Browsing by Subject "weathering"

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Badania form związania żelaza i wybranych pierwiastków śladowych w glebach polarnych metodą wielostopniowej ekstrakcji sekwencyjnej
(Data obrony: 2014-05-28) Jakubski, Grzegorz
Wydział Geologii, Geofizyki i Ochrony Środowiska
The aim of this work was to evaluate the speciation of iron, manganese and selected trace elements (Zn, Pb, and Cu) in initial polar soils located on the forefield of Werenskioldbreen glacier in West Spitsbergen. For this purpose, a multi-stage sequential extraction method has been applied for three soil samples, collected in different distances from the glacier terminus. Mineral composition and particle size distribution have been determined as well. It has been shown that in the finest grain fraction the amount of primary minerals decrease and secondary phyllosilicates and iron oxides are getting more important. Additionally, the primary phases in older soil are usually more altered than those in younger soils. As a consequence, distant (older) soils contain distinctly more iron in finer fractions and less in coarser fractions than the soil located near the glacier front. In the latter, iron is bound mainly to primary silicates and this speciation appear to be less important in the older soils, where, in turn, Fe oxides content increase. Similar variability has been found in the trace elements distribution.
Access status: Open Access ,
The geochemical composition of sediment as a proxy of provenance and weathering intensity: a case study of Southwest Nigeria’s Coastal Creeks
(Wydawnictwa AGH, 2017) Phillips, Olusegun Adebayo; Falana, Adenike Omotayo; Adebayo, Adegboyega Joel
The study of the geochemical composition of sediments was undertaken to evaluate the degree of weathering and appraise the relative proportion of mafic and felsic rock materials being transported from source to sink. Thirty-three surface sediment samples collected from the creeks were used for particle size and chemical analyses. An inductively coupled plasma-Mass Spectrometer was used to determine the elemental composition of the sediments. The clay dominated Yewa and western Badagry creeks gave evidence of higher average concentrations of $Ni$, $Sr$, $Y$, $Nb$, $Sc$, $Co$, $V$, and $Th$ than the eastern end of segment of Badagry Creek. The data generated from elemental ratios such as $Al_{2}O_{3}/TiO_{2}$, $TiO_{2}/Zr$ and binary plots of $Th/Sc-Cr/Sc$, $Th-Sc$, $Y/Ni-Cr/V$, $TiO_{2}-Zr$ and ICV-CIA (index of compositional variability against chemical index of alteration) showed that source sediments are composed of upper and lower crustal compositions. Also, the creeks were marked by their variation in terms of the proportion of felsic and mafic components. For instance, Yewa and western Badagry creeks are more enriched in mafic constituents, whereas the enrichment of felsic materials is significant at the eastern end of Badagry Creek. Inferring from the chemical index of alteration and plagioclase index of alteration (PIA), the Yewa and western Badagry creeks have been moderately to intensely weathered and incipient weathering was identified in the eastern end of Badagry Creek.
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Wpływ na środowisko procesów wietrzenia wybranych minerałów $Fe$ i $As$ w strefie hipergenicznej w Rędzinach
(Data obrony: 2012-09-12) Kosakowski, Łukasz
Wydział Geologii, Geofizyki i Ochrony Środowiska
The active quarry of dolomitic marble is located at Rędziny, in the lower Silesia, near Kamienna Góra. A disseminated, hydrothermal polymetallic association, and in consequence of weathering the development of secondary minerals, occur in the Rędziny dolostones. The objects of this study were to evaluate the weathering process of arsenic and iron minerals, and its environmental impact. Standard mineralogical investigations (reflected light, XRD, SEMEDS and WDS analyses) were carried out for these purposes. Microscopic examination (reflected light) enabled to observe the weathering process of primary minerals. Some secondary phases were identified by XRD, and point chemical analyses (SEM, WDS). Basing on the determined concentration of arsenic in the water and field observation, it was concluded, that weathering process of arsenic and iron minerals in the quarry doesn't affect the environment in any significant way.
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Zmiany wietrzeniowe wybranych kamieni budowlanych w środowisku miejskim
(Data obrony: 2013-09-23) Ziemianek, Andrzej
Wydział Geologii, Geofizyki i Ochrony Środowiska
The weathering process of building materials is a natural phenomenon but in areas of high air pollution often characteristic of large cities like Krakow is a significant intensification. In that research the inner and outer layer of architectural objects located in the Kazimierz district, made of limestone, dolomite and sandstone. The following methods were used: optical microscopy, scanning electron microscopy SEM, X-ray diffraction XRD, Raman spectroscopy and chemical analysis. Studied rocks according to their petrography and exposure to weather conditions show different degree of deterioration. Sandstones are intense granular disintegration and limestone covered with black crusts. In the outer layers of stones the presence of phases of anthropogenic origin like: gypsum, halite, iron oxides spheres, Si-Al glass spheres and organic compounds were found. The higher concentration of heavy metals: Zn, Cu and Co in the surface layer were discovered also. These changes confirm the significant impact of air pollution on the rate of weathering in urban areas.
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Związki żelaza jako pigment w wybranych piaskowcach karpackich
(Data obrony: 2010-07-20) Drzymalski, Łukasz
Wydział Geologii, Geofizyki i Ochrony Środowiska
A phenomenon commonly observed in sandstones containing Fe-minerals is formation of layered zones of clearly different colouration, connected with various concentrations of iron compounds. Similar processes have also been described in historic buildings built of sandstones with iron cement or Fe-rich compounds. Understanding the processes of weathering sandstones rich in Fe-minerals, conditions of the mobilization and precipitation of secondary compounds and their types is important for any action aimed at conservation of the building stones. The sandstone rocks in the Polish Flysch Carpathians are particularly convenient for studying the weathering processes, in the natural outcrops having been long time exposed to the influence of the atmospheric factors. The aim of this study was to investigate the occurrence, concentration and types of the Fe-compounds in the sandstones sampled in the Polish Flysch Carpathians, as well as their impact on the colour and structure of these rocks. Diversified colouration observed in distinct layers is connected with various concentrations of the Fe-compounds. Most often they occur in form of: crystalline oxides or hydroxides, such as goethite and haematite, aluminium silicates, and amorphous phases of the ferrihydrite type. A very significant impact on the sandstone layer colouration is due to have their occurrence in form of the submicroscopic aggregates. The weathering processes also resulted in formation of secondary minerals, such as jarosite, gypsum, and halite, on the surface of the sandstone rocks.