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M.Sc. / The Mesoarchean Witwatersrand and Pongola Supergroups of South Africa are the oldest, well preserved supracratonic successions worldwide. Various banded iron formation (BIF) and iron-rich mudstone units occur within the West Rand Group of the Witwatersrand Supergroup and the Mozaan Group of the Pongola Supergroup. A granular iron formation (GIF) occurs in a single unit in the Nconga Formation of the Mozaan Group. The Witwatersrand Supergroup and Mozaan Group have been lithostratigraphically correlated and are interpreted to have been part of the same sedimentary basin. The studied BIF units occur in two associations: shale-associated and diamictiteassociated BIF. The GIF seem to have been deposited in shallower environments with greater hydrodynamic activity. The iron-rich mudstone shows a similar stratigraphic setting to that of the shale-associated BIF. The lithostratigraphic setting of the Witwatersrand-Mozaan basin BIFs are similar to what is seen for Superior-type ironformations, with the mudstones and associated BIFs marking marine transgressions. Various mineralogical facies of BIF were identified, including oxide, carbonate and silicate facies BIF, as well as mixed facies between these end members. The GIF is a unique facies and shows abundant petrographic evidence for biological activity. The iron-rich mudstone has been subdivided into iron-silicate rich, magnetite-bearing, carbonate-bearing, magnetite-carbonate-bearing and garnet-bearing subtypes. BIF, GIF and iron-rich mudstone have been subjected to lower greenschist facies metamorphism with some occurences of localized contact metamorphism. The abundance of magnetite shows that oxidation played an important part in BIF deposition, whereas the occurrence of 12C-enriched iron-rich carbonates suggests post depositional reduction of the deposited oxidized iron-rich minerals by organic matter. Al-bearing minerals are rare in the BIFs xxi and abundant in the iron-rich mudstones. Apatite and rare earth element (REE)- phosphates occur throughout. The major element geochemistry shows an inverse proportionality for Fe and Si in all the studied samples. BIFs show slightly higher Fe- and lower Si- and Al-concentrations compared to iron-rich mudstones which show higher Si- and Al- and lower Feconcentrations. The studied BIFs show major element geochemical attributes intermediate to those of Superior- and Algoma-type iron-formations. Provenance studies on some of the iron-rich mudstones illustrate that they were sourced from a mixture of mafic and felsic sources. The rare earth element (REE) geochemistry suggests strong hydrothermal input into the units, and positive correlation with the Fe-concentrations suggests that the Fe was introduced by high temperature hydrothermal fluids. The majority of the REEs are hosted by apatite and the REE-phosphates monazite and xenotime. The REEs were reconcentrated into these phosphates during diagenesis. A comparison of the studied lithostratigraphically correlatable units between the Witwatersrand Supergroup and Mozaan Group makes it possible to construct a depositional model for basin-wide BIF deposition in the Witwatersrand-Mozaan basin. Shale-associated BIF was deposited during the peak of transgression when reduced Ferich hydrothermal bottom waters were introduced into shallow ocean water that was either oxygenated or filled with anoxygenic phototrophic bacteria. Diamictite-associated BIF, in contrast, was deposited during interglacial periods when the melting of glacial ice introduced sunlight, nutrients and oxygen to the reduced, hydrothermally influenced Ferich ocean water. GIF was probably deposited in shallow, above wave base waters cut off from clastic input, and then washed into deeper depositional environments. Iron-rich mudstone was deposited in a similar setting as the shale-associated BIF, but in environments that were not completely cut off from detrital influx. The study shows that it is impossible to construct a general depositional model for Precambrian BIFs, since the lithostratigraphic and depositional settings vary between different examples of BIF.

This study is an extensive lithological, petrographical, mineralogical and geochemical description of fresh Collingham Formation core samples collected from borehole SFT 2, located on the farm Slangfontein, south of Jansenville in the Eastern Cape, South Africa. The borehole, drilled to 295 m on the northerly limb of a shallow westerly plunging syncline, intersected the lower Ecca Group rocks of the Ripon, Collingham, Whitehill and Prince Albert Formations and terminated in the upper Dwyka Group. A comprehensive log and stratigraphic column were compiled for the Collingham Formation and fresh core samples were analysed using X-Ray Diffraction (“XRD”), X-Ray Fluorescence (“XRF”), mercury porosimetry, and Total Organic Carbon (“TOC”). Thin section microscopy and Scanning Electron Microscopy (“SEM”) analyses were carried out on selected samples of core from borehole SFT 2. The matrix supported, massive to laminated lithological units of the Collingham Formation are interpreted as detrital, terrigenous sediments. These sediments are composed of intercalated fine-grained, poorly sorted, non-fissile mudstone; fine- to very fine-grained, predominantly pyroclastic airfall tephra; and less common fine-grained sandstones. Sediments of the Collingham Formation are considered to be immature, composed primarily of clay and aluminosilicates. The predominance of a clay fraction and aluminosilicates in mudstone samples is indicated by elevated K2O/Al2O3 ratio values, and the relationship of Zr, Al2O3 and TiO2. The presence of glauconite within the Collingham Formation indicates deposition in a mildly alkaline, slightly reducing marine environment. Rb/K ratio values (1.9 – 2.3 x 10-3) indicate brackish to slightly marine conditions, while low Zr/Rb ratio values indicate a low hydro-energy environment, with stable bottom water conditions. Hf and Nb concentrations indicate that detrital input was greatest during the deposition of tuffaceous units; while stable mineral assemblages and a low Fe2O3/K2O ratio values indicate deposition close to the source. A variation in Si/Ca values indicate times when sediments were affected by turbidity, interspersed with times of relative quiescence. The predominance of K2O over Na2O indicates that the Collingham Formation is alkali-rich, while SiO2/Al2O3 ratio values and the relationship of Zr, Al2O3 and TiO2 indicate that sediments are immature. In the lower portion of the formation, non-sulphidic, anoxic conditions are indicated by Mn/Al, V/(V+Ni), V/Cr ratio values, the Fe-Mn- V content, and the correlation between V and TOC. The upper portion of the formation is considered dysoxic, due to the presence and distribution of pyrite framboids, which indicate a fluctuating O2 level, likely indicating deposition at the interface between anoxic and slightly more oxic conditions. V/Cr ratio values indicate that the O2 regime was lowest during the deposition of the mudstones. The Chemical Index of Alteration (“CIA”) indicates a consistent weathering regime throughout the deposition of the Collingham Formation, associated with a temperate climate on the interface between glacial and tropical conditions. Although an anoxic and low hydro-energy environment is generally favourable for hydrocarbon accumulation, the Collingham Formation contains low levels of Total Organic Carbon (well below 0.9 per cent) and low porosities (ranging from 0.35 per cent to a maximum of 2.22 per cent), both of which are characteristic of a poor source for gas accumulation. Due to the laminate nature, permeability and fracturability of the Collingham Formation, there is the potential that the formation may form a good sealing sequence to the potentially gas-rich Whitehill Formation below. The metamorphic impact related to the Cape Orogeny (± 250 Ma), and reflected in the textures of the minerals making up the sediments of the Collingham Formation, suggests the enhancement in the sealing efficiency of this formation.

Southern rock bands of the 1970s were a cultural formation that displayed racially and politically progressive views in the post-civil rights South through the cultural form of southern rock music. Southern rock bands, such as The Allman Brothers Band, and Lynyrd Skynyrd, responded to the political and social changes in the South brought forth by the civil rights movement by reconciling pride for southern heritage with progressive racial views through their music. The southern rock era was essentially between the years of 1969, when The Allman Brothers Band released their first album, until 1977, whe n a tragic airplane crash took the lives of members of Lynyrd Skynyrd, including lead singer Ronnie Van Zant. Southern rock music was both a reflection of, and a response to, the changing way of life for southerners as a result of the civil rights movement. The political and cultural shift that occurred because of the civil rights movement forced many in the South to reexamine traditions and regional identities. Although many southerners had a strong sense of regional pride, the civil rights movement exposed many of the unfavorable characteristics of the South, and forced southerners to reexamine what it meant to be a "southerner." As those in the South reexamined their southern identities, southern rock bands emerged and offered a way to embrace southern pride, while rejecting traditional racist views, through the cultural form of music. As a cultural formation, southern rock bands not only demonstrated progressive racial views, they also demonstrated progressive political views through the lyrics and subjects of their songs, as well as by actively participating in the 1976 presidential campaign of Jimmy Carter. The cultural form of southern rock music is political in that many songs address social issues like racial injustice, poverty, gun control, domestic violence, and drug and alcohol abuse. These inclinations towards liberal politics went against the political trend being set by many white southerners who increasingly supported the more conservative Republican Party in the post-civil rights South.

Nutrient dynamics in the Archean-Paleoproterozoic oceans strongly influenced primary productivity and the rise of atmospheric O2. Reconstructing the cycling of key nutrients such as dissolved inorganic phosphate (DIP) at this time is important for our understanding of the timing, rate and extent of atmospheric oxygenation at this time. Banded iron formations (BIF) can be used as proxies for global DIP content in Precambrian marine waters. Estimating Precambrian DIP requires understanding of the mechanisms by which Fe(III)(oxyhydr)oxides scavenge DIP which has come mainly from experimental studies using NaCl solutions that mimick Precambrian marine conditions with for example, elevated Si and Fe(II) concentrations. The two DIP binding modes suggested for Early Proterozoic marine waters are 1) Adsorption - surface attachment on pre-formed Fe(III) (oxyhydr)oxides, and 2) Coprecipitation - incorporation of P into actively growing Fe(III) (oxyhydr)oxides. It has been suggested that the elevated Si concentrations suggested for Precambrian seawater, strongly inhibit adsorption of DIP in Fe(III)(oxyhydr)oxides. However recent coprecipitation experiments show that DIP is strongly scavenged by Fe(III)(oxyhydr)oxides in the presence of Si, seawater cations and hydrothermal As. In this study we show that the DIP uptake onto Fe(III)(oxyhydr)oxides by adsorption is less than 5% of that by coprecipitation. The data imply that in the Early Proterozoic open oceans, the precipitation of Fe(III)(oxyhydr)oxides during mixing of deep anoxic Fe(II)-rich waters with oxygenated ocean surface waters caused DIP removal from surface waters through coprecipitation rather than adsorption. Local variations in DIP and perhaps even stratification of DIP in the oceans were likely created from the continuous removal of DIP from surface waters by Fe(III)(oxyhydr)oxides, and its partial release into the anoxic bottoms waters and in buried sediments. In addition to a DIP famine, the selectivity for DIP over As(V) may have led to As enrichment in surface waters both of which would have most likely decreased the productivity of Cyanobacteria and O2 production. / Näringscirkulationen i haven under arkeikum och paleoproterozoikum påverkade primärproduktionen och uppkomsten av atmosfärisk syrgas (O2). För att förstå när och hur fort koncentrationen av O2 i atmosfären ökade behöver vi rekonstruera hur viktiga näringsämnen, t.ex. löst oorganiskt fosfor (engelska “Dissolved Inorganic Phosphorous”, DIP) cirkulerade. Bandad järnmalm (engelska “Banded Iron Formations”, BIF) kan användas som en markör för DIP i de prekambriska haven. För att kunna använda DIP som markör måste man förstå hur prekambrisk DIP tas upp av järn(III)(oxyhydr)oxider. Hittills har detta studerats med natriumkloridlösningar som ska efterlikna förhållande i de prekambriska haven, med t.ex. förhöjda kisel- och järn(II)-koncentrationer. Ur sådana studier har två bindningsmekanismer föreslagits för paleoproterozoiskt havsvatten 1) Adsorption, d.v.s. DIP binds till ytan på redan bildade kristaller av järn(III)(oxyhydr)oxid, och 2) samutfällning, d.v.s. upptag av fosfor i kristaller av järn(III)(oxyhydr)oxid medan kristallerna bildas. Det har föreslagits att de höga kiselkoncentrationerna som tros ha funnits i de prekambriska havsvattnet hämmade adsorption av DIP på ytan av järn(III) (oxyhydr)oxidkristaller. Men de senaste samutfällningsexperimenten tyder på att järn(III) (oxyhydr)oxid effektivt tar upp DIP även i närvaro av kisel, arsenik från hydrotermala källor och de katjoner som dominerar i havsvatten. I här presenterad studie var mängden DIP som bands till järn(III)(oxyhydr)oxidkristaller genom adsorption mindre än 5 % av den DIP som togs upp av kristallerna via samutfällning. Våra data tyder på att när järn(III) (oxyhydr)oxid fälldes ut i tidiga-proterozoiska hav när järn(II)-rikt djupvatten blandades med syrerikt ytvatten, och att DIP avlägsnades från ytvattnet genom samutfällning snarare än adsorption. Lokala variationer av DIP-koncentrationer i haven, möjligen även skiktning, kan ha orsakats av kontinuerlig utfällning av järn(III)(oxyhydr)oxider ur ytvattnet följt av partiell frigörelse av DIP i syrefria djupvatten och sediment. Kristallisationsprocessen, som gynnar inbindning av DIP och misgynnar inbinding av arsenik (V) kan ha orsakat brist av DIP och anrikning av arsenik i ytvattnet, vilket troligen minskade tillväxten av cyanobakterier med lägre syrgasproduktion som följd. / CLAPO

The purpose of this research is to design a proof of concept system that is capable of locating a hidden radio transmitter and to investigate methods of multi-agent formation control with a specific interest in the effectiveness of these methods on the overall objective of locating this transmitter. A system is proposed and developed in which autonomous agents work together to locate this transmitter and their responsiveness is analyzed while using formations based both on a behavioral system and a system derived from centroidal Voronoi tessellations. Many software adaptations to the existing MASnet program are required, as well as some hardware adaptations, including development of a robust simulation platform that may be used in conjunction with the MASnet system, and exploration of a distributed formation system. While this work does not accomplish the overall goal of the MASnet platform -- to be able to locate and control a diffusion process -- it does further understanding of the way autonomous agents interact with their environment and develop tools that aid future research in the program, as well as introduce exciting new areas to which the platform can be applied.

The Middle Cambrian Langston and Ute formations were studied in the northern portion of the Bear River Range and the south-central part of the Portneuf Range in southeastern Idaho. The rocks of the Langston and Ute formations were divided into 17 different rock types. The 17 rock types were formed within four recognizable lithofacies: I) Shoal - or Coastal -Peritidal Carbonate Complex; 2) Agitated Shoal; 3) Inner Marine Shelf; and 4) Outer Marine Shelf. Clastic sediments belonging to the Spence Shale Member of the Langston Formation (outer marine shelf) were deposited over the carbonate complex . A transgressive sequence marks the base of both formations. Paleomagnetic evidence suggests that during the time of the deposition of the two formations, the study area was located near the outer reaches of an equatorial epeiric sea. Clay mineralogy of insoluble residues suggests a warm, humid, tropical climate. Eogenetic diagenetic features include compaction, cementation, aggrading, and degrading neomorphism, birdseye structures, and initiation of dolomitization . Mesogenetic diagenetic features include dolomitization and pressure solution. Telogenetic diagenetic features are confined to fracturing and subsequent calcite infilling, and the oxidation of pyrite. Massive dolomitization in the northernmost section is believed to be the result of a downward flux of fluids originating as hypersaline brines. The nonconformable lower contact, conformable upper contact, the vertical and lateral extent of dolomitization, and the general association with coastal-peritidal facies have led to this conclusion. Two other subordinate types of dolomite are believed to be the result of: 1) the release of magnesium caused by the decomposition of magnesium-rich organic matter; and 2) the formation of a secondary ferroan dolomite as Fe/Mg ratios in the precipitating fluids increased under reducing conditions.

We present an investigation of two non-equilibrium systems: spatial many-species predator-prey games and systems of interacting magnetic skyrmions. We numerically study two predator-prey systems characterized by nested pattern formations. We first consider a six species game in which spiral patterns spontaneously form within coarsening domains. Through a systematic investigation of relevant correlation functions, the interface width, and other quantities, we show that the non-trivial in-domain dynamics affect the coarsening process and the interfacial properties. The exponents which govern domain growth, aging, and interface fluctuations differ from those expected from curvature driven coarsening. The response to perturbations of the reaction rates is also studied. Furthermore, we introduce a nine species model characterized by nested spiral pattern formations. Quantitative evidence of the existence of two length and time scales associated to the spiral levels is presented in the form of correlation lengths and a temporal Fourier analysis of the species densities. A generalized interaction scheme is proposed for dynamically generated hierarchies. Magnetic skyrmions are particle-like spin configurations found in certain chiral magnets. We study the effect of the Magnus force on the relaxation dynamics through Langevin molecular dynamics simulations. The Magnus force enhances the disorder of the system at high noise strengths while we observe a dynamic regime with slow decaying correlations at low noise strengths. The different regimes are characterized by changes in the aging exponent. In general, the Magnus force accelerates the approach to the steady state. In the presence of quenched disorder, we find that the relaxation dynamics are more robust in systems with a strong Magnus force. We also examine periodically driven skyrmion systems and show that a transition from reversible to irreversible flow exists in the presence of attractive defects. The Magnus force enhances the irreversible regime in this case. The work on predator-prey systems was supported by the U.S. National Science Foundation through Grant No. DMR-1606814 whereas the work on skyrmions was supported by the US Department of Energy, Office of Basic Energy Sciences (DOE-BES), under Grant No. DE-FG02-09ER46613. / Doctor of Philosophy / We present an investigation of two non-equilibrium systems: spatial many-species predator- prey games and systems of interacting magnetic skyrmions. We numerically study two predator-prey systems characterized by nested pattern formations. We first consider a six species game in which spiral patterns spontaneously form within coarsening domains. Through a systematic investigation of relevant correlation functions, the interface width, and other quantities, we show that the non-trivial in-domain dynamics affect the coarsening process and, to a greater extent, properties at the interface between competing groups of species. The exponents which govern domain growth, aging, and interface fluctuations are shown to differ from those expected in typical games of competition. We also study the change of the system due to a perturbation of the reaction rates, which could represent an abrupt change in the environment. Furthermore, we introduce a nine species model characterized by the emergence of nested spiral pattern formations. Quantitative evidence of the existence of two distinct spiral levels is presented. We also propose a generalized interaction scheme for dynamically generated spiral hierarchies. Magnetic skyrmions are particle-like spin configurations found in certain chiral magnets. We study the effect of the Magnus force on the dynamic properties of skyrmion systems through particle-based simulations. The Magnus force enhances the disorder of the system at high noise strengths while accelerating the formation of the triangular lattice at low noise strengths. We find that, in general, the Magnus force accelerates the approach to the steady state. In the presence of randomly placed attractive pinning sites, we find that a strong Magnus force can prevent caging effects and allow skyrmions to more easily move around pinning sites. We also examine periodically driven skyrmion systems and show that a transition from reversible to irreversible flow exists in the presence of attractive defects. The Magnus force is shown to enhance the irreversible regime in this case. The work on predator-prey systems was supported by the U.S. National Science Foundation through Grant No. DMR-1606814 whereas the work on skyrmions was supported by the US Department of Energy, Office of Basic Energy Sciences (DOE-BES), under Grant No. DE-FG02-09ER46613.

This dissertation explores how language has evolved as metastatic breast cancer (MBC) has shifted from an imminent death sentence to a potentially chronic disease. War rhetoric, of which the survivor trope is a part, has been the primary mechanism by which healthcare defines the cancer experience. Using Celeste Condit's framework of rhetorical formations, I question if a new rhetoric of breast cancer is indeed emerging as new developments in medicine allow women with terminal disease to live longer. My data reveals that this new rhetorical formation, of which metavivor rhetoric is the anchor point, contains its own key metaphors and rhetorical appeals. In metavivor rhetoric, the focus becomes living with cancer, in which simply existing through a sense of homeostasis develops as the central part of the rhetoric. In this homeostasis as the key part of metavivor rhetoric, a cure is not the focus, as it is in survivor rhetoric. I explore how this emerging rhetoric supersedes the war rhetoric that is deeply entrenched in medical discourse--especially breast cancer--for decades, and how metavivor rhetoric builds upon and repudiates the war rhetoric. Through my qualitative rhetorical analysis of a popular breast cancer message board for patients with metastatic disease, I coded 589 posts to see how women use language to discuss living with MBC, and Condit's concept of rhetorical formations allows me to argue more specifically for the changes I see in patient discourse. My analysis revealed that women living with MBC argue against war/survivor rhetoric and prefer metavivor rhetoric and its ancillary terms, allowing them to transition to an acceptance of their own mortality. I conclude that a new rhetorical formation has taken shape within MBC patient discourse, with implications for women's mortality as they live with a chronic disease, and as I look to the future of this research, my goal is to promote rhetorical changes that will help to enfranchise women with MBC into the broader breast cancer discourse in the United States. / Doctor of Philosophy / Metastatic breast cancer has become a disease that some women can live with for many years, as treatments have advanced for this specific type of cancer. As this disease has become a chronic condition for many women, the language that women use to discuss living with chronic cancer has also shifted. Using the framework of Celeste Condit's rhetorical formations, which encompasses uses of metaphors, topics, and values, among other rhetorical features, I examine how language has shifted from one of war and survivor rhetoric to that of metavivor rhetoric. In metavivor rhetoric, the focus becomes living with cancer, through a sense of homeostasis and of simply existing with cancer. Within homeostasis as the key part of metavivor rhetoric, a cure is not the focus, as it is in survivor rhetoric. By examining how women talk about living with cancer on a popular online breast cancer support group, I analyze the shifts that take place in their language and argue that women have moved from the dominant war and survivor rhetorical formation to one that is grounded in metavivor rhetoric and the idea of homeostasis. Within this evolution comes a transition to their own mortality as they come to better understand what it means to live with a chronic, yet ultimately, terminal, illness and an acknowledgment of the impact that their lives' perceived time has on these language choices.