximum that reached 60% in relation to modern conditions. The following Late Pleistocene cold phases (Oldest and Younger Dryas) were slightly warmer and wetter with increasing contribution of the westerlies that were strongly dependent on progressing shrinkage of the Northern Hemisphere ice sheets.

The Eemian-Vistulian developmental history of the Ławy paleolake (Eastern Poland) has been studied by analysing records of micro- (pollen, Cladocera, Ostracoda), macrofossils (molluscs, mammal remains), the lithological record and radiocarbon dating from a 5.30 m sediment core. At Ławy, in the Paterebo stream valley, well-preserved mammal fossil remains accompanied by organic deposits have also been investigated. The results of the multi-proxy analyses suggest explicitly that the climate was the main driving force of the changes in terrestrial and aquatic ecosystems, and in the geomorphological processes in the catchment. However, we propose that the water level fluctuations were also an important factor in the modification of the aquatic assemblages. Pollen, cladocerans, molluscs and ostracods from Ławy indicate the existence of a small, shallow, well-vegetated paleolake during the warm Eemian climate optimum. In the final phase of the Eemian the lake was transformed into a mire. In the Early Vistulian, the variable hydrological conditions were the main driver force for the development of the study area. Finally the existence of the basin at Ławy was closely associated with periodic coexistence of limnic, telmatic and river environments.

For quantitative estimation of past water temperature of four Holsteinian (MIS 11) palaeolakes from eastern Poland, the oxygen isotope palaeothermometer was applied to shells of the aquatic gastropodsViviparus diluvianusandValvata piscinalis. The δ18O composition of their shells demonstrated the average growth-season water temperatures during the mesocratic stage of the interglacial (Ortel Królewski Lake), during its climatic optimum – theCarpinus–AbiesZone (Ossówka-Hrud, Roskosz and Szymanowo Lakes), and in the post-optimum (Szymanowo Lake). The calculation was based on δ18OShellvalues and the δ18OWaterassumed for the Holsteinian from the modern oxygen isotope composition of precipitation and the expected amount of evaporative enrichment. The mean oxygen isotope palaeotemperatures of Ortel Królewski lake waters were in the range of 18.1–21.9°C and were uniform for theTaxusandPinus–Larixzones. Ossówka-Hrud and Roskosz Lakes had mean temperatures of 17.4–21.0°C during the climatic optimum, whereas the temperature of Szymanowo lake waters was estimated at 20.6–21.7°C at that time. These values are concordant with the pollen-inferred July air temperatures noted during the Holsteinian in eastern Poland. Relatively high values of ~25°C in the post-optimum noted at Szymanowo were connected with the presence of a shallow and warm isolated bay indicated by pollen and mollusc records.

A research was conducted on the Holocene lake sediments from the full-cored FA-1 drilling at the southern shore of the Qarun Lake in the Faiyum Oasis in northern Egypt. Altogether 10 taxa of molluscs and 8 taxa of ostracods were identified in the examined deposits, with total amounts of 768 and 2872 individuals, respectively. The fauna was investigated with palaeoecological purpose and allowed for preliminary reconstruction of sedimentary environment in the lake. The occurrence of Valvata nilotica Jickeli, 1874 and Gomphocythere sp. in the lower part of the core and a low proportion of carapaces (2.4-28%) indicated freshwater and higher-energy conditions, respectively. Rapid expansion of Cyprideis torosa (Jones, 1850) at a depth of 18 m could point to very short saline episode in the lake. The increase in salinity and drop of water level were evidenced in the uppermost part of the core (4-3.5 m), when the lake was dominated by Hydrobia ventrosa (Montagu, 1803), Cerastoderma glaucum (Poiret, 1789) and C. torosa. The steady sedimentation in a shallow lake was also supported by considerable amount of complete ostracod carapaces (45%). The faunal assemblage and smooth valves of C. torosa suggested salinity of 14-25‰.

This study evaluates changes in the environmental and climatic conditions in the Faiyum Oasis during the Holocene based on diatom analyses of the sediment FA-1 core from the southern seashore of the Qarun Lake. The studied FA-1 core was 26 m long and covered the time span ca. 9.000 cal. yrs BP. Diatom taxa were abundant and moderately to well-preserved throughout the core sediments. Planktonic taxa were most abundant than the benthic and epiphytic forms, which were very rare and sparsely distributed. The most dominant planktonic genera were Aulacoseira and Stephanodiscus followed by frequently distribution of Cyclostephanos and Cyclotella species. The stratigraphic distribution patterns of the recorded diatoms through the Holocene sediments explained five ecological diatom groups. These groups represent distinctive environmental conditions, which were mainly related to climatic changes through the early and middle Holocene, in addition to anthropogenic activity during the late Holocene. Comparison of diatom assemblages in the studied sediment core suggests that considerable changes occurred in water level as well as salinity. There were several high stands of the freshwater lake level during humid, warmer-wet climatic phases marked by dominance of planktonic, oligohalobous and alkaliphilous diatoms alternated with lowering of the lake level and slight increases in salinity and alkalinity during warm arid conditions evident by prevalence of brackish water diatoms.

A cave site Shelter in Smoleń III (southern Poland) contains an approximately 2-m-thick stratified sequence of Upper Pleistocene and Holocene clastic sediments, unique for Central Europe. The sequence contents abundant fossil fauna, including mollusk, rodent and bat remains. The cave sites with long profiles of subfossil fauna present a great value for reconstructions of regional terrestrial paleoenvironment. We explore the stratigraphy of this site through analyses of the lithology and geochemistry of sediments, radiocarbon dating of faunal and human remains and charcoals, and archaeological study, as well as the paleoecology derived from the taxonomic composition of fossil faunal assemblages. Our data show that the entire period of the Holocene is recorded in the rockshelter, which makes that site an exceptional and highly valuable case. We present paleoenvironmental reconstructions of regional importance, and we propose to regard Shelter in Smoleń III as a regional stratigraphic stratotype of Holocene clastic cave sediments.

Marine Isotope Stage 3 is considered a period with several climate oscillations that drove the environments to rapid changes. To understand how these stadial-interstadial cycles affected southern Poland, we combined the results of eight proxies analysed in the samples from the old excavations and a new 2017 trench of Koziarnia Cave (Ojcow National Park, Krakow-Czestochowa Upland, Poland) in layers related to Middle Palaeolithic, Jerzmanowician, and Early Gravettian. Among the studied proxies were charcoals, pollen record, remains of malacofauna, and vertebrates (including rodents, birds and large mammals, and ZooMS analysis of fragmented bones). Moreover, sediment samples have been analysed for lipid composition (by Gas Chromatography-Mass Spectrometry, GC–MS). Despite several taphonomic issues, it was possible to recognise two oscillations. The first one, reflected in pollen record and lipid analysis, took place during Dansgaard-Oeschger (DO) 14 to 8 and included Heinrich Stadial (HS) 4. The second one, recorded by rodents and bird proxies, was related to DO 8/7 to DO 6 and included HS 3. Charcoal and large mammal proxies provided the broad context of our study. The Jerzmanowician occupation was connected with a relatively cold episode in a landscape characterized mainly by grassland and periglacial environments, while the Late Middle Palaeolithic and Early Gravettian groups settled the cave during milder climatic conditions, where environments were open with sparse boreal woodlands. Such trends provide additional arguments in a broad discussion on Middle-Upper Palaeolithic transition in Central Europe.

Stable oxygen and carbon isotope investigations were conducted on shells of the freshwater gastropod Valvata piscinalis from palaeolake deposits of Holsteinian age (Marine Isotope Stage 11) from eastern Poland. The isotope record of this species was used for the first time as an archive of environmental conditions for selected lakes between the protocratic stage and the post-optimum period of the interglacial. The lowest δ18O and δ13C values of −8.1 and −12.1‰, respectively, were recorded in the Picea–Alnus zone at Ortel Krolewski palaeolake. The sparse vegetation and low productivity of that time are reflected in the relatively low δ13C values. The first significant increase of temperature was recorded in the Taxus zone (i.e. an increase in δ18O). The higher temperature influenced the expansion of macrophytes, which stimulated enhanced photosynthesis. Similar mean δ18O values in the Taxus and Pinus–Larix zones imply no distinct temperature change. V. piscinalis populations from Ossowka–Hrud and Roskosz palaeolakes record variations in lake productivity during the climatic optimum of the interglacial (Carpinus–Abies zone). The δ18O values of that time are relatively high (up to −4.5‰) and reveal no significant differences between the lakes. Decreases of the oxygen isotope values in the Szymanowo lake reflect post-optimum cooling.

The Lake Qarun (Faiyum Oasis, northern Egypt) is a relic of the much larger Holocene lake. Past lake levels and extensions were reconstructed, based on setting of archaeological sites scattered along northern paleoshores of the ancient lake. However, geoarcheological works did not yield enough data to establish continuous environmental history of the lake. A deep drilling FA-1 on the southeastern shore of the lake, performed in 2014, supplied with a core, 26 m long that is the one of the longest lake sediment cores in northeastern Africa. The basal section of the core consisted of thin-laminated diatom marly deposits, underlain at the Late Pleistocene/Holocene boundary by coarse-grained sands. The sediment lamine were quite well developed, especially in the lower part of the core. Preliminary results indicated annually deposited sediment sequence with seasonality signals provided by microlamine of diatoms, calcite, organic matter and clastic material. Early Holocene varved sediments from the Faiyum Oasis supplied with exceptional paleoenvironmental data for northeastern Africa, which enriched a record from previous logs drilled at the southwestern margin of the Qarun Lake.

Although debris, loams and clays are usually regarded as typical cave sediments, loess and loess-like sediments are common among clastic cave deposits in the near-entrance facies of caves and rock shelters. Late Weichselian loess layers are very common in caves from the Krakow-Czestochowa Upland and were recognized in almost each excavated cave and rock shelter. These layers were initially dated to the LGM (Last Glacial Maximum), but new chronometric dating results are available that allow us to present a more detailed scheme of the geological age of the series. This paper evaluates the significance of Polish in-cave loess layers as correlative horizons. We present the lateral and vertical stratigraphy and lithological variability of cave loesses and their usefulness as lithostratigraphic markers. These features are especially important for archeology and paleontology, as cave sediments, including loess, are usually the carriers of archeological and paleontological material.

This paper presents the results of a large-scale fieldwork project of interdisciplinary studies on the Middle Paleolithic settlement in the western Tian Shan piedmont. A complex of newly discovered “loess Paleolithic” open-air sites near Yangiobod (Uzbekistan), Katta Sai, was excavated. The excavations allowed identification of a new variant of human adaptation in the regional Middle Paleolithic. In the light of the newest anthropological and genetic data, this new archaeological sites fit to the current studies on the relations between different human species during the Middle and Early Upper Paleolithic in Central Asia. Geoarchaeological investigation of the sites has shown that the Paleolithic assemblages of Katta Sai are not preserved in situ. Cultural levels suffered from rill erosion, and most of the artifacts were re-deposited by water flow, and accumulated in secondary positions on the bottom of the branched rill system. This paper aims to reconstruct the subsequent processes of the site formation and to present the complicated geological situation of the studied sites of the Katta Sai complex, with implication for the archaeological interpretation of Paleolithic assemblages of the region.

The wooden structures unearthed in 2012 during archaeological excavation in the courtyard of the Museum of Archaeology and History in Elbląg have been dated using the dendrochronological method to the period between 1245 and 1302, which allows them to be considered to be parts of a Teutonic fortress. The remains of the wooden building located directly on the prehistoric lacustrine sediments created a unique opportunity to reconstruct the near-shore sedimentation of the Drużno Lake. Geological, malacological and palynological methods were applied during the investigation. The results, compared with the ranges of both the Drużno Lake and the Vistula Lagoon, known from previous studies of the region, allowed the correlation of a phase of a deep lake with the “Roman Period”. Rapid shallowing of the lake occurred in the “Migration Period”. The final disappearance of the lake in the area of modern Elbląg occurred in the early Middle Ages.

The aim of the studies described in this article was to present the effect of rare earth elements on aluminium alloys produced by an unconventional casting technique. The article gives characteristics of the thin strip of Al-Si-RE alloy produced by Rapid Solidification (RS). The effect of rare earth elements on structure refinement, i.e. on the size of near-eutectic crystallites in an aluminium-silicon alloy, was discussed. To determine the size of crystallites, the Scherrer X-ray diffraction method was used. The results presented capture relationships showing the effect of variable casting parameters and chemical composition on microstructure of the examined alloys. Rapid Solidification applied to Al-Si alloys with the addition of mischmetal (Ce, La, Ne, Pr) refines their structure.

This paper focuses on the interactions between hominin settlements and the palaeoecological contexts of the Early/Middle Pleistocene, in the central European lowlands and highlands. The palaeoenvironmental data from twenty-one natural sites with pollen, vertebrate and/or mollusc records (e.g. Voigstedt, Dethlingen, Ossowka) are compared and discussed in regard to seventeen localities with clear hominin occurrence (e.g. Karlich, Stranska skala, Bilzingsleben, Vertesszolos, Schoningen). This contribution provides the first attempt of a large scale qualitative compilation of palaeoenvironmental and palaeoclimatic data from key, multidisciplinary investigated late Early Pleistocene and Middle Pleistocene archaeological and non-archaeological sequences in Central Europe, mostly from MIS 22 to MIS 9. As such, this work is key for our understanding of the potential impact of climate-environment conditions upon hominin settlement dynamics vs. sites preservation in the region. Lower Palaeolithic hominin in Central Europe occupied a variety of environments, and despite the fragmentary nature of the record, warm and humid climate and partly forested landscapes appear as the most favourable conditions for hominin settlements. Prior to 0.5 Ma the record is however limited and the earliest hominin settlements of Central Europe appear largely unexplored in comparison to other European regions. During MIS 11-9, the increase of both natural and anthropogenic records seems to highlight the better sedimentary record from that time period in comparison to the previous ones, and lessens the assumption of an intensification of hominin settlement and increase of population during MIS 11-9 in Central Europe, such as proposed in Western Europe.

International audience; The laminated lacustrine succession at Ossówka in eastern Poland, which is largely the equivalent of MIS 11c, is amongst the best‐developed sites in Europe that cover this time period. Close inspection of the depth interval between 35.0 and 42.5 m in a 55‐m‐long core shows an environmental crisis at a depth of 40.95 m that lasted approximately 800 years and resulted in almost complete extinction of fir (Abies) from the communities existing at that time. Geochemical analyses reveal a simultaneous increase in sulphur in the deposits and a change in stable carbon and oxygen isotope ratios towards higher values, as well as a significant increase in the thickness of the laminae (up to 5 mm). Diatom studies show a clear increase in benthic diatoms in this interval, implying a decrease in water level. However, the predominance of such forms was probably caused by the elimination of planktonic diatoms by invasive blooms of Tetraedron, rather than lower lake levels, evidence of which was not noted in the pollen spectra. Hence, all these changes in the lake may have been triggered by the destruction of fir trees, the gradual decomposition of dead trunks and some inconspicuous geomorphological disturbances caused by wind throw. They resulted in a supply of micronutrients to the basin, an increase in varve thickness and rapid oscillations in the abundance and composition of algae and changes in the geochemical status of the lake. Rapid and significant drops in winter temperatures appear to be responsible for the extinction of fir. Alternatively, late frost in spring or hot and dry summers may have affected microsporophyll growth and the fir physiology as known from extant Abies populations. This environmental crisis, which is termed the Younger Holsteinian Oscillation (YHO), is noted at only a few sites. At Dethlingen (Germany), where hornbeam communities disappear at that time, a drop in summer temperatures is suggested to have been the driving force. We suggest that, at Ossówka, a drop in winter temperatures, late frost, or summer drought at the very start of the YHO are possible causes of the near‐extinction of fir.

The Qarun Lake in the Faiyum Oasis (Egypt) provides a unique record of Holocene environmental and climate change in an arid area largely devoid of fossil proxy records. Multiple lithological, palaeontological and geochemical proxies and 32 radiocarbon dates from the 26-m-long core FA-1 provide a time series of the lake's transformation. Our results confirm that a permanent lake appeared in the Holocene at c. 10 cal. ka BP. The finely laminated lake sediments consist of diatomite, in which diatoms and ostracods together with lower concentrations of ions indicate a freshwater environment at the end of the early and middle Holocene. This freshwater supply was closely associated with regular inflows of the Nile water during flood seasons, when the Intertropical Convergence Zone (ITCZ) migrated northwards in Africa, although it has probably never reached the Faiyum Oasis. Local rainfall, possibly connected with a northern atmospheric circulation, may have been important during winter. Several phases in the lake's evolution are recognized, represented by oscillations between deep open freshwater conditions during more humid climate and shallow fresh to brackish water during drier episodes. After a long freshwater phase, the lake setting has become more brackish since c. 6.2 cal. ka BP as indicated by diatoms and increasing contents of evaporite ions in the sediment. This clearly shows that since that time the lake has occasionally become partly desiccated. This is a result of reduced discharge of the Nile. In the late Holocene the lake was mostly brackish and then gradually turned into a saline lake. This natural process was interrupted about 2.3 cal. ka BP when a man-made canal facilitated water inflow from the Nile. The examined FA-1 core can be used as a reference age model of climate change in the Holocene and its impact on the development and decline of ancient civilizations in northeastern Africa.

The paper describes the impact of heat treatment on the change of mechanical properties of AlSi30 alloy with ultra-fine grain structure. The purpose of the research was to determine the optimal parameters of heat treatment of the alloy. The hypereutectic Al–Si alloy tested, with unconventional chemical composition, was obtained using rapid solidification, then consolidated and plastically processed. T4 and T6 heat treatments were performed in an UMSA—Universal Metallurgical Simulator and Analyzer. Supersaturation treatments were performed at constant time-temperature parameters, but with variable parameters of the ageing process. The tests conducted have improved the strength properties.

The oxygen and carbon stable isotope composition of Viviparus diluvianus shells was determined in the palaeolakes of the Holsteinian interglacial (MIS 11) in eastern Poland: the Ortel Krolewski, Hrud, Ossowka, Roskosz and Szymanowo lakes. The occurrence of V. diluvianus covers the Taxus zone, the so-called intra-interglacial cooling period (Pinus-Larix zone), the climatic optimum (Carpinus-Abies zone) and the post-optimal period with an undefined pollen zone. The isotope record of V. diluvianus shells allowed palaeoclimate and palaeoenvironmental reconstructions. δ18O and δ13C vary from −8.7‰ in the post-optimal period to −4.8‰ in the optimal period, and from −10.6‰ at the beginning of the Taxus zone to −4.2‰ at the climatic optimum, respectively. A positive correlation of the isotope curves indicates closed-water bodies, and only at Roskosz was some occasional overflow inferred. Higher oxygen isotopes correspond to an increase in temperature and/or enhanced evaporation, which is well marked in the Carpinus-Abies zone, whereas samples enriched in 13C are correlated with periods demonstrating a lower water level and higher productivity in the lakes. Episodes of lake shallowing and dense aquatic vegetation occurred in the Pinus-Larix zone and during the climatic optimum. The isotope ratios for the climatic optimum significantly exceed those of the other periods, thus pointing to warmer conditions. An estimation of relative changes of average summer temperatures using the δ18O/temperature gradient yielded variation of 1–2 °C within the lakes. Absolute temperature reconstructions indicate the effects of specific local conditions. Hence, V. diluvianus shells offer a reliable proxy in qualitative studies of interglacial lake records.

The profiles of calcareous tufa occurring in the Podhale Basin (Carpathians, Southern Poland) were subject to a detailed malacological analysis. Studies were carried out in 15 sites. Five of them represent the period of the Late Glacial and Holocene, and the remainder is tufa deposited during historical times. On the basis of malacological analysis, 10 faunistic assemblages were defined. Each developed under specific environmental and climatic conditions. The observed sequences of molluscan assemblages in vertical profiles were the basis for paleoenvironmental reconstruction, determining the main phases of climatic changes and the human impact on the natural environment. The faunal sequence observed indicates a cold climate and the predominance of open habitats in the Late Glacial, with progressing warming and the increasing significance of shaded habitats in the Early and Middle Holocene, as well as anthropogenic pressure in modern times. The results of malacological analysis were complemented with determination of the age of deposits by radiocarbon dating and the results of palynological analyses conducted in the sites of peatbogs occurring in Podhale. The reconstruction indicates similarities and differences in the paleogeographic development of mountain and upland areas of Central Europe.

Algorithmic complexity vulnerabilities are an opportunity for an ad-versary to conduct a sophisticated kind of attack i.e. on network infrastructure services. Such attacks take advantage of worst case time or space complexity of algorithms implemented on devices in their software. In this paper we address potential risks introduced by such algorithmic behavior in computer networks in particular on a stateful firewall. First we introduce the idea and theoretical background for the attack. We then describe in full detail a successfully con-ducted attack which takes advantage of the worst case computational complexi-ty of O(n2) of a hash table data structure used to store active sessions. The at-tack at hand is initiated from a network protected by an stateful firewall router feature to a remote server causing a DoS (Denial of Service) on an industry grade router. Our experimental results using a real life network topology show that by generating undetected low bandwidth but malicious network traffic causing collisions in the firewall’s hash table we cause the firewall to become unreachable or even announce a segmentation fault and reboot itself.

Contemporary materials engineering requires the use of materials characterised by high mechanical properties, as these precisely properties determine the choice of material for parts of machinery and equipment. Owing to these properties it is possible to reduce the weight and, consequently, the consumption of both material and energy. Trying to meet these expectations, the designers are increasingly looking for solutions in the application of magnesium alloys as materials offering a very beneficial strength-to-weight ratio. However, besides alloying elements, the properties are to a great extent shaped by the solidification conditions and related structure. The process of structure formation depends on the choice of casting method forced by the specific properties of casting or by the specific intended use of final product. The article presents a comparison of AZ91 magnesium alloys processed by different casting technologies. A short characteristic was offered for materials processed by the traditional semi-continuous casting process, which uses the solidification rates comprised in a range of 5 - 20°C/s, and for materials made in the process of Rapid Solidification, where the solidification rate can reach 106 °C/s. As a result of the casting process, a feedstock in the form of billets and thin strips was obtained and was subjected next to the process of plastic forming. The article presents the results of structural analysis of the final product. The mechanical properties of the ø7 mm extruded rods were also evaluated and compared.

Szymanek, M. 2014. Environmental changes of the Mazovian (Holsteinian /~MIS 11) palaeolake near Szymanowo (eastern Poland) in the light of malacological analysis. Acta Geologica Polonica, 64 (2), 249–260. Warszawa. The malacofauna of the palaeolake deposits at Szymanowo (eastern Poland) was investigated. It represents the younger part of the climatic optimum of the Mazovian (Holsteinian) Interglacial (~MIS 11) and possibly the postoptimal period. The mollusc assemblage is composed of both standing and running water species, mostly connected with temperate climate. The presence of biostratigraphical indicators of the Mazovian, Viviparus diluvianus (Kunth, 1865), Lithoglyphus jahni Urbanski, 1975 and Pisidium clessini Neumayr, 1875, is noteworthy. Variability in the structure and composition of the assemblage enables palaeoecological reconstruction. Changes in the water-level, vegetation and energy conditions are inferred from the malacological succession. Three stages of the lake development were distinguished. The first one is connected with deeper conditions and predominance of V. diluvianus and L. jahni. The second one, dominated by Bithynia tentaculata (Linnaeus, 1758), records a fall of the water-level and the growth of aquatic plants, evidenced by high frequencies of Valvata cristata Muller, 1774 and Acroloxus lacustris (Linnaeus, 1758). The third stage corresponds to another rise of the water-level and an increase in V. diluvianus, L. jahni, Valvata piscinalis Muller, 1774 and Pisidium henslowanum (Sheppard, 1823), which evidence some higher energy conditions.

One of the methods to produce aluminium alloys of an uncommon composition and structure is by the combined process of casting with rapid solidification and the following plastic forming. When modern advanced methods of rapid cooling of the melt are used, the alloy structure solidifies as a powder in the atomiser or as ribbons when cast onto a rapidly rotating copper wheel. If optimum conditions for the process of casting and rapid consolidation are satisfied, it is possible to control some structure parameters like the size of the particles, the size of the precipitates, etc. Additionally, the production of aluminium alloys by rapid solidification allows introducing the alloying constituents that are incompatible with the state of equilibrium. The consolidation of material made by rapid solidification is achieved in one of the numerous variations of the plastic forming processes, among which the most commonly used are the direct extrusion and continuous rotary extrusion (CRE). This paper presents the results of the consolidation in the process of continuous rotary extrusion (CRE) of selected aluminum alloys with an unusually high content of alloying elements cast in the process of rapid solidification by melt spinning and crushed in a high-speed cutting mill to as ”chips”.

The paper presents the technological aspect of the process of casting, crushing and plastic consolidation of semi-finished products from magnesium alloy. The aim of this study was to produce by the rapid solidification process a magnesium alloy from the MgAl9Zn1 family in the form of ribbons with ultrafine grain structure. The material cast in the melt spinning device was next crushed and subjected to the operation of cold consolidation and hot extrusion. The paper presents different stages of the process, including initial characterisation of the obtained material.

The article presents the change in mechanical properties of AlZn9Mg2.5Cu1.8 alloy resulting from the process of solution heat treatment and aging. The heat treatment was performed on a unique UMSA (Universal Metallurgical Simulator and Analyzer) device. The aim of the study was to determine optimum heat treatment parameters for the tested alloy of ultrafine grain structure obtained by Rapid Solidification (RS). To achieve this purpose, heat treatment to the T4 and T6 condition was carried out. The solution heat treatment was carried out at a constant temperature of 460 °C for 2 hours, while the time - temperature parameters of the aging process varied. The treatment undertaken resulted in improved mechanical properties.

A complex of clays and sandy-silt deposits with mollusc remains covered by a till correlated with the Main Stadial of the Vistulian (Weichselian) Glaciation was investigated at Wildno in the Dobrzyn Lakeland (Polish Lowland). A few taxa of snails: Bithynia tentaculata, Valvata piscinalis, Theodoxus cf. fluviatilis, Valvata sp., Viviparus sp. as well as bivalves Pisidium cf. amnicum and Sphaerium sp. were identified amongst poorly-preserved shell fragments. No pollen grains were present in mollusc-bearing deposits, whereas the pollen spectrum of clays lying below the latter points their accumulation in oligotrophic water body in a cool climate (Pediastrum kawraiskii) and woodless area. Radiocarbon age of shell detritus (4 samples) ranges from >43.7 cal ka to c. 32.1 ± 0.8 cal ka. Both the geological situation and the results of dating suggest that sub-till sediments with molluscs were deposited in the upper part of Interplenivistulian (MIS 3) = the Grudziądz Interstadial, while accumulation of clays may be correlated with its earlier and cooler part.

Lake deposits of the Holsteinian (Mazovian) Interglacial from eastern Poland are characterised by a rich occurrence of mollusc shells. Mollusc assemblages from five sites: Ortel Krolewski, Szymanowo, Ossowka, Hrud II and Roskosz are presented. Populations of the snail Viviparus diluvianus (Kunth) are subjected to biometric analysis to verify how climatic changes in the Holsteinian Interglacial influenced the shell morphology. The pollen analysis allows assignment of sediments from different sites to the certain parts of the interglacial, characterised by influences of maritime or continental climates. A combination of palaeobotanical and mollusc data shows that variability in shell morphometry of V. diluvianus is strongly connected with climate conditions. The strongest correlation with the climate shows slimness of the shell. It appears that during the periods with predominating oceanic climate the mean slimness of the shell increases, smaller and wider individuals are typical of the climate with continental features and lake shallowing. Thus V. diluvianus shells from eastern Poland are used to reconstruct climate from Taxus zone up to the end of the climatic optimum of the Holsteinian (Mazovian) Interglacial = MIS 11 (Carpinus–Abies zone).

Sediments of palaeolakes located in eastern Poland represent the Holsteinian (Mazovian) Interglacial, which corresponds to the Marine Isotope Stage 11 (MIS 11). Some of these sediments are characterized by an extremely rich occurrence of mollusc shells. A total of 1795 specimens of the snail Viviparus diluvianus were measured from 5 samples collected from a succession of lake deposits at Ortel Krolewski. The sample from the lowermost part of the succession (2.5 m) represents the Picea-Alnus pollen zone of the Holsteinian Interglacial. Samples from 2.0, 1.5, 1.0m are related to the Taxus Zone. Samples collected from the uppermost part of the succession (0.5 m) correspond to the Pinus Zone representing the so-called intra-interglacial cooling. The population of V. diluvianus displays variability correlated with climatic changes. The population from the Taxus Zone is characterized by a higher content of mature forms compared to the earlier population from the Picea-Alnus Zone. Because the mature individuals are slimmer than the juvenile forms, their last whorl is relatively lower and the aperture relatively smaller. In populations from the Taxus Zone the mean slimness of the shell therefore increases, followed by a decrease in the mean relative height of the last whorl and the mean relative aperture height.

The AlSi30 alloy obtained by melt spinning in the Rapid Solidification process, after fragmentation and consolidation, was subjected to plastic forming. As a result, extrusions in the form of 18 mm rods were obtained, and after forging and heat treatment (T6) were tested for selected functional properties. Mechanical properties, corrosion resistance and tribological properties were determined. Finally, a material with unconventional chemical composition was obtained, which confirmed its applicability for, among others, components operating in the transport industry, mainly pistons.

The purpose of this study was to produce by Rapid Solidification process an alloy with Si content exceeding 20%.

In recent years, magnesium alloys have gained widespread popularity as construction materials. This is due to their low density, high strength properties, and advances in their production technology. Properties of magnesium alloys depend primarily on the type, quantity, and quality of elements present in their composition. It is therefore necessary to carry out research on the further optimisation of the production technology of these alloys. This article presents the results of studies carried out in order to determine the type, form, and parameters of the process of introducing selected alloying elements to magnesium in a manner which enables the manufacture of alloys with predetermined chemical composition. As part of the work, elements such as Al, Zn, Mn, Zr, Si, Cu, Ca, as well as rare earth elements (RE) were introduced into the liquid magnesium. The alloying elements were introduced into the melt at different temperatures in either a metallic form or as master alloys. While conducting studies, respective solubility graphs were plotted for the alloying elements showing the time taken for each element to dissolve to the required form at a specific temperature and concentration. The studies resulted in the development of several techniques of introducing selected alloying elements, which enabled the manufacture of various types of alloys.