Relative Erosion Research Articles

Downstream evolution of the thermochronologic age signal in the Brahmaputra catchment (eastern Himalaya): Implications for the detrital record of erosion

The Namche Barwa massif in the eastern Himalayan syntaxis is characterized by very rapid exhumation and provides a significant proportion of the sediment flux carried by the Brahmaputra River. We present new detrital zircon fission-track (ZFT) and muscovite 40Ar/39Ar (MAr) data from modern sediments of rivers draining the eastern Himalaya. The cooling-age populations for both thermochronometers contain a characteristic <2 Ma signature related to the rapid exhumation of Namche Barwa, which can be traced hundreds of kilometers downstream from their source into the Brahmaputra foreland, despite dilution from downstream tributary catchments. To estimate present-day erosion in the catchments, we apply a mixing model based on linear inversion of the binned age distributions. The inversion predicts relative erosion rates in the syntaxial region that are an order of magnitude higher than those in upstream catchments, and about twice as high as those in the southern Himalayan catchments, consistent to first order with previous estimates of erosion-rate patterns in the eastern Himalaya. A comparison of the observed downstream evolution of age distributions with a sediment-flux model suggests that the ZFT signal can be explained by dilution from Himalayan tributaries only, whereas the MAr signal is also affected by selective sequestering (possibly through winnowing) of micas as they are transported downstream. Nevertheless, thermochronological ages <2 Ma provide a diagnostic signal of syntaxial exhumation in the sedimentary record of the eastern Himalaya; this study suggests the most robust signal to be recorded in the most proximal deposits with respect to the syntaxis.

Localized and distributed erosion triggered by the 2015 Hurricane Patricia investigated by repeated drone surveys and time lapse cameras at Volcán de Colima, Mexico

In October 2015, Patricia, a major category 5 hurricane, made landfall in western Mexico, resulting in 500 mm cumulated rainfall and lahar generation along the southerly directed Montegrande valley of Volcán de Colima. We monitored lahar deposition and erosion using time-lapse trail cameras and conducted repeated camera drone overflights, two days before and after the hurricane. Using photogrammetric processing we derive a unique dataset of high resolution digital terrain models and study the geomorphologic impacts of a single lahar event. Results reveal different types of erosion at 8 km distance from the volcano, with overland flow and rill networks, developing into major erosion gullies exceeding a depth of 4 m, as well as bank collapse, oversteepening and marginal erosion. We find alternating deposition and erosion zones that depend on general slope and valley width, and find that the overland flow related erosion is an important contributor to the bulking process of lahars. Moreover, this study shows that camera monitoring is very useful for studying the relationship between volcano landscape evolution and hydrometeorological extremes and for rapid assessment associated with single lahar events.

Erosion tribo-performance of HVOF deposited Stellite-6 and Colmonoy-88 micron layers on SS-316L

The present study deals with the analysis of erosion tribo-performance of Stellite-6 and Colmonoy-88 micron layers deposited on stainless steel 316 L by using high-velocity oxygen–fuel (HVOF) process. The average roughness of Stellite-6 and Colmonoy-88 deposited SS-316 L was measured as 5.69 and 6.67 μm respectively. The crack toughness of Stellite-6 and Colmonoy-88 deposited surface was evaluated as 19.8 ± 0.56 and 30.1 ± 0.29 MPa m1/2 respectively. Erosion wear experiments were performed by using a Ducom slurry pot tester at different process parameters. Results show that the relative erosion wear of SS-316 L and Stellite-6 was observed maximum at 30° impact angle whereas relative erosion of Colmonoy-88 was found maximum at 60°. Microhardness of SS-316 L was improved about 2.5–3.2 times with deposition of Stellite-6 and Colmonoy-88.

WATER EROSION UNDER THREE TILLAGE METHODS IN A CULTIVATION OF Eucalyptus benthamii

ABSTRACT Soil tillage influences the development of forests planted in the initial phase, which affects some hydrological processes and water erosion. The objective of this study was to quantify the water losses (WL) and soil losses (SL) by water erosion, between the second and third years of eucalyptus (Eucalyptus benthamii) crop, in an experiment located in southern Brazil, on a Humic Dystrudept. Was study three soil tillage treatments: i) subsoiling in downslope direction (SD); ii) subsoiling in contour on the slope (SC); iii) manual holes (MH). The plots had a dimension of 12 x 24 m, being the slope-wise length the greatest, monitored by tanks placed at the lower end for runoff collection. Runoff volume measurement and sampling for subsequent calculation of WL and SL was carried out weekly, corresponding to the rains accumulated during the week. The crop of eucalyptus in SD treatment, weakened the soil as to the water erosion in relation to the crop made in SC and in MH; the difference was 25% for the WL and 53% for the SL. Eucalyptus reforestation played an important role in the control of water erosion, regardless of the type of soil tillage. The SL due to water erosion were more influenced than the WL, regardless of the type of soil crop used. WL and SL are related to each other and to rainfall height in positive linear relationship, regardless of the type of soil preparation used for eucalyptus planting.

Sediments as a Part of the Soil Protection Legislation

Abstract The soil protection has a long tradition in Slovakia. Slovakia has a good and strict legislation on the soil protection. It also includes protection against erosion and degradation. However, there is a certain gap in the legislation in addressing the relationship between the lost soil and the land ownership. It is not clear how the land ownership is changed with soil particles movement along the slope, on which erosion occurs. Even more uncertainty regarding the land ownership occurs if the soil is transferred to the watercourses or water reservoirs, where the soil is transformed into sediments. On the European level, sediment management is not covered by specific regulations. The sediment management is partially addressed in several European directives directly or indirectly. The current legislation in Slovakia is creating economic and legal barriers to the return of the soil from the rivers and the reservoir to its original owners. The paper deals with the current state of explaining the problem with the soil erosion and sediment transport in relation to the valid legislation in Slovakia and the European Union. Legislation addressing the erosion and sediment is not just based on land ownership but also on principles for protection of the environment as the transfer of harmful substances to the soil or water.

Utilization of Flyash as Filler Material in Hybrid Polyester Composites for Improved Thermo-Mechanical and Erosion Wear Behavior

The present work was carried out for the utilization of major quantities of flyash as filler material in the short fiber reinforced polyester resin composites in various engineering and structural applications. The incorporation of flyash modifies the hardness, tensile, flexural, impact and damping behavior of the composites. It is observed that hardness, flexural modulus and impact strength of flyash filled composites increases with increase in the flyash filler contents. Whereas, with the addition of flyash contents it is observed that there is decrease in tensile strength and flexural strength. But beyond the 10 wt.-% flyash filler addition in the composite the flexural strength increases. At the end, the erosion wear behavior of all the composites has been studied by Taguchi experimental design. It is found that unfilled glass polyester composite suffers greater erosion loss as compare to particulate filled glass polyester composites. The eroded surface morphology is examined by SEM and the related erosion wear mechanism is discussed in detail.

Mapping spatio-temporal dynamics of the cover and management factor (C-factor) for grasslands in Switzerland

The decrease in vegetation cover is one of the main triggering factors for soil erosion of grasslands. Within the Revised Universal Soil Loss Equation (RUSLE), a model commonly used to describe soil erosion, the vegetation cover for grassland is expressed in the cover and management factor (C-factor). The site-specific C-factor is a combination of the relative erosion susceptibility of a particular plant development stage (here expressed as soil loss ratio SLR) and the corresponding rainfall pattern (here expressed as R-factor ratio). Thus, for grasslands the fraction of green vegetation cover (FGVC) determines the SLRs. Although Switzerland is a country dominated by grassland with high percentages of mountainous regions and evidence for high erosion rates of grassland exists, soil erosion risk modeling of grasslands and especially of mountainous grasslands in Switzerland is restricted to a few studies. Here, we present a spatio-temporal approach to assess the dynamics of the C-factor for Swiss grasslands and to identify erosion prone regions and seasons simultaneously. We combine different satellite data, aerial data, and derivative products like Climate Change Initiative (CCI) Land Cover, Swissimage false-color infrared (Swissimage FCIR), PROBA-V Fraction of green Vegetation Cover (FCover300m), and MODIS Vegetation Indices 16-Day L3 Global (MOD13Q1) for the FGVC mapping of grasslands. In the spatial mapping, the FGVC is extracted from Swissimage FCIR (spat. res. 2 m) by linear spectral unmixing (LSU). The spatially derived results are then fused with the 10-day deviations of temporal FGVC derived by FCover300m. Following the original RUSLE approach, the combined FGVC are transformed to SLRs and weighted with high spatio-temporal resolved ratios of R-factors to result in spatio-temporal C-factors for Swiss grasslands. The annual average C-factor of all Swiss grasslands is 0.012. Seasonal and regional patterns (low C in winter, high C in summer, dependency on elevation) are recognizable in the spatio-temporal mapping approach. They are mainly explicable by the R-factor distribution within a year. Knowledge about the spatio-temporal dynamic of erosion triggering factors is of high interest for agronomists who can introduce areal and time specific selective erosion control measures and thereby reduce the direct costs of mitigation as well as erosion measures.

Tourism and beach erosion: valuing the damage of beach erosion for tourism in the Hoi An World Heritage site, Vietnam

The Hoi An World Heritage site in Vietnam has faced increasing coastal erosion as a result of both natural and anthropogenic causes since the 2010s. Main drivers are the construction of hydropower dams on the Vu Gia and Thu Bon Rivers, illegal sand mining in the South China Sea, and sea level rise along the Central Coast Vietnam. Coastal erosion affects the tourism attraction of this area. A challenge for both the national government and the local authorities is understanding the nature of the contemporary coastal erosion; this includes the beach erosion and tourism relationship. This study deals with the damage valuation of the beach erosion in relation to the tourism revenue based on the hedonic pricing method. Cua Dai beach of Hoi An is structured into 23 beach sectors along the shore, each of which shows a relative homogeny in physical characteristics, anthropogenic activities, and socioeconomics. The beach value is function of morphological variables such as beach width and distance to the city center, and tourism variables such as tourist area, coastal businesses, the number of hotels, and the number of hotel rooms. The two-stage least squares (2SLS) of the custom-log model is the most accurate approach. The total projected revenue losses are more than an estimated 29 million US dollars by 2040. The present values of the total annual revenue losses in 2020, 2030, and 2040 are about 29.6, 21.4, and 14 million US dollars, respectively, at an interest rate of 5%. The results suggest mitigation strategies and policy recommendations. The proposal includes improving the adaptation capacity to coastal erosion using innovative, smart, and wise solutions. Beach nourishment and coastal defense structures can be sustainable management tools combating coastal erosion only if the multicausal coastal processes are properly considered and a detailed cost–benefit analysis is performed.

Changes in multiple ecosystem services between 2000 and 2013 and their driving factors in the Grazing Withdrawal Program, China

Quantitative assessment of ecosystem services in the Grazing Withdrawal Program (GWP) of China is required to understand the effectiveness of environmental protection programs and the sustainability of grassland ecosystems. This study focused on quantitative assessment of changes of key ecosystem services and their driving factors in the GWP from 2000 to 2013. Based on widely used biophysical models, including the GLOPEM-CEVSA model, the precipitation storage method, Integrated Valuation of Ecosystem Services and Trade-Offs (InVEST), Revised Wind Erosion Equation (RWEQ) and Underground Productivity Model (UPM), this study integrated multi-source data to analyze dynamic changes of regulating services, including carbon sequestration, water regulation, sand fixation and soil retention, and the provisioning service of grassland yield. For the GWP area during 2000–2013, the ecosystem pattern remained relatively stable and multiple ecosystem services showed overall improvement but there were local deteriorations. For the 14 years net primary productivity (NPP) and grassland yield (GY) increased substantially. Water regulation in forest, grassland and wetland/water body ecosystems improved slightly. The soil conservation function of the entire ecosystem was slightly enhanced with soil retention showing an increasing spatial homogenization and wind erosion having a decreasing tendency. Ecological restoration and reconstruction efforts and climate change helped to improve ecosystem services. Increases in both temperature and precipitation and ecological rehabilitation had a positive effect on vegetation restoration related to a marked increase of vegetation coverage. Increase in annual precipitation increased rainfall related erosion but also assisted water regulation. Reduction in wind speed effectively lowered the occurrence of wind erosion. Vegetation restoration directly increased NPP and GY, and was conducive to water regulation and soil conservation. However, grassland degradation still continued in local areas. Ecological programs applied to the grasslands of China should be continued. Adopting adaptive management approaches that facilitate the synergy of multiple ecosystem services are required to maximize their benefit to the people of China.

Effects of a sodium fluoride- and phytate-containing dentifrice on remineralisation of enamel erosive lesions\u2014an in situ randomised clinical study

ObjectiveThe objective of this work was to evaluate effects of a dentifrice containing sodium fluoride (1150 ppm F) and the organic polyphosphate phytate (0.85% w/w of the hexa-sodium salt) on in situ remineralisation of early enamel erosive lesions and resistance to subsequent demineralisation.Materials and methodsSubjects (n = 62) wore palatal appliances holding eight bovine enamel specimens with pre-formed erosive lesions. They brushed their natural teeth with the phytate test dentifrice (TD); a positive control dentifrice (PC, 1150 ppm fluoride as NaF); a reference dentifrice (RD, disodium pyrophosphate + 1100 ppm fluoride as NaF) or a negative control dentifrice (NC, fluoride-free) in a randomised, double-blind, crossover design. Specimens were removed at 2, 4 and 8 h post-brushing and exposed to an ex vivo acid challenge. Surface microhardness (Knoop) was measured at each stage. The primary efficacy variable was relative erosion resistance (RER); other variables included the surface microhardness recovery (SMHR), acid resistance ratio (ARR) and enamel fluoride uptake (EFU).ResultsAfter 4 h, the results for RER, ARR and EFU were in the order PC > TD = RD > NC with PC > TD = RD = NC for SMHR. Results at 2 and 8 h were generally consistent with the 4 h data. Mineralisation progressed over time. Dentifrices were generally well-tolerated.ConclusionsIn this in situ model, addition of phytate or pyrophosphate to a fluoride dentifrice inhibited the remineralising effect of fluoride. Both formulations still delivered fluoride to the enamel and inhibited demineralisation, albeit to a lesser extent than a polyphosphate-free dentifrice.Clinical relevanceAddition of phytate or pyrophosphate to a fluoride dentifrice may reduce its net anti-erosive properties.

The Sidi Ifni transect across the rifted margin of Morocco (Central Atlantic): Vertical movements constrained by low-temperature thermochronology

The occurrence of km-scale exhumations during syn- and post-rift stages has been documented along Atlantic continental margins, which are also characterised by basins undergoing substantial subsidence. The relationship between the exhuming and subsiding domains is poorly understood. In this study, we reconstruct the evolution of a 50 km long transect across the Moroccan rifted margin from the western Anti-Atlas to the Atlantic basin offshore the city of Sidi Ifni. Low-temperature thermochronology data from the Sidi Ifni area document a ca. 8 km exhumation between the Permian and the Early/Middle Jurassic. The related erosion fed sediments to the subsiding Mesozoic basin to the NW. Basement rocks along the transect were subsequently buried by 1–2 km between the Late Jurassic and the Early Cretaceous. From late Early/Late Cretaceous onwards, rocks present along the transect were exhumed to their present-day position.

Lower Badenian coarse-grained Gilbert deltas in the southern margin of the Western Carpathian Foredeep basin

AbstractTwo coarse-grained Gilbert-type deltas in the Lower Badenian deposits along the southern margin of the Western Carpathian Foredeep (peripheral foreland basin) were newly interpreted. Facies characterizing a range of depositional processes are assigned to four facies associations — topset, foreset, bottomset and offshore marine pelagic deposits. The evidence of Gilbert deltas within open marine deposits reflects the formation of a basin with relatively steep margins connected with a relative sea level fall, erosion and incision. Formation, progradation and aggradation of the thick coarse-grained Gilbert delta piles generally indicate a dramatic increase of sediment supply from the hinterland, followed by both relatively continuous sediment delivery and an increase in accommodation space. Deltaic deposition is terminated by relatively rapid and extended drowning and is explained as a transgressive event. The lower Gilbert delta was significantly larger, more areally extended and reveals a more complicated stratigraphic architecture than the upper one. Its basal surface represents a sequence boundary and occurs around the Karpatian/Badenian stratigraphic limit. Two coeval deltaic branches were recognized in the lower delta with partly different stratigraphic arrangements. This different stratigraphic architecture is mostly explained by variations in the sediment delivery and /or predisposed paleotopography and paleobathymetry of the basin floor. The upper delta was recognized only in a restricted area. Its basal surface represents a sequence boundary probably reflecting a higher order cycle of a relative sea level rise and fall within the Lower Badenian. Evidence of two laterally and stratigraphically separated coarse-grained Gilbert deltas indicates two regional/basin wide transgressive/regressive cycles, but not necessarily of the same order. Provenance analysis reveals similar sources of both deltas. Several partial source areas were identified (Mesozoic carbonates of the Northern Calcareous Alps and the Western Carpathians, crystalline rocks of the eastern margin of the Bohemian Massif, older sedimentary infill of the Carpathian Foredeep and/or the North Alpine Foreland Basin, sedimentary rocks of the Western Carpathian/Alpine Flysch Zone).

Wear and Oxidation Behaviour of Tungsten Carbide Based Coatings: A Review

Failure of components under severe environment caused by the diversity of wear mechanisms and oxidation necessitated to understand, which is fundamental to estimate durability and reliability of coatings. Abrasive and erosion wear contributed to the maximum failure rate encountered in real life situations. In high-temperature applications, oxidation leads to deterioration in desired properties which causes premature failure of machine or system components. Tungsten carbide (WC) based coatings serve with both types of wears and furthermore deals with high-temperature serviceability. Among the pure metals tungsten exhibits uppermost relative abrasive and erosion resistance which provides the base for utilization of WC based coatings for severe wear applications. The emphasis of this review is on wear and oxidation performance of tungsten carbide based coatings developed by different thermal spray techniques.

Status Assessment of Agricultural Drainage Ditches

Abstract. Poor maintenance, environmental concerns, land use changes, and adaptation to climate change are creating a growing need for better agricultural drainage. The objectives of this study were to identify ditch properties that can be evaluated visually on-site and related soil erosion processes, and to define parameters requiring more intensive study and estimate these using simplified methods. The study included surveys of ditches in various soils using MADRAS (Minnesota Agricultural Ditch Research Assessment for Stability) to classify ditch status. To explain why some ditch segments were in poor condition, additional field and laboratory studies were carried out. Soil samples were taken for analysis of particle size distribution, unsaturated direct shear strength, and critical stress for erosion. The HEC-RAS data model was used for simulation of hydraulic forces acting at different flow rates. Digital maps of land use in the catchment area in different years were used to estimate changes in runoff conditions over time. MADRAS proved to be a suitable tool for rapid assessment of stability problems in ditches. The HEC-RAS simulations were a good complement to MADRAS in assessing how changes in land use affected the hydraulic load and in highlighting bottlenecks in the system. However, the hydraulic load did not adequately explain the degree of degradation in some ditch segments. Measurements of soil shear strength were a good aid to understanding existing degradation. Thus, assessment of soil erodibility and bank stability is essential in anticipating the risk of future erosion processes in ditches. Keywords: Cohesive strength meter, HEC-RAS, MADRAS, Unsaturated direct shear strength.

Improving the utility of erosion pins: absolute value of pin height change as an indicator of relative erosion

Erosion pins can be an inexpensive and intuitive method to estimate hillslope soil erosion and deposition. It is common practice to calculate annual erosion/deposition rates (also called ground advance/retreat or ground lowering) from pin measurements as the mean net change in pin height over a given area. However, many studies have found this net ‘real number’ change does not produce strong relationships with erosion rates estimated using other methods, or with variables expected to be highly correlated with erosion, calling into question the efficacy of this approach. Here we evaluate an alternative (or complementary) approach - using the absolute value of pin height change to capture the overall magnitude of soil movement as an indicator of erosion. We used measurements from erosion pins in experimental plots across different maize-bean production systems and forest-fallows in northern El Salvador to compare both the absolute and ‘real number’ change in erosion pin height against modeled erosion, related factors (e.g., slope and soil cover), and soil loss collected in erosion pits. We found that the absolute value of pin height change was strongly correlated (r=0.67, p<0.01) with erosion rates predicted from the Revised Universal Soil Loss Equations (RUSLE) and moderately correlated (r=0.82, p<0.10) with erosion measured in collection pits, while no relationships were found for the real number value. The absolute value was also strongly correlated with RUSLE factors related to slope and cover, while no correlations existed for the real number value. Statistically significant differences in RUSLE-predicted erosion were found between plots classified as having ‘high’, ‘medium’ and ‘low’ vegetative cover, and these differences were also detected using absolute value of pin height change. Conversely, such differences were not detected using the net real number value. We conclude that, when using erosion pins for comparative analysis between land management practices or monitoring changes in erosion over time, the absolute value of pin height change is likely a better indicator than net real number change. We encourage additional research using new and existing datasets to further evaluate the utility of absolute value of pin height change as an indicator of relative erosion.

Evaluating the WEPP Rangeland Hillslope Model Using Cesium‐137 Estimated Spatial Erosion Data

Core Ideas WEPP rangeland model was evaluated using spatial erosion data for the first time. WEPP and 137Cs methods predicted similar low soil erosion rates. Spatial erosion patterns predicted by WEPP and 137Cs methods agreed well. WEPP predicted soil erosion patterns well along rangeland hillslopes. Lack of spatially distributed soil erosion data has greatly hampered the development and improvement of process‐based soil erosion models. The 137Cs method has been widely used to estimate soil erosion and redistribution but has seldom been used to evaluate process‐based erosion models. This study evaluated spatial erosion patterns predicted by the Water Erosion Prediction Project (WEPP) model using 137Cs‐estimated spatially distributed erosion data and quantified the effects of slope length on erosion along rangeland hillslopes. Eight rangeland hillslopes in midwestern Oklahoma were selected. The WEPP rangeland model was parameterized with observed soil and vegetation data. One downslope transect was sampled for each hillslope. At each sampling position, seven samples along a contour line were composited to represent the 137Cs inventory for that slope position to reduce random spatial variation. Both methods predicted low soil erosion rates, with the maximum erosion rates being near 2 Mg ha−1 yr−1. The erosion rates predicted by the two methods were significantly correlated at P = 0.01, and the medians were not significantly different; however, a paired t‐test showed that WEPP predicted significantly lower erosion rates than the 137Cs method. More importantly, the WEPP‐predicted soil erosion patterns in response to slope length agreed very well with those predicted by the 137Cs method. The loci of the maximum and minimum erosion rates were similar between the two methods for seven transects. The WEPP rangeland model predictions for the spatial patterns of relative soil erosion intensity along a hillslope compared favorably with 137Cs method estimates.

General Aspects of the Multilateral Instrument

The Multilateral Instrument (MLI) can be regarded as the most innovative and far-reaching development in the area in the area of tax treaties in recent decades. The implementation of the tax treaty related Base Erosions and Profit Shifting (BEPS) measures through the MLI will have major consequences for the global network of bilateral tax treaties. The actual impact of the MLI on tax treaties depends to a large extent on the choices and reservations made by each participating state, especially with regard to provisions that do not reflect BEPS minimum standards. These positions will also influence the impact of the MLI for each state’s participating treaty partners. This article examines certain general and procedural aspects of the MLI, including the scope and interpretation of the MLI. This is followed by a discussion of the operation and legal consequences of the compatibility clauses, the reservations and the notification obligations. The focus is then shifted to various procedural aspects related to the final provisions of the MLI, including the entry into effect and timing aspects.

CFD investigation of the erosion severity in 3D flow elbow during crude Oil contaminated sand transportation

During upstream petroleum production operations, crude oil and sand eroded from formation zones are often transported as a mixture through pipes up to the well heads and between well heads and flow stations. The sand particles are carried by the flow momentum in streamlines that impinge the pipe walls, in particular at the elbows, resulting in seriously erosive damages. This can lead to a disastrous and costly failure in the system. Therefore, computing of erosion rate during the system operation is indispensable for predicting any potential failure in advance, and hence avoid it. Among all the fittings employed in piping systems, elbows are the most likely subjected to erosion resulting from sand particles carried with oil, where those particles deviate from the mainstream and impact the walls while passing through the bended section of elbows. To reduce the erosive damage produced by the solid particles, a numerical simulation based erosion prediction model has been employed to compute the relative erosion severity. In this study ,the potentials required to simulate the current problem comprehensively, various physical aspects have been combined together including flow turbulence, particle tracking, and erosion simulation. In addition to the comprehensive insights offered by the computational simulation of crude oil flow, high costs along with tedious efforts required for traditional experimentations can be avoided. The current analysis offers priceless physical insight towards serve this model as an alternative sand management tool, and can be used to quantify oil recovery. Furthermore, it can identify limiting steps and components; form a computer-aided tool for designing and optimizing the future pipe systems in order to enhance their lifetime through improving their erosion resistance, which is definitely will save considerable amount of time and cost.

Exotic clasts, debris flow deposits and their significance for reconstruction of the Istebna Formation (Late Cretaceous – Paleocene, Silesian Basin, Outer Carpathians)

AbstractThe different types of calcareous exotic clasts (fragments of pre-existing rocks), embedded in the Paleocene siliciclastic deposits of the Istebna Formation from the Beskid Mały Mountains (Silesian Unit, Western Outer Carpathians), were studied and differentiated through microfacies-biostratigraphical analysis. Calcareous exotics of the Oxfordian- Kimmeridgian age prevail, representing a type of sedimentation comparable to that one documented for the northern Tethyan margin. The Tithonian exotic clasts (Štramberk-type limestones), which are much less common, were formed on a carbonate platform and related slope. The sedimentary paleotransport directions indicate the Silesian Ridge as a main source area for all exotics, which were emplaced in the depositional setting of the flysch deposits. The exotics constitute a relatively rare local component of some debrites. Proceedings of the sedimentological facies analysis indicate that these mass transport deposits were accumulated en-masse by debris flows in a deep-water depositional system in the form of a slope apron. Exotics prove that clasts of the crystalline basement and, less common, fragments of the sedimentary cover, originated from long-lasting tectonic activity and intense uplift of the source area. Mass transport processes and mass accumulation of significant amounts of the coarse-grained detrital material in the south facial zone of the Silesian Basin during the Early Paleogene was due to reactivation of the Silesian Ridge and its increased denudation. Relative regression and erosion of the emerged older flysch deposits were also forced by this uplift. These processes were connected with the renewed diastrophic activity in the Alpine Tethys.

Structure and characteristics of functional powder composite materials obtained by spark plasma sintering

The article describes the results of spark plasma sintering of ceramic materials based on titanium carbide, titanium carbosilicide, ceramic composite materials based on zirconium oxide, strengthened by carbon nanostructures and composite materials of electrotechnical purpose based on copper with addition of carbon structures and titanium carbosilicide. The research shows that the spark plasma sintering can achieve relative density of the material up to 98%. The effect of sintering temperature on the phase composition, density and porosity of the final product has been studied. It was found that with addition of carbon nanostructures the relative density and hardness decrease, but the fracture strength of ZrO2 increases up to times 2. The relative erosion resistance of the electrodes made of composite copper-based powder materials, obtained by spark plasma sintering during electroerosion treatment of tool steel exceeds that parameter of pure copper up to times 15.