Hydrodynamic parameters in a flood impacted boulder block ramp: Krzczonówka mountain stream,Polish Carpathians

Boulder block ramps are river engineering structures used to stabilise river beds. Block ramps provide a semi-natural and aesthetically pleasing solution to certain river engineering problems in mountain streams. When constructing block ramps,one can use the dissipative behaviour of large macroroughness elements randomly placed on the river bed to enhance fish migration in an upstream direction thus, in this sense, meeting the requirements of the EU Water Framework Directive. Block ramps are often designed and constructed to replace damaged drop hydraulic structures in the channels of mountain streams. This paper investigates the resilience of a particular block ramp placed in the Krzczonówka stream(Polish Carpathians) in terms of the engineering design function and its durability against damaging. A hydrodynamic analysis of a block ramp is presented before and after a flood event that changed the configuration of the blocks. The seminatural unstructured hydraulic structure was built on the Krzczonowka stream to protect gas pipes which are located beneath it. As a result of several floods, the boulder block chute described in this paper was damaged, and some boulders were dislodged and transported downstream. Our post-flood investigations of bathymetry and velocity revealed that even damaged boulder blocks, removed from the chute and displaced downstream of the structure, still provide significant energy dissipation of the flowing water. The novel of our paper is for the first time showing very detailed analysis of unstructured block ramp hydrodynamics parameters done in the field.Also the novel finding of our investigations shows that before and after the flood event the unstructured block ramp structure, is still fish friendly in terms of hydrodynamics.     

Heat capacities of Tschermak substituted Fe-biotite

Six members of the annite–siderophyllite join were synthesized in a three step process – crystallization of biotite from gels, decomposition of the fine-grained biotite under oxidizing conditions and resynthesis of Fe-Al biotite with planned compositions from these products – producing biotite crystals with thicknesses of up to 10 μm. The biotite was characterized by microprobe, electron microscopy and X-ray diffraction. Heat capacities of these biotites were measured with a DSC (differential scanning calorimeter) over the temperature range 143 to 623 K. Using a least-squares technique, the data were fitted to a c_p-polynomial, c _p =k ₀+k ₁ T ^−0.5+ k ₂ T ⁻²+k ₃ T ⁻³. In the temperature range 143 to 250 K, heat capacities of the different annite–siderophyllite members decrease linearly with increasing Al content. At higher temperatures, however, the c_p-polynomial of biotites with intermediate composition (except Ann₇₉Sid₂₁) exhibit a steeper slope than those of other biotites. This produces positive excess heat capacities in the annite–siderophyllite join at higher temperatures. The activity-composition data of the same binary derived from phase equilibrium experiments (Benisek et al. 1996) and the data of this study suggest two compositional regions along this join, with different extent of deviation from ideality. One at X _Sid < 0.3, characterized by a small deviation, one at X _Sid > 0.3 showing a higher nonideality, resulting in a discontinuity visible at this composition. Powder IR-spectra of these solid solutions were measured with a FTIR-spectrometer and used to calculate heat capacities according to the vibrational model of Kieffer (1979). The comparison of the vibrational function with the c_p-polynomials shows that the vibrational function reproduces well the DSC-data of the siderophyllite-poor and -rich members, but deviates for intermediate compositions, where the excess heats of mixing occur. With increasing Tschermak vector, the tetrahedral rotation angle α increases from 0 to 13° for annite to siderophyllite, respectively. At the composition of the discontinuity, this rotation angle α reaches a value of ∼8^∘. The processing of ∼300 chemical data of natural biotites indicates that over 90% of them have a tetrahedral rotation angle that lies between 7 and 9°. It would appear that biotites with these structural characteristics are most stable. Received: 27 August 1998 / Accepted: 10 November 1998     

Fractionation of heavy metals in bottom sediments using Tessier procedure

The study presents the results of Cu, Pb, Zn, Mn and Fe determination in the samples of bottom sediments collected from the Oder and Warta rivers. The sequential extraction of metals in the samples of bottom sediments was performed after introducing the modification of the extraction scheme suggested by Tessier et al. (Anal Chem 51(7):844–851, 1979). The extraction times of particular stages were optimised. The fifth stage was altered by introducing the new methods of performing extraction. The samples of bottom sediments submitted the following granulometric analyses: dry, wet and wet with (HMP) dispersing reagent. Seven granulometric fractions with the following grain sizes were isolated: >2.0, 2.0–1.0, 1.0–0.5, 0.5–0.25, 0.25–0.1, 0.1–0.063 and <0.063 mm. The sequential extraction of particular granulometric fractions was performed. The concentration of metals variability was analysed depending on the method of sample preparation for the chemical analysis, granulometric fraction of sediments subjected to the analysis, extraction conditions and the site of samples collection. The lack of linearity between the metal concentration and the size of granulometric fraction was observed. The highest concentrations of metals were observed in fractions >2.0, 2.0–1.0 and 0.1–0.063 and <0.063 mm while the lowest concentrations occurred in fractions 1.0–0.5, 0.5–0.25, and 0.25–0.1 mm. The atomic absorption spectrometry with flame atomisation (F-AAS) was used for the determination of the investigated elements.     

Geology,stratigraphy and palaeoenvironmental evolution of the Stephanorhinus kirchbergensis-bearing Quaternary palaeolake(s) of Gorzów Wielkopolski (NW Poland,Central Europe)

The sedimentary succession exposed in the Gorzów Wielkopolski area includes Eemian Interglacial (MIS 5e) or Early Weichselian (MIS 5d–e) deposits. The sedimentary sequence has been the object of intense interdisciplinary study, which has resulted in the identification of at least two palaeolake horizons. Both yielded fossil remains of large mammals, alongside pollen and plant macrofossils. All these proxies have been used to reconstruct the environmental conditions prevailing at the time of deposition, as well as to define the geological context and the biochronological position of the fauna. Optically stimulated luminescence dating of the glaciofluvial layers of the GS3 succession to 123.6 ± 10.1 (below the lower palaeolake) and 72.0 ± 5.2 ka (above the upper palaeolake) indicate that the site formed during the Middle–Late Pleistocene (MIS 6 – MIS 5). Radiocarbon-dating of the lacustrine organic matter revealed a tight cluster of Middle Pleniglacial Period (MIS 3) ages in the range of ~41–32 ka cal bp (Hengelo – Denekamp Interstadials). Holocene organic layers have also been found, with ¹⁴C ages within a range of 4330–4280 cal bp (Neolithic). Pollen and plant macrofossil records, together with sedimentological and geochemical data, confirm the dating to the Eemian Interglacial.     

Reconstruction of subglacial depositional conditions based on the anisotropy of magnetic susceptibility: an example from Dębe (central Poland)

The analysis of low-field anisotropy of magnetic susceptibility (AMS) was used to reconstruct the subglacial deposition conditions during the Main Stadial of the Odranian Glaciation (MIS 6) in till deposits from a site in Dębe (central Poland). Based on the AMS parameters, six till beds were identified (intervals 1–6). The declination of the maximum magnetic susceptibility axis (k₁) indicates that the ice sheet was moving in from the northwest. The obtained results confirm the thesis about the preferred direction of ice-sheet transgression during the Odranian Glaciation (MIS 6) in this part of Poland. This interpretation is also confirmed by data obtained from measurements of the long axis of clasts, which agree with the orientation of k₁. Based on the AMS results, a significant part of the profile was deformed through simple shear and direct interaction of the ice sheet with the underlying sediment (beds 2–5). The lowest part of the till (bed 6) may have been deposited on a southeast-trending slope or post-depositional deformed by uneven loading of the ice cover. The upper part of the profile (especially in interval 1) could be deposited with an impact of pore water.     

Fossil fuel compounds from fly dust in recent organic matter of southern Poland peats

Several samples of peat from 6 bogs located in southern Poland were investigated for occurrence and distribution types of biomarkers present in their extractable organic matter fraction. It was found that there are inputs from two different sources of organic compounds differing in their characteristics and origin: (1) recent immature peat organic matter deposited in situ which is the source of all polar functionalized compounds, most of n-alkanes, and acyclic isoprenoids, and (2) mature fossil fuels, most probably bituminous coals from the Upper Silesia Coal Basin of vitrinite reflectance equivalent values of 0.9–1.1%. The latter compounds were most probably transported with fly ash to bogs from nearby settlements utilizing such fuel in domestic ovens. This group includes pentacyclic triterpenoids (hopanes and moretanes), minor amounts of n-alkanes, and numerous alkyl naphthalenes and alkyl phenanthrenes. All these compounds show distributions and values of geochemical ratios characteristic for mature organic matter confirming there ex situ origin.     

First Palaeozoic arachnid from Portugal and implications for Carboniferous palaeobiogeography

The first occurrence of arachnids (Aphantomartus pustulatus) in the Carboniferous strata of Portugal is documented and its palaeobiogeographic significance is assessed. The Aphantomartidae species are thought to be native to Central Europe where its oldest example is recorded in Middle–Upper Mississippian strata. Known occurrences are preserved along the flanks of mountains such as the Appalachian Mountains, the Cantabrian Mountains and the Valongo Anticline (Portugal, Iberian Massif) and provide clear evidence that the Aphantomartidae species probably lived in upland or mountainous environments. The Iberian Massif may have served as a ‘link’ between the migration routes of several terrestrial animals from North America and Eurasia, and this linkage constrains the palaeogeographic and palaeoenvironmental conditions in equatorial Pangaea during the Carboniferous and Early Permian. Copyright © 2012 John Wiley & Sons, Ltd.     

Geodetic monitoring of tectonic deformation in the Australian region

A number of geodetic techniques exist for measuring instantaneous crustal motions and deformations. Over distances of a few hundred kilometres, conventional terrestrial methods can achieve accuracies of about 1–2 parts in 10⁶ for horizontal positions, but most existing triangulation networks in Australia are of lower accuracies. Geodetic levelling can provide height‐difference measurements with an accuracy of a few mm for points separated by about 100 km, but actual accuracies are often much lower than this. For points separated by longer distances, from a few 100 km to several 1000 km, space techniques can provide precisions of 5–10 cm. Two experiments carried out in Australia confirm that these precisions can be reached. A laser ranging experiment between sites near Canberra and Perth produced a baseline that is precise to better than 10 cm, and a radio‐interferometry experiment between Canberra, Parkes and Sydney produced baselines with precisions of 10 cm. Further evaluation of both systems is required, but the present results indicate that crustal deformations of the order of 10 cm can be measured with repeat surveys.     

Fate of trace elements during alteration of uraninite in a hydrothermal vein-type U-deposit from Marshall Pass, Colorado, USA

Alteration of uraninite from a hydrothermal vein-type U-deposit in Marshall Pass, Colorado, has been examined by electron microprobe analysis in order to investigate the release and migration of trace elements W, As, Mo, Zr, Pb, Ba, Ce, Y, Ca, Ti, P, Th, Fe, Si, Al, during alteration, under both reducing and oxidizing conditions. The release of trace elements from uraninite is used to establish constraints on the release of fission product elements from the UO₂ in spent nuclear fuels. Uraninite occurs with two different textures: (1) colloform uraninite and (2) fine-grained uraninite. The colloform uraninite contains 1.04-1.75 wt% of WO₃, 0.16-1.70 wt% of As₂O₃, 0.06-0.88 wt% of MoO₃; whereas, the fine-grained uraninite retains 2.25-4.93 wt% of WO₃, up to 5.76 wt% of MoO₃, and 0.26-0.60 wt% of As₂O₃. The near constant concentration of incompatible W in the colloform uraninite suggests W-incorporation into the uraninite structure or homogeneous distribution of W-rich nano-domains. Incorporation of W and Mo into the uraninite and subsequent precipitation of uranyl phases bearing these elements are critically important to understanding the release and migration of Cs during the corrosion of spent nuclear fuel, as there is a strong affinity of Cs with W and Mo. Zoning in the colloform texture is attributed to variation in the amount of impurities in uraninite. For unaltered zones, the calculated amount of oxygen ranges from 2.08 to 2.32 [apfu, (atom per formula unit)] and defines the stoichiometry as UO_2+x and U₄O₉; whereas, for the altered zones of the colloform texture, the oxygen content is 2.37-2.48 [apfu], which is probably due to the inclusion of secondary uranyl phases, mainly schoepite. The supergene alteration resulted in precipitation of secondary uranyl minerals at the expense of uraninite. Four stages of colloform uraninite alteration are proposed: (i) formation of an oxidized layer at the rim, (ii) corrosion of the oxidized layer, (iii) precipitation of U⁶⁺-phases with well-defined cleavage, and (iv) fracture of the uraninite surface along the cleavage planes of the U⁶⁺-phases.