Scope and contents: An investigation into some arctic soils located on Southwest Devon Island. Some aspects of chemical weathering in the area are considered and detailed studies of patterned ground are undertaken. A terrain map was compiled to locate the major areas of soils and mineral and organic covers and to show this relationship to relief units. / No abstract provided. / Thesis / Master of Science (MSc)

Understanding the natural processes that have taphonomic effects on bone is an important part of accurately determining the postmortem interval (PMI). Ultraviolet radiation is one of these various natural processes that weather bone. The present study quantifies the degree to which differential exposure to sunlight affects bone bleaching and weathering. In this study, 140 Sus scrofa long bones were placed in two different microenvironments (grassland and woodland) within a New England setting. Upon the completion of a one-year observation period, 100% of the bones had reached bleaching level 4, and 9.85% (n = 13) of the bones had reached weathering stage 1, with the majority (n = 11) being from the woodland sample. The results indicated that the microhabitat that each sub-sample was deposited within played a statistically significant role in the degree and rate of bleaching and weathering on the bone, with chi-square tests all indicating a p value of < 0.001. In addition, results indicated that environmental variables that led to the more rapid decomposition of soft tissue, such as temperature, humidity, and the type of plant coverage, may play a greater role in the level of bleaching and weathering achieved by the bones, rather than simply the degree of exposure to UV radiation and light intensity.

Determining where, when, and how subsurface flow affects soil processes and the resulting arrangement of soil development along flow paths is challenging. While hydrologic regime and soil solution acidity are known to influence weathering rates and soil transformation processes, an integrated understanding of these factors together is still lacking. This dissertation explores the effects of subsurface flow on the mobility and distribution of dissolved organic carbon (DOC) and base cations to explain spatial patterns in chemical weathering in a forested headwater catchment. In the first chapter, relationships between hydrologic behavior, fluxes of weathered elements, and the extent of soil elemental loss across landscape positions are established. The second chapter investigates what specific groundwater behavior best explains spatial patterns in solution DOC concentrations during storm events. Lastly, in the third chapter, near surface saturation dynamics are examined to determine when and where DOC mobilization might be enhanced by subsurface flow. Results show that weathering extent was greatest in the upper reaches of the catchment, where O horizon saturation frequency and DOC concentrations are highest. Annual base cation fluxes, which were also greatest in these positions, could indicate where weathering is likely still enhanced. Additionally, while O horizon saturation occurred across the catchment, spatial differences in DOC concentrations suggest there are other sources of acidity to groundwater solutions other than just leaching from O horizons. Shallow organic soils, near bedrock outcrops at the top of the catchment is likely this additional C source, in which drainage water is transported downslope to nearby mineral soils when water tables are high and hydrologic connectivity between soils is increased. Spring and fall storm events were identified as times when groundwater most frequently reached O horizons during the snow-free year, providing insight into the timing of these processes throughout the year. This dissertation highlights how catchment structure mediates DOC flushing events, which in turn, influences the spatial architecture of soil development and chemical weathering processes across the landscape. / Doctor of Philosophy / This dissertation explores how the movement and chemistry of groundwater influences chemical weathering in forest soils. Chemical weathering is an important process in which rocks and soils are broken down into soil nutrients and water-soluble elements. The control of weathering processes by spatial and temporal differences in water behavior across landscapes is not well understood. To address these knowledge gaps, this dissertation measured groundwater fluctuations, solution chemistry, and nutrient fluxes across a mountainous forested landscape. Results from this work found that areas with more frequent flushing of organic matter-rich soil horizons increases groundwater acidity, which can enhance weathering processes. Flushing frequency of organic horizons and soil nutrient fluxes were greatest in the highest elevation portions of the landscape, where soils were most weathered (greatest loss of soil nutrients). This study revealed that flushing events occurred most frequently in spring and fall storm events during the snow-free year, shedding light on the when weathering might be most enhanced. Overall, this research demonstrates that topographic graphic position described differences in catchment groundwater behavior and solution acidity, which contributes to predictable patterns of weathering and soil development across the landscape.

<p dir="ltr">This work focuses on understanding the response of sulfides and Fe-oxides to space weathering through the analysis of returned samples and laboratory simulations </p>

By analyzing the texture, composition and chemical composition of loess soils, the reconstruction ofpast climate regimes is enabled, which can improve our understanding of current and future climatechange. Properties such as grain size and composition, mineralogy, organic matter and chemicalcomposition can provide information about which environmental factors were present during thedeposition of the sediment, which can lead to a detailed picture of the climate history of a site. Researchon loess soils in the polar regions is particularly valuable because its climate is most rapidly affected byglobal warming. The purpose of the study has therefore been to understand and convey new data to thepaleo-climate around the Arctic by examining and analyzing loess soil sequences at a depth between 0and 175 cm from Adventdalen, Svalbard. In this study, the samples are analyzed with XRF (X-rayfluorescence) and LOI (Loss of Ignition). XRF is used to find out the mineral composition of the soils,while LOI is used to find out the percentage of organic content and carbonates.Data from the oldest part of the stratigraphic section indicate a sharp increase in weathering, from acooler period about 3000 years ago to a warming until about 2000 years ago. Weathering intensitiesderived from Na/Al-based indices show relatively frequent oscillations throughout the section, but arestable from about 100-70 cm. The high and stable weathering values during this period can probably beattributed to the Medieval Warm Period, which coincides with the relative dating of the site. Datacollected from the LOI shows a clear trend throughout the section, with a decrease in organic matterfrom 3000 BC to the present.

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Arbetet har genomförts i samarbete med Malmö Gatukontor med målet att samla in information om fiberförstärkta plastkompositer (fiber-reinforced polymer; FRP). FRP-kompositer kan vara ett intressant alternativ till konventionella byggnadsmaterial på grund av sina goda materialegenskaper. FRP har inte använts i gångbroar i Sverige tidigare och materialet är därför relativt okänt för byggbranschen. Studiens syfte var att undersöka och dokumentera beständigheten för FRP-gångbroar som påverkas av den omgivande miljön. Arbetet har genomförts som en litteraturstudie. Huvuddelen av studien fokuserade på att utvärdera olika nedbrytningsprocesser för att kunna bedöma potentiella svagheter hos FRP kompositer i gångbroar. Kopplingspunkter mellan olika delar i FRP broar har också studerats och dess inverkan på den totala beständigheten av konstruktionen har evaluerats. Studien ger en överblick av hur beständighetsparametrar för FRP-kompositer påverkas av olika typer av nedbrytning. Från denna överblick värderades nedbrytning genom fuktabsorption, höga och/eller cykliska temperaturer och UV-strålning som de faktorer som mest påverkar materialegenskaperna för FRP-kompositer. Studien konstaterar även att effekten av samverkan mellan olika nedbrytningsprocesser måste beaktas då materialet utsätts för flera olika angrepp i naturliga miljöer. Denna synergi gör att det är svårt att värdera effekten av varje enskilt angrepp. På grund av brist på information kunde inte kopplingspunkterna mellan komponenter i överbyggnadskonstruktionen i gångbroar fullständigt utvärderas, med avseende på dess påverkan på den totala beständigheten. Studien kunde dock konstatera att kopplingspunkter bör undvikas om det är möjligt, då vibrationer, utmattning och termisk expansion kan orsaka högre spänningsnivåer i kopplingspunkterna. Resultaten från studien syftar till att ge vägledande information vid projektering av gångbroar med FRP-kompositer. / This bachelor thesis was written in cooperation with Malmö Streets and Parks Department to collect information on fiber-reinforced polymer (FRP) composites. In today’s building industry, FRP composites provide an interesting alternative to conventional building materials because of their superior material properties. FRPs are suggested to be a sustainable solution meeting the future requirements in infrastructure and especially bridge design. The use of FRP composites in pedestrian bridge applications have not previously been utilized in Sweden and thus the material is relatively unknown to the building industry. The aim of this study was primarily to examine the performance in terms of durability of FRP pedestrian bridges subjected to the effects of the surrounding environment by conducting a literature review. The main part of this study was to evaluate different types of degradation to assess the potential weaknesses of FRP composites during in-service use in pedestrian bridges. The connections between the different members and components in FRP bridges were also studied and their impact on the overall durability of the construction was evaluated. The results from this study provided an overview of the durability characteristics of FRP composites subjected to different types of degradation. From this overview it was concluded that degradation by moisture absorption, high and/or cyclic temperature, and UV-radiation had the most significant impact on the material properties in FRP composites. This study also concludes that the effects of synergism between the different types of degradation need to be considered since FRP composites are subjected to many types of degradations in natural environments. Because of the effects of synergism, the individual effects of the different types of degradations can be difficult to evaluate. Due to lack of information, the impact on overall durability in pedestrian bridges from the connections between components in the superstructure could not be fully evaluated. However, it was found that connections should be avoided if possible due to vibrations, fatigue, and thermal expansions that may cause higher stress levels in the connection points. The results of this study aims to provide guidance when designing FRP composite pedestrian bridges.