In the last few centuries, many streams in the eastern United States have been severely disturbed by land use change and are now disconnected from their original floodplain due to the aggradation of legacy sediment. Currently, stream-floodplain reconnection is advocated as a stream restoration practice to take advantage of ecosystem services. The objective of this study is to compare two current stream restoration approaches for their nutrient flushing ability: 1) a conventional approach leaves legacy sediment on the floodplain; and 2) an ecological approach that involves removing the accumulated legacy sediment in order to restore the original floodplain surface wetland, revealing a buried A soil horizon. Soil cores were taken from the surficial legacy sediment layer and the buried A soil horizon in the floodplain of a 550-meter reach of Stroubles Creek in the Valley and Ridge province near Blacksburg, VA, to evaluate potential for flushable DOC, TDN, NO3-, NH4+, and SRP content. In addition, an inundation model was developed to evaluate the extent of flooding under the two restoration scenarios. The inundation model results and nutrient flushability levels were then used to simulate the release of nutrients as a function of stream restoration approach. Results indicate that the buried A horizon contained less flushable nutrients, but the ecological restoration would have a higher frequency of inundation that allows for more flushable nutrient release at the annual scale. Understanding the nutrient release potential from the floodplain will provide the ability to estimate net nutrient retention in different stream-floodplain reconnection strategies. / Master of Science

This research project provides a geomorphological and geological analysis of ephemeral and relict river valley systems in the north part of the Iraqi Western Desert. The area surveyed covers approximately 30 000 km2 and is one of the remotest and least studied parts of the Arabian Peninsula. Part of the reason for the lack of research in this area in recent years has been the ongoing security problems and all fieldwork undertaken for this thesis was carried out with the support of armed guards and police. In addition much of the work on the geology and geomorphology of the region is in confidential files commissioned by oil companies, and in MSc and PhD theses held in Iraqi Universities. A significant part of this work and indeed many scientific papers, are only available in Arabic. Therefore a major element of the work for this thesis has been to translate this material and make the results available in English for the first time. The study demonstrates that the present surface of the Iraqi Western Desert overall forms an incised plateau developed during two phases of continental erosion and deposition during the Tertiary and Quaternary periods. The first phase started after Oligocene uplift formed an older plateau within the Oligocene Tayarat formation. This plateau is characterized by denudation processes associated with a semiarid climate, including the formation of subsurface hollows and caves. The second phase, which began after the last Alpine Orogenic movement, and includes the Pliocene and Quaternary periods, formed a younger plateau developed on the Zahra formation. This younger plateau is characterized by processes indicative of climatic fluctuations from wet to arid and semiarid, which induced denudation in places and deposition in others. However, in terms of the geomorphological landforms present in the Western Desert they can be broadly divided into: i) Structural and erosion-denudation forms ii) Accumulation forms Lithology landform in these two categories has resulted in the production of a new geomorphological map of the Iraqi Western Desert. A key component of this map uses the drainage networks. Four distinct drainage systems were identified: 1. The valleys which descend from west to east. These valley systems are located to the south and south east town of Rutba 2. The valleys which descend from south to north. These lie to the west and southwest of Rutba and are controlled by the north to south strike of exposed Palaeogene strata. 3. The valleys which descend from east south to north west, located north of the Garaa area like Ratga and Akash. 4. The valleys which descend from east to west. These valley systems are located to the south and south west town of Rutba, like Swab and Wallaj valleys. Investigation of these four networks established that they were relict systems that still carried ephemerally active misfit rivers and stream. The overall control on their form was the alternating sequences of variable strength rocks that were exposed and eroded as part of the uplift of an anticlinorium (Houran) and anticline (Garaa), associated with the Alpine Orogeny .However, the unclearing Structures were much older and can be traced back to Permian tectonic processes. The drainage of the Western Desert, therefore, is antecedent and controlled by Tertiary and Quaternary tectonics. The rivers appear to have active throughout the Pleistocene incising into the Western Desert plateaux. Highest incision rates probably occurred during more pluvial periods in the Pleistocene which may have been coincident with glacial marine in the Northern Hemisphere. The contemporary rivers are misfit within larger valleys although still subject to flash floods under the right metrological condition.

The South Westland Continental Margin (SWCM) is incised by two major active canyon channels, the Hokitika and Cook canyons, which export large volumes of terrigenous sediment from the active New Zealand landmass to the deep ocean basins. This thesis examines modern sediment textures and compositions of shelf and canyon heads, to interpret depositional and transport processes in shelf-canyon interactions and the dispersal and provenance of SWCM surface sediments. This is the first detailed study of modern sediments south of the Whataroa River which focuses on both shelf and canyon head sediments. Submarine canyons that incise active continental shelves are major conduits for sediment transfer. The frequency and magnitude of this transfer has important implications for ocean nutrient cycling (i.e. organic carbon), the stratigraphy and morphology of continental shelves, and the development of economic mineral deposits. Grain size analysis, petrology, geochemistry, detrital magnetite analysis (microprobe), swath bathymetry, and wave hindcast data are used to interpret the spatial distribution, dispersal, and provenance of surface grab samples, canyon cores, and beach and river samples on the SWCM. Four main surficial facies are defined from textural and compositional results, primarily reflecting the supply and storm dominated nature of the SWCM. Facies 1 is comprised of inner shelf very fine to medium sand sized quartz, metamorphic lithics, and feldspar. This facies occurs above the mean Hsig wave base (48 m) where silts, clays, and sand sized micas are bypassed further offshore. Facies 2 is a transitional sand to mud facies between 40 -70 m depth where increasing clay, silt, and mica reflect a decrease in the frequency and magnitude of wave orbital remobilisation. Facies 3 is a mud dominated (80-90%), clay rich (7-9%) facies with the highest mica and Al₂O₃ content of all the SWCM facies. The shelves south of the Hokitika canyon are blanketed beyond the inner shelf in facies 3 towards the shelf break. Facies 4 is restricted to the canyon head north rims and is characterised by mixed relict and modern terrigenous sediments and glaucony. Net transport on the SWCM shelf is to the north, particularly during south-westerly storms where wind drift and storm swells may stir and transport the deeper Facies 2 and 3 sediments. The SWCM has an energetic wave climate and numerous high yield mountainous rivers. As a result the shelf has an extensive coverage of silts and clays with sediment transport most likely dominated by nepheloid layers and fluid mud flows during wet storms. North of the Hokitika canyon, shelf width increases as fluvial supply falls, resulting in a more storm dominated shelf as the prevailing hydraulic conditions prevent modern silts and clays from blanketing the outer shelf. Narrower shelf widths and higher fluvial supply between the Hokitika canyon and the Haast region results in more fluvial dominated shelves. Contrasting canyon rim textures and compositions reflect the major influence the Hokitika and Cook canyon heads impose on the SWCM by intercepting modern net northward shelf transport paths. This interception creates a leeward sediment deficit on the canyon north rims where low sedimentation rates prevail and relict sediments are partially exposed. The south and east rims of both canyons are characterised by modern fine grained terrigenous textures and compositions similar to the SWCM middle to outer shelf facies 3. The build-up and storage of these unconsolidated sediments at the south and east rims provides favourable environments for sediment gravity flows that feed into the canyon systems. Wave orbitals can resuspend fine sands up to 50 m below the canyon rims during large storms. This resuspension will be a main driver of canyon head sedimentation in the form of fluid mud flows. Gully networks along the south and east rims of the Hokitika and Cook canyons indicate active submarine erosion, unconfined fluid flow, and sediment gravity flows operate here. ii In contrast, the north canyon rims are characterised by gravels and coarse sands out of equilibrium with the prevailing modern hydraulic regime. Relict gravels are particularly prevalent on the Hokitika canyon north rim between 90 – 150 m depth. A lack of active gully networks and the presence of relict terraces and cuspate channels provide further evidence for a relict origin of HCH north rim sediments and little influx of modern fine sediments. North rim sediments on the Hokitika canyon between 90 – 125 m have features characteristic of relict beach and littoral environments. These features include pebble and coarse sand sized siliciclastics, high heavy mineral percentages (i.e. garnet), high Zr and Y levels, elevated SiO₂/Al₂O₃ ratios, and relict shell fragments. Mature glaucony is common on the north rims of both canyons, especially between 180 -200 m depth providing further evidence for extended periods of little to no modern sediment deposition in the canyon lee. Glaucony grains have experienced limited transport and are probably parautochthonous. The bulk composition of SWCM shelf, canyon, river, and beach sediments is controlled mainly by the hydrodynamic sorting of Alpine Schist derived material. Regional changes in catchment geology are identified in modern SWCM shelf sediments. Ultramafic signals (i.e. enriched trace element patterns and Cr/V and Ni/Y ratios) from the Pounamu Ultramafics and Dun Mountain Ultramafics were identified on the North and Cascade shelves respectively. The contribution of other lithologies to the bulk composition of SWCM sediments is localised due to rapid dilution with Alpine Schist detritus. The low carbonate and skeletal content on the SWCM is due to the energetic wave climate and high fluvial supply on the shelves. A variety of Cr-rich spinels and magnetites are supplied to the SWCM shelves and vary with regional changes in catchment geology. The Cascade shelf is rich in chromites (containing up to 215,000 ppm Cr) and Cr – rich magnetites sourced from the Dun Mountain Ultramafics via the Cascade River. Shelf, beach, and river samples between the Haast River and Waitaha River are dominated by low-Cr magnetite grains which represent the ‘background’ magnetite composition sourced from rivers draining the Alpine Schist dominated catchments. The dispersal of Cr-rich spinels is limited due to the dilution with low Cr-magnetites from rivers and littoral sediments. Glacio-eustatic lowstands such as the Last Glacial Cold Period (LGCP), represented periods of robust connection of local rivers with the Hokitika and Cook canyon heads, increased interception of littoral transport paths, and compartmentalisation of inter-canyon shelves. Hokitika canyon cores reflect these changes with textural and compositional ‘spikes’ indicating higher terrigenous input during the LGCP. The geochemistry of the terrigenous fraction in the Hokitika canyon provides evidence for enrichment in ferromagnesian and Cr-rich minerals during the LGCP. This is due to the increased connectivity of the Cr-spinel bearing Hokitika River to the canyon head. The Cr/V ratio in particular demonstrates its effectiveness as a proxy for interglacial – glacial change in submarine canyon stratigraphy. Increases and decreases in the connectivity of Cr-bearing fluvial systems during lowstands and highstands respectively can be observed with this ratio.

This study aimed to contribute to baseline knowledge of permafrost geochemistry within the uppermost 3-4 m of permafrost at 8 sites on the Peel Plateau and east of the Mackenzie Delta, NWT (67-68oN). The following variables were measured: gravimetric water content (GWC), pore water conductivity (PWC), leachate conductivity (LC), dissolved ions by ICP-AES (i.e. Ca, SO4, Mg, Fe, K, Na, Mn, Cl), organic carbon content (calculated by linear regression from organic matter content), as well as inorganic carbon content (obtained from loss on ignition analysis). PWC was positively correlated to GWC and values were generally at least 5 times less than LC values, likely underestimating total dissolved solutes using the former method. LC increased with depth to reach maximum values below the paleo thaw unconformity (>10 mS/cm). Carbon content typically remained low throughout the cores with the exception of samples associated to the shallow-rooted vegetation cover at the ground surface. Results showed that the active layer, relict active layer and the permafrost below the thaw unconformity can be divided into three statistically significant layers. PCA results indicated some spatial patterns with increasing LC values at greater depth, suggesting that layer geochemical profiles reflect varying degrees of soil chemical weathering processes since the early Holocene.

The presented diploma thesis deals with the effects of the Czech-German relict border on the religiosity and the sacral landscape of the city region called Manetin, which consists of the permanent Czech territory and the Nectiny village of German historical origin. The theoretical introduction of this work therefore includes a part dedicated to the topic of borders, introducing different types of borders, focusing particularly on the terms relict and ethnic borders used in the further study. The second part of the theoretical introduction contains the characteristics of the religiosity and the sacral landscape, its evolution on the national level after the Second World War, highlighting the consequent processes related to the exile of the German population after 1945. The research section of the thesis consists of the micro-regional analysis of the reference region. The analysis is based on the field study and semi-structured interviews, which were complemented by the demographic statistics. The main aim of the investigation presented in the thesis is to analyze the differences in the religiosity and the sacral landscape in the regions under study through the chosen methodological approaches and consequently to evaluate the continuity of the relict border existence. Key words: relict border,...

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Intensive cytotype screening in the primary contact zone of relict serpentine Knautia arvensis agg. revealed a striking predominance of the derivative tetraploid (81 % of subpopulations) over the diploid maternal race. Eleven mixed-ploidy subpopulations with the close spatial proximity of both cytotypes were identified. Flow cytometric analyses of almost 5 000 individuals led to discovery of two extremely rare minority cytotypes (3x, 6x). Vegetation analyses were made at two different spatial scales and in both cases confirmed the absence of distinctions in habitat preferences of cytotypes. Slight microhabitat segregation of cytotypes was however apparent at the finest spatial scales. Cytotype distribution within mixed-ploidy sites was not random. Striking patterns of cytotype clumping into cytotype uniform patches and negative spatial correlations between diploid and tetraploid individuals were apparent at all sites. Distribution of life cycle stages of diploids and tetraploids within the mixed-ploidy subpopulations were significantly different. The clonality was the most common mode of reproduction in the subpopulations of both cytotypes. Seedlings accounted for only 7 % of new plants. Significant distinctions in the plant vigour between the cytotypes were showed during the in situ comparison in...

<p>Relict non-glacial surfaces occur in many formerly glaciated landscapes, where they represent areas that have escaped significant glacial modification. Frequently distinguished by blockfield mantles, relict non-glacial surfaces are important archives of long-term weathering and landscape evolution processes. The aim of this thesis is to examine the distribution, weathering, ages, and formation of relict non-glacial surfaces in the northern Swedish mountains.</p><p>Mapping of surfaces from aerial photographs and analysis in a GIS revealed five types of relict non-glacial surfaces that reflect differences in surface process types or rates according to elevation, gradient, and bedrock lithology. Clast characteristics and fine matrix granulometry, chemistry, and mineralogy reveal minimal chemical weathering of the blockfields.</p><p>Terrestrial cosmogenic nuclides were measured in quartz samples from two blockfield-mantled summits and a numerical ice sheet model was applied to account for periods of surface burial beneath ice sheets and nuclide production rate changes attributable to glacial isostasy. Total surface histories for each summit are almost certainly, but not unequivocally, confined to the Quaternary. Maximum modelled erosion rates are as low as 4.0 mm/kyr, which is likely to be near the low extreme for relict non-glacial surfaces in this landscape.</p><p>The blockfields of the northern Swedish mountains are Quaternary features formed through subsurface physical weathering processes. While there is no need to appeal to Neogene chemical weathering to explain blockfield origins, these surfaces have remained continuously regolith-mantled and non-glacial since their inception. Polygenetic surface histories are therefore indicated, where the large-scale surface morphologies are potentially older than their regolith mantles.</p>

Relict non-glacial surfaces occur in many formerly glaciated landscapes, where they represent areas that have escaped significant glacial modification. Frequently distinguished by blockfield mantles, relict non-glacial surfaces are important archives of long-term weathering and landscape evolution processes. The aim of this thesis is to examine the distribution, weathering, ages, and formation of relict non-glacial surfaces in the northern Swedish mountains. Mapping of surfaces from aerial photographs and analysis in a GIS revealed five types of relict non-glacial surfaces that reflect differences in surface process types or rates according to elevation, gradient, and bedrock lithology. Clast characteristics and fine matrix granulometry, chemistry, and mineralogy reveal minimal chemical weathering of the blockfields. Terrestrial cosmogenic nuclides were measured in quartz samples from two blockfield-mantled summits and a numerical ice sheet model was applied to account for periods of surface burial beneath ice sheets and nuclide production rate changes attributable to glacial isostasy. Total surface histories for each summit are almost certainly, but not unequivocally, confined to the Quaternary. Maximum modelled erosion rates are as low as 4.0 mm/kyr, which is likely to be near the low extreme for relict non-glacial surfaces in this landscape. The blockfields of the northern Swedish mountains are Quaternary features formed through subsurface physical weathering processes. While there is no need to appeal to Neogene chemical weathering to explain blockfield origins, these surfaces have remained continuously regolith-mantled and non-glacial since their inception. Polygenetic surface histories are therefore indicated, where the large-scale surface morphologies are potentially older than their regolith mantles.

The presented diploma thesis deals with the effects of the Czech-German relict border on the religiosity and the sacral landscape of the city region called Manetin, which consists of the permanent Czech territory and the Nectiny village of German historical origin. The theoretical introduction of this work therefore includes a part dedicated to the topic of borders, introducing different types of borders, focusing particularly on the terms relict and ethnic borders used in the further study. The second part of the theoretical introduction contains the characteristics of the religiosity and the sacral landscape, its evolution on the national level after the Second World War, highlighting the consequent processes related to the exile of the German population after 1945. The research section of the thesis consists of the micro-regional analysis of the reference region. The analysis is based on the field study which consists of semi-structured interviews, which were complemented by the descriptive statistical analysis and method of observing the condition and location of sacral objects. The main aim of the investigation presented in the thesis is to analyze the differences in the religiosity and the sacral landscape in the regions under study through the chosen methodological approaches and...