Flux Of Matter Research Articles

Geochemistry of Neoproterozoic Nagod Limestones from the Girgita Mine, Bhander Group, Madhya Pradesh, India

Vindhyan limestone of the Bander Group (Late Neoproterozoic) in the Maihar area, Satna district, is a part of an anticlinal fold and it forms an outlier in the study area. Geochemical analysis reveals that the proportion of Rare Earth Elements (REEs; La-Lu) in limestones varies between 14.8 ppm and 49.5 ppm. The Eu and Ce anomalies (normalized against Post Archean Australian Shale; PAAS) range from ~ 0.53 to 0.69 and ~ 0.57 to 1.07, respectively. The results of this study revealed that the limestones were principally controlled by the admixture of detrital materials, i.e., (i) The low values of REEs (ii) high values of Y/Ho (iii) positive correlation between REEs and Si, Al, Ti, V, Co, Ni, and Nb, and (iv) slightly negative correlation between CaO and REEs. Further, the variations in Ce anomaly may be due to the influx of detrital materials and positive Ce anomaly was attributable to the shallow marine depositional condition. The distribution of REEs (Chondrite normalized values) illustrates different patterns in the Nagod limestone due to the degree of differentiation in terms of LREEs and HREEs and Eu anomaly. The variations in elemental concentrations and the REE patterns revealed the mixing of detrital materials in the Nagod limestones.

Reconstructing a 51-year record of catchment scale dissolved load for the Haast/Awarua River in the Southern Alps, New Zealand

Mountains dominate global denudation fluxes of solutes to the oceans despite being only a modest portion of the Earth's surface. Determining the flux of material exhumed from mountains as dissolved load, however, requires careful measurement of ionic concentrations and discharge that may be hard to obtain. We reconstruct the dissolved load and total dissolved solids yield from pre-existing discharge measurements and 32-years on monthly water quality sampling in a headwater catchment in the Southern Alps/Ka Tiritiri o te Moana, New Zealand. The dissolved weathering yield of the Haast/Awarua River for 1971–2020 was 218 ± 48 t km−2 a−1. The flux of dissolved material from the mountain catchment has a seasonal signal, with higher TDS concentrations during winter, but greater chemical weathering yields during summer. Hydrographic behaviour is an important control of weathering yields with 70 % of dissolved load being transported during event flow. Variations in chemical weathering yields are sensitive to changes in stream flow associated with broader climate oscillations, which will have a direct effect on estimations of chemical weathering rates since dissolved flux is strongly correlated to changes in stream flow.

Lunar collision rate with primordial black holes

ABSTRACT A recent letter studied cratering during collisions between rocky bodies and primordial black holes. Hydrodynamic simulations in that work showed that ejecta blankets from these collisions are steeper because the black holes completely penetrate the target, potentially making these craters distinguishable from traditional point-like impactors. This may allow us to use lunar craters to constrain primordial black holes in the asteroid-mass window, about 1017–1019 g. In this work, we calculate the lunar dark matter flux from the Galactic halo and several models for a dark disc. We consider several effects that may enhance the dark matter flux, such as gravitational focusing on the Solar system and historical modulations due to the Solar system’s galactic orbit. We find that non-detection of novel craters on the Moon can constrain relativistic compact MACHO dark matter up to 1017 g at 95 per cent confidence, motivating a detailed search through lunar surface scans. In addition, we show that fluxes near Earth from dark discs may be significantly enhanced by gravitational focusing and that the relative velocity between the disc and the Sun can result in annual modulations out of phase with the annual modulations from the halo.

The Impact of Sea Ice Cover on Microbial Communities in Antarctic Shelf Sediments.

The area around the Antarctic Peninsula (AP) is facing rapid climatic and environmental changes, with so far unknown impacts on the benthic microbial communities of the continental shelves. In this study, we investigated the impact of contrasting sea ice cover on microbial community compositions in surface sediments from five stations along the eastern shelf of the AP using 16S ribosomal RNA (rRNA) gene sequencing. Redox conditions in sediments with long ice-free periods are characterized by a prevailing ferruginous zone, whereas a comparatively broad upper oxic zone is present at the heavily ice-covered station. Low ice cover stations were highly dominated by microbial communities of Desulfobacterota (mostly Sva1033, Desulfobacteria, and Desulfobulbia), Myxococcota, and Sva0485, whereas Gammaproteobacteria, Alphaproteobacteria, Bacteroidota, and NB1-j prevail at the heavy ice cover station. In the ferruginous zone, Sva1033 was the dominant member of Desulfuromonadales for all stations and, along with eleven other taxa, showed significant positive correlations with dissolved Fe concentrations, suggesting a significant role in iron reduction or an ecological relationship with iron reducers. Our results indicate that sea ice cover and its effect on organic carbon fluxes are the major drivers for changes in benthic microbial communities, favoring potential iron reducers at stations with increased organic matter fluxes.

Synthesis of zirconium boride (ZrB2) rod crystals through salt-assisted boro/carbothermal reduction

High-aspect-ratio ZrB2 rod crystals were synthesized via a molten-salt-mediated boro/carbothermal reduction using ZrOCl2· 8H2O/B4C/C as the raw material and NaCl as the flux material. This synthesis may improve the poor fracture toughness of monolithic ZrB2 ceramics. X-ray diffraction and scanning electron microscopy confirmed that the heat-treatment temperature of 1550 °C and the addition of 50 wt% NaCl were the most effective in the preparation of ZrB2 grains with a high aspect ratio. Thermogravimetric and differential scanning calorimetry was used to study the influence of NaCl addition, which increased the liquid-phase content. Finally, the growth of ZrB2 grains along the c-axis into rod-like morphology at elevated temperatures was investigated by transmission electron microscopy. This work revealed that the addition of NaCl has a positive effect on the reducing of synthesis temperature and increasing of products particle size. The ZrB2 rod crystals synthesized have diameters and aspect ratios of approximately 1 μm and 30, respectively.

Control mechanisms of Os isotope anomalies of Co-rich crusts from the Line and Marcus–Wake seamounts areas

The evolution curve of the Os isotopic composition (187Os/188Os) of Co-rich ferromanganese crusts reflects the correlation between the supply of continental and mantle-derived materials to seawater in different growth periods of the crusts. In general, a certain ratio of the supply of these materials to the ocean is maintained based on the input–output law. This means that the evolution curves of the Os isotopic composition of crusts in different growth periods can be compared with that of seawater in the Central and Western Pacific Ocean. However, the Os isotopic composition of crusts from the Line and Marcus–Wake seamounts areas is anomalous before 40 Ma and after 7 Ma, respectively, with the ratio being higher than that of seawater, respectively. Throughout the long growth history of the crusts, continental denudation materials entering the marine system through monsoons and atmospheric circulation have been important sources of terrigenous materials in the metallogenetic process. Variations in the contents of indicator elements, such as Si and Al, reflect the input flux of terrigenous materials. During growth periods of the crusts, seamounts they located successively entered the influencing range of the southeast trade wind and westerlies owing to plate tectonics. Depending on the evolution of the atmospheric circulation system, the supply of terrigenous materials to the crusts changes in different seamount areas. The supply of aeolian dust from the Americas and Eurasia may be the dominant factor causing the Os isotope anomalies of the crusts. However, further paleoceanographic studies at the tectonic scale are required to understand the anomalies and enrichment of elements during the metallogenetic process of the crusts. Overall, increased supply of terrigenous materials, along with the evolution of the paleoceanographic environment, may promote the growth rate of the crusts.

Kimberlite eruptions driven by slab flux and subduction angle

Kimberlites are sourced from thermochemical upwellings which can transport diamonds to the surface of the crust. The majority of kimberlites preserved at the Earth’s surface erupted between 250 and 50 million years ago, and have been attributed to changes in plate velocity or mantle plumes. However, these mechanisms fail to explain the presence of strong subduction signatures observed in some Cretaceous kimberlites. This raises the question whether there is a subduction process that unifies our understanding of the timing of kimberlite eruptions. We develop a novel formulation for calculating subduction angle based on trench migration, convergence rate, slab thickness and density to connect the influx of slab material into the mantle with the timing of kimberlite eruptions. We find that subduction angles combined with peaks in slab flux predict pulses of kimberlite eruptions. High rates of subducting slab material trigger mantle return flow that stimulates fertile reservoirs in the mantle. These convective instabilities transport slab-influenced melt to the surface at a distance inbound from the trench corresponding to the subduction angle. Our deep-time slab dip formulation has numerous potential applications including modelling the deep carbon and water cycles, and an improved understanding of subduction-related mineral deposits.

Enhanced mesopelagic particle export in the northern South China Sea derived from 210Po/210Pb disequilibrium

Vertical distributions of dissolved and particulate 210Po and 210Pb in the water column were examined along three transects occupied on July 2016 in the northern South China Sea (SCS) to investigate particle dynamics and export. In the mixed layer, 210Po was deficient with respect to 210Pb with a 210Po/210Pb activity ratio of 0.08–0.57 and an average of 0.31 ± 0.12. The 210Po/210Pb ratio increased to 0.39–0.96 with an average of 0.71 ± 0.16 at the base of the euphotic layer (100 m). 210Po was largely depleted relative to 210Pb again in the mesopelagic layer (100–1000 m). The activity ratio of 210Po/210Pb ranged from 0.12 to 1.04 with an average of 0.42 ± 0.20, suggesting an intensified particle scavenging. Meanwhile, the residence time of particulate 210Po (PPo) in the mesopelagic layer varied from 0.01 to 0.47 yr with an average of 0.11 ± 0.02 yr, also indicating the fast removal of particles. Both the disequilibrium between 210Po and 210Pb and the short residence time of PPo in the mesopelagic water indicated a stronger scavenging and subsequent removal of 210Po relative to 210Pb throughout the water column. Based on the observed 210Po deficit, the export flux of 210Po in the mesopelagic layer was estimated in the range of 96–625 dpm m−2 d−1 with an average of 382 ± 16 dpm m−2 d−1, which was an order of magnitude higher than that in the euphotic layer. Furthermore, the export flux of total particulate matter (TPM) in mesopelagic layer was estimated between 2.15 and 30.18 g m−2 d−1. Comparing to the TPM export flux in the euphotic layer (0.44–2.67 g m−2 d−1), the significantly elevated TPM export flux in the mesopelagic waters may require extra supply of particles in addition to sinking particles from the upper water column, which is likely sourced from the surrounding shelves in the northern SCS.

The effect of weld groove variations on the toughness of welding joints of AISI 1050 material

SMAW (Shielded Metal Arc Welding) welding is a metal joining process that uses heat energy to melt the workpiece and electrode (fill material). The flux material used for type E7016, a low hydrogen electrode wire typically used for welding heavy-duty plates and structures. Its use is for welding medium carbon steel, bridges, ships and machinery. The result of welding electrode E7016 is very smooth, deep penetration, crack resistant, ductile, good weld appearance and stable arc, the material used in the SMAW welding process is AISI 1050 steel. While AISI 1050 steel is steel that has a carbon content of 0.50 % so that it is classified as medium carbon steel. This steel is widely used in the market because it has many advantages, one of which is as an automotive component. This steel has the characteristics of good machinability, good wear resistance and medium mechanical properties. This study aims to determine the shock strength (impact) and the difference in the time of making weld grooves on SMAW welding results on AISI 1050 steel with variations of Double Bevel and Double V Groove grooves. In testing in the Weld Metal area with a current used of 110 Ampere. From the tests that have been carried out, it is known that the value of the highest impact strength is in the Double Bevel groove which has a value of 1.91 Joule/mm2, for the manufacture of welded grooves where the Double Bevel time is shorter than Double V Groove, so the time produced by Double Bevel which is 3.44 minutes/second.

Large-scale nutrient and carbon dynamics along the river-estuary-ocean continuum

Nutrient and carbon dynamics within the river-estuary-coastal water systems are key processes in understanding the flux of matter from the terrestrial environment to the ocean. Here, we analysed those dynamics by following a sampling approach based on the travel time of water and an advanced calculation of nutrient fluxes in the tidal part. We started with a nearly Lagrangian sampling of the river (River Elbe, Germany; 580 km within 8 days). After a subsequent investigation of the estuary, we followed the plume of the river by raster sampling the German Bight (North Sea) using three ships simultaneously. In the river, we detected intensive longitudinal growth of phytoplankton connected with high oxygen saturation and pH values and an undersaturation of CO2, whereas concentrations of dissolved nutrients declined. In the estuary, the Elbe shifted from an autotrophic to a heterotrophic system: Phytoplankton died off upstream of the salinity gradient, causing minima in oxygen saturation and pH, supersaturation of CO2, and a release of nutrients. In the shelf region, phytoplankton and nutrient concentrations were low, oxygen was close to saturation, and pH was within a typical marine range. Over all sections, oxygen saturation was positively related to pH and negatively to pCO2. Corresponding to the significant particulated nutrient flux via phytoplankton, flux rates of dissolved nutrients from river into estuary were low and determined by depleted concentrations. In contrast, fluxes from the estuary to the coastal waters were higher and the pattern was determined by tidal current. Overall, the approach is appropriate to better understand land-ocean fluxes, particularly to illuminate the importance of these fluxes under different seasonal and hydrological conditions, including flood and drought events.

Large mass inflow rates in Saturn’s rings due to ballistic transport and mass loading

The Cassini mission provided key measurements needed to determine the absolute age of Saturn’s rings, including the extrinsic micrometeoroid flux at Saturn, the volume fraction of non-icy pollutants in the rings, and the total ring mass. These three factors constrain the ring age to be no more than a few 100 Myr (Kempf et al., 2022). Observations during the Cassini Grand Finale also showed that the rings are losing mass to the planet at a prodigious rate. Some of the mass flux falls as “ring rain” at high latitudes. However, the influx in ring rain is considerably less than the total measured mass influx of 4800 to 45000 kg s−1 at lower latitudes (Waite et al., 2018).In addition to polluting the rings, micrometeoroid impacts lead to ballistic transport, the mass and angular momentum transport due to net exchanges of meteoroid impact ejecta. Because the ejecta are predominantly prograde, they carry net angular momentum outward. As a result, ring material drifts inward toward the planet. Here, for the first time, we use a simple model to quantify this radial mass inflow rate for dense rings and find that, for plausible choices of parameters, ballistic transport and mass loading by meteoroids can produce a total inward flux of material in the inner B ring and in the C ring that is on the order of a few ⋅103 to a few ⋅104 kg s−1, in agreement with measurements during the Cassini Grand Finale. From these mass inflow rates, we estimate that the remaining ring lifetime is ∼ 15 to 400 Myr. Combining this with a revised pollution age of ∼ 120 Myr, we conclude that Saturn’s rings are not only young but ephemeral and probably started their evolution on a similar timescale to their pollution age with an initial mass of one to a few Mimas masses.In addition to showing that meteoroid impacts can produce a large sustained mass inflow through the B and C rings, this paper addresses various uncertainties and considers possible contributions by additional transport mechanisms and by external torques. We also map out a set of future research projects, including global simulations.

Ant nests effect on organic matter, carbon, and nitrogen flux in the soil under grasses tufts in Lamto savannah (Côte d'Ivoire)

AbstractAnts are known to contribute to the physical and chemical improvement of the soil. In this context, the hypothesis put forward is that ants improve the nitrogen (N) supplementation necessary to ensure the high primary production measured in the Lamto savannah. Recent investigations in the humid savannah ecosystem showed that ant nests’ association with perennial grasses enhances their growth, productivity, and microorganism activity. This study aimed at understanding the effect of ant nests on organic matter (OM), carbon (C), and N flux beneath grass tufts. Under each grass tuft chosen to carry out this study, soil samples were taken from the depths of 0–10 cm using an auger at shrubby, clear grassy, and transitional grassy savannah. The analytical method by incineration of the loss on fire was used to determine the OM amount. The Kjeldahl method was used to determine the total N amount in the soil under grass tufts. The results showed that these components’ amount is higher beneath grass tufts associated with ant nests than those not associated with ant nests. The presence of ant nests increases OM and C amount in the soil under Hyparrhenia diplandra tufts than Andropogon schirensis, and Loudetia simplex tufts. In contrast, N amount is higher under L. simplex tufts than A. schirensis; but mean under H. diplandra. The carbon/nitrogen ratios less than 10 indicate high OM mineralization under grass tufts associated with ant nests. This provides the plants with an adequate supply of nutrients.

Remnants of magma underplating by the Emeishan mantle plume within the lithosphere beneath southeastern margin of the Tibetan Plateau

The Emeishan Large Igneous Province (ELIP) is located along southeastern margin of the Tibetan Plateau, where long-wavelength crustal thickening and surface uplift have been attributed to the influx of weak crustal material from central Tibet into the lower crust beneath the Yangtze Craton. We have developed a new shear-wave velocity model for the lithosphere beneath eastern Tibet, based on a two-step linearized joint inversion technique of P-wave receiver functions (PRFs) with Rayleigh wave dispersion (10–60 s period) and Love wave dispersions (8–30 s period) for three dense seismic arrays. We applied bootstrap resampling technique to calculate the results of inversion. The resulting shear velocity model revealed two major low-velocity features in the middle–lower crust beneath southeastern Tibet. The horizontally extensive low-velocity zone (LVZ) beneath the northern Sichuan–Yunnan diamond-shaped block (SYDSB) can be interpreted as possible lower crustal flow from central Tibet, whereas the low-velocity anomaly observed beneath the Xiaojiang Fault is consistent with the presence of a partially molten layer enhanced by shear deformation along large faults. These two LVZs are separated by a lithospheric-scale high-velocity zone (HVZ) that is situated beneath the geologically inferred core of the ELIP. Based on other geophysical and geological evidence, we interpret this high-velocity anomaly body as remnants of the Emeishan plume-strengthened lithosphere that originally formed during the Permian volcanism, and we speculate that it has acted as a barrier to the hypothesized flow of lower crustal material from central Tibet since the late Cenozoic.

Different Magmatic‐Hydrothermal Fluids at the Same Magma Source Support Distinct Microbial Communities: Evidence From In Situ Detection

AbstractSubmarine magmatic‐hydrothermal systems are dominated by volcanism and generate unique biocenoses. However, the relationships between the microbial communities and the broad range of chemical and physical variability within the systems are poorly understood. Here, a high‐precision in situ Raman quantitative technique was used for the hydrothermal fluids at the Onsen site and a newly found site named Faxian in a magmatic‐hydrothermal system at the DESMOS caldera, Manus back‐arc basin. The maximum in situ H2 concentration (8.56 mmol/kg) at the Onsen site is the highest value ever reported in similar hydrothermal systems. In contrast, the diffuse fluid at the Faxian site was characterized by rich H2S (7.78 mmol/kg) but without H2. The differences in mixing contents of seawater induced different geochemical reactions and fluxes of hydrogen and hydrogen sulfide. Furthermore, the existence of hydrogen‐ and sulfide‐oxidizing genes suggests that the oxidation of hydrogen and hydrogen sulfide are the energy sources of the microbial communities at the two sites even within the same magma source. The in situ quantitative analyses of different types of fluids provide implications on the materials fluxes in the magmatic‐hydrothermal system, and the relationships between widespread submarine volcanic activities and life in early Earth.

A control volume finite-element model for predicting the morphology of cohesive-frictional debris flow deposits

Abstract. To predict the morphology of debris flow deposits, a control volume finite-element model (CVFEM) is proposed, balancing material fluxes over irregular control volumes. Locally, the magnitude of these fluxes is taken proportional to the difference between the surface slope and a critical slope, dependent on the thickness of the flow layer. For the critical slope, a Mohr–Coulomb (cohesive-frictional) constitutive relation is assumed, combining a yield stress with a friction angle. To verify the proposed framework, the CVFEM numerical algorithm is first applied to idealized geometries, for which analytical solutions are available. The Mohr–Coulomb constitutive relation is then checked against debris flow deposit profiles measured in the field. Finally, CVFEM simulations are compared with laboratory experiments for various complex geometries, including canyon–plain and canyon–valley transitions. The results demonstrate the capability of the proposed model and clarify the influence of friction angle and yield stress on deposit morphology. Features shared by the field, laboratory, and simulation results include the formation of steep snouts along lobe margins.

Structure and composition of natural ferrihydrite nano-colloids in anoxic groundwater

Fe-rich mobile colloids play vital yet poorly understood roles in the biogeochemical cycling of Fe in groundwater by influencing organic matter (OM) preservation and fluxes of Fe, OM, and other essential (micro-)nutrients. Yet, few studies have provided molecular detail on the structures and compositions of Fe-rich mobile colloids and factors controlling their persistence in natural groundwater. Here, we provide comprehensive new information on the sizes, molecular structures, and compositions of Fe-rich mobile colloids that accounted for up to 72% of aqueous Fe in anoxic groundwater from a redox-active floodplain. The mobile colloids are multi-phase assemblages consisting of Si-coated ferrihydrite nanoparticles and Fe(II)-OM complexes. Ferrihydrite nanoparticles persisted under both oxic and anoxic conditions, which we attribute to passivation by Si and OM. These findings suggest that mobile Fe-rich colloids generated in floodplains can persist during transport through redox-variable soils and could be discharged to surface waters. These results shed new light on their potential to transport Fe, OM, and nutrients across terrestrial-aquatic interfaces.

A Dissipative Reaction Network Drives Transient Solid–Liquid and Liquid–Liquid Phase Cycling of Nanoparticles

AbstractTransient states maintained by energy dissipation are an essential feature of dynamic systems where structures and functions are regulated by fluxes of energy and matter through chemical reaction networks. Perfected in biology, chemically fueled dissipative networks incorporating nanoscale components allow the unique properties of nanomaterials to be bestowed with spatiotemporal adaptability and chemical responsiveness. We report the transient dispersion of gold nanoparticles in water, powered by dissipation of a chemical fuel. A dispersed state that is generated under non‐equilibrium conditions permits fully reversible solid–liquid or liquid–liquid phase transfer. The molecular basis of the out‐of‐equilibrium process is reversible covalent modification of nanoparticle‐bound ligands by a simple inorganic activator. Activator consumption by a coupled dissipative reaction network leads to autonomous cycling between phases. The out‐of‐equilibrium lifetime is tunable by adjusting the pH value, and reversible phase cycling is reproducible over several cycles.

A Dissipative Reaction Network Drives Transient Solid-Liquid and Liquid-Liquid Phase Cycling of Nanoparticles.

Transient states maintained by energy dissipation are an essential feature of dynamic systems where structures and functions are regulated by fluxes of energy and matter through chemical reaction networks. Perfected in biology, chemically fueled dissipative networks incorporating nanoscale components allow the unique properties of nanomaterials to be bestowed with spatiotemporal adaptability and chemical responsiveness. We report the transient dispersion of gold nanoparticles in water, powered by dissipation of a chemical fuel. A dispersed state that is generated under non-equilibrium conditions permits fully reversible solid-liquid or liquid-liquid phase transfer. The molecular basis of the out-of-equilibrium process is reversible covalent modification of nanoparticle-bound ligands by a simple inorganic activator. Activator consumption by a coupled dissipative reaction network leads to autonomous cycling between phases. The out-of-equilibrium lifetime is tunable by adjusting the pH value, and reversible phase cycling is reproducible over several cycles.

Biogeochemical River Runoff Drives Intense Coastal Arctic Ocean CO2 Outgassing

AbstractArctic warming alters land‐to‐sea fluxes of nutrients and organic matter, which impact air‐sea carbon exchange. Here we use an ocean‐biogeochemical model of the southeastern Beaufort Sea (SBS) to investigate the role of Mackenzie River biogeochemical discharge in modulating air‐sea CO2 fluxes during 2000–2019. The contribution of six biogeochemical discharge constituents leads to a net CO2 outgassing of 0.13 TgC yr−1, with a decrease in the coastal SBS carbon sink of 0.23 and 0.4 TgC yr−1 due to riverine dissolved organic and inorganic carbon, respectively. Years with high (low) discharge promote more CO2 outgassing (uptake) from the river plume. These results demonstrate that the Mackenzie River modulates the capacity of the SBS to act as a sink or source of atmospheric CO2. Our work suggests that accurate model representation of land‐to‐sea biogeochemical coupling can be critical for assessing present‐day Arctic coastal ocean response to the rapidly changing environment.

Causes and mechanisms of the disappearance of braided channel patterns (the example of the Białka River, Western Carpathians)

The channels of multi-threaded (braided) rivers occur commonly in areas that fulfill certain conditions such as substantial influx of bed material and gradients large enough to create significant energy of flowing water. Natural conditions favoring the formation of multithreaded channels are present in the Carpathians in Poland in Podhale – a large basin located in the piedmont area of the high-mountain Tatra massif. The area had experienced glaciation in the Pleistocene. Yet the 20th century – and especially its second half – was a period of rapid and irreversible elimination of braided channels across the region. The Białka is considered to be the last braided river in the Carpathians in Poland. Many parameters like: structure (morphologic reach sequence), degree of braiding (BI index, W/D) and also a number of hydrodynamic ones (unit stream power, critical stress, shear stress, others) were investigated in order to assess a current stage of development of the Białka river channel. The Białka river channel appears to be a complex system with a differentiated structure. Its channel system is a mosaic of different types described by the following sequence: straight-sinuous-braided. It represents an intermediate type that is somewhere between a single- and a multi-threaded channel. Future evolution of the Białka river channel appears to include further degradation and transformation into a poorer channel ecosystem.