• A study of place names in Lawrence County, Indiana

      Gratzer, Florence Elise (2013-04-09)
      Not Available.
    • AGE DEPENDENCE OF SPIRAL GRAIN IN WHITE OAKS (QUERCUS ALBA) IN SOUTHCENTRAL ILLINOIS

      Rauchfuss, Julia (Cunningham Memorial library, Terre Haute, Indiana State University, 2004-12)
      Spiral grain, the alignment of wood fibers (trachejds) to the longitudinal axis of h·ees, is thought to be an indicator of old age and is a phenomenon that has been only stndied with destrnctive sampling methods (cutting down trees). In this study, the usefulness of non-fatal sampling methods and existing methods to quantify spiral grain patterns in Jiving and dead deciduous trees are examined, particularly in white oaks (Qi1ercus alba). 111e overall goal is to detem1ine if spiral grain growth is a reasonable indicator of h·ee age. Methods that were tested included the use of a 12 mm increment borer (non-fatal sampling method) and Brazier's method ( 1965) of analyzing grain angles along just one diagonal to get a representative grain angle for the whole circumference at a certain height on a tree. The 12 mm increment borer did not produce consistent results in this study; therefore, . destructive sampling is necessary to study spiral grain in white oaks. Brazier's method (1965) should not be used in white oaks and should not be applied universally to all tree species. Samples from living and dead trees vary in severity and direction of spiral grain. The climatic factors that are roost limiting to tree growth do not influence spiral grain growth in white oaks in this stand. Severe spiral grain does in general seem to be an indicator of age in white oaks, although most trees have severe left spiral grain and not right spiral grain. However, a tree without severe spiral grain is not necessarily young. To judge the severity of spiral grain, grain angles have to be examined in the outermost layer of the wood and not in the bark.
    • Alternative Ways to Enumerate Data on Race in Puerto Rico: Are Racial Segregation and Spatial Clustering more Evident when Using a Culturally Grounded Methodology?

      Allen, Reuben (Indiana State University, 2014-08)
      Nationalist discourse concerning race in Puerto Rico generally states that residents are of the same racially mixed heritage—a combination of Spanish, West African, and indigenous ancestry of various degrees. However, literature and casual observations suggest that the population is characterized by greater variation in physical appearances than what is posited by “admixture” discourse. Moreover, and further complicating the understanding of race, 2010 U.S. Census data show that over 75 percent of Puerto Ricans self-identified as “White, alone”, and that only 3.3 percent of respondents indicated “Two or More Races.” Researchers, employers, and governmental agencies attempting to address or further analyze issues of inequality, discrimination, and residential segregation have had to rely on existing U.S. Census data to identify possible links between race and socioeconomic attainment. Thus, the need for an alternative data collection process that can be used for various forms of socioeconomic and spatial analysis has become evident. In this study, I administered alternative datasets that emphasized a locally suited, culturally grounded, and standardizable conceptual foundation for the purpose of establishing more representative racial statistics for the Puerto Rican population. The socioeconomic and spatial implications of resulting data were analyzed to determine if members of certain racial classifications are more privileged than others, and to determine if racial identity is characterized by spatial autocorrelation. Results showed that “Whites”, defined by different enumerators through various instruments, have attained slightly higher levels of socioeconomic attainment than nonwhites. However, there were no indications of spatial clustering or segregation based on race. Lastly, I interviewed a subsample of participants to garner feedback concerning their assessments of the survey instruments, their general understanding of race and historical admixture, their perceptions of racial inequality, their opinions of affirmative action, and finally, their observations of racialized spaces.
    • Analyses of seven high school geography textbooks

      Walters, Lee (2012-08-14)
      Not Available.
    • Analysis of Urban Heat Islands by Using Multi-Sensor and Multi-Temporal Remote Sensing Images

      Umamaheshwaran, Rajasekar (2011-09-20)
      This doctoral dissertation research has developed models to facilitate in characterization,analysis and monitoring of urban heat islands (UHI). Over the past few years there has been evidence of mass migration of the population towards urban areas which has led to the increase in the number of mega cities (cities with more than 10 million in population) around the world. According to the UN in 2007 around 60% (from 40% in 2000) of world populations was living in urban areas. This increase in population density in and around cities has lead to several problems related to environment such as air quality, water quality, development of Urban Heat Islands (UHI), etc. The purpose of this doctoral dissertation research was to develop a synergetic merger of remote sensing with advancements in data mining techniques to address modeling and monitoring of UHI in space and in time. The effect of urban heat islands in space and over time was analyzed within this research using exploratory and quantitative models. Visualization techniques including animation were experimented with developing a mechanism to view and understand the UHI over a city. Association rule mining models were implemented to analyze the relationship between remote sensing images and geographic information system (GIS) data. This model was implemented using three different remote sensing images i.e., Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER), Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS). The effect of the spatial resolution on the model and the phenomenon were analyzed in detail to determine variables which strongly associate with land use land cover (LULC) in space and in time.A non-parametric process convolution model was developed and was used to characterize UHI from MODIS time series images. The resulting characterized images were used to study the relationship between LULC and UHI. The behavior of UHI including its movement and magnitude was analyzed in space and time.The intellectual merits of these methods are two-fold; first, they will be a forerunner in the development and implementation of association rule mining algorithm within remote sensing image analysis framework. Second, since most of the existing UHI models are parametric in nature; the non-parametric approach is expected to overcome the existing problems within characterization and analysis. Parametric models pose problems (in terms of efficiency, since the implementation of such models are time consuming and need human intervention) while analyzing UHI effect from multiple imageries. These proposed models are expected to aid in effective spatial characterization and facilitate in temporal analysis and monitoring of UHI phenomenon.
    • Applying Geophysics and Geochemistry to Understand Middle Woodland Site Spatial Organization At the Northwood Site, Vigo County, Indiana

      Grossman, Tiffany (2012-10-22)
      The Northwood site (12Vi194) in northern Vigo County is attributed to the Late Middle Woodland culture known as Allison-LaMotte. Previous studies at other Allison-LaMotte sites are inconclusive regarding the village structure of this culture. While some studies identify a habitation zone surrounding a circular plaza, other Allison-LaMotte sites lack an observable spatial layout to the site. Magnetometry studies completed at the Northwood site in 2005 reveal a possible semi-circular community pattern with a central plaza. This study employed the 2005 magnetometer survey data, magnetic susceptibility, ground penetrating radar (GPR), and geochemical analyses to confirm the hypothesized site organization. Magnetic data from the magnetometer survey and magnetic susceptibility of artifact classes were compared to identify sources of magnetic anomalies. The map produced by magnetometry was compared with the GPR map to identify overlaps in possible pit features and the plaza zone. Excavating in locations identified as magnetic anomalies allowed for ground truthing survey results and collecting magnetic susceptibility measurements and soil samples for geochemical analysis. Geochemical analyses included detailed phosphorus geochemistry, total organic matter content, and organic carbon enhancement of soils collected from the site. Finally, determination of the source and strength of feature magnetic signals were analyzed using magnetic susceptibility and magnetometer data. These investigations provide better estimates of site spatial structure at the Northwood Site.
    • Assessing Environmental Conditions at the Friar Tuck Mining Complex, Dugger, Indiana

      McBride, Windy Jo (2011-09-20)
      Many abandoned mine lands (AML) continue to present significant environmental concerns. The abandoned Friar Tuck Mining Complex in Greene and Sullivan counties, Indiana, continues to impair local water quality despite closing in 1952 for operations and multiple remediation attempts. Most areas within the Friar Tuck Mining Complex have been successfully remediated; however, the area of research interest requires additional treatment and continues to be impacted by runoff from gob piles. Subsequently, areas characterized by a loss of vegetation where mine seeps occur behave unpredictably and are characterized by the exposure of bare soil. These mine seep areas are of particular concern because contaminated soil may leave the site during summer months as aerosols due to soil desiccation. The primary goal of this project was to evaluate spatial variability in the distribution of metals in surface soils. In May 2010, 258 soil samples were collected at the Friar Tuck Mining Complex to evaluate metal accumulation and bioavailability using several different geochemical techniques, including bulk geochemistry following reaction with water and acid and a sequential extraction technique. Results indicate that surface soils at the Friar Tuck Mining Complex continue to be degraded, pH is moderately to highly acid (pH=4-1) in areas of mine seeps, surface flow, and where the slurry pond narrows and begins to discharge into Mud creek. Surface soils also have elevated concentrations of bioavailable metals due to the persistent influence of AMD, such as Zn, Cu, Cr and Pb, especially in areas of mine seeps, surface flow, and water ponding.
    • Assessment and Impact of Gentrified Public Housing Neighborhoods in The United States: A Case Study of Chicago

      Sink, Todd W. (2011-09-20)
      Social-mix housing policies play a unique role in shaping the geography of gentrification in cities throughout the U.S. and Europe. The HOPE VI program in the U.S. is one popular example. Since its inception in 1992, HOPE VI has simultaneously displaced thousands of urban poor from their homes and neighborhoods, reduced their housing opportunities, and created and encouraged housing development for a more affluent population. Yet over the years, very few empirical studies have emerged that examine the place-based outcomes of HOPE VI within the context of gentrification. As such, important empirical questions remain unanswered. This study focuses on the geography of HOPE VI policy and gentrification in Chicago. The purpose of the study is to examine when, in what way, and to what magnitude the gentrification process has unfolded in public housing neighborhoods targeted by the HOPE VI program during the period 1990-2007. Socio-economic data from the U.S. Census and Geolytics; mortgage financing data from the FFIEC; building permits from the City of Chicago; and field surveys are utilized to create an assessment of gentrification. The findings show that the relationship between HOPE VI and gentrification is different in different areas of Chicago. HOPE VI is driving the gentrification process directly in some areas and indirectly in others. HOPE VI is the foundation that has made gentrification possible in public housing neighborhoods in Chicago. But HOPE VI is not the only driving force, as some areas have experienced gentrification even though they have not been cited for new housing and commercial development under HOPE VI. Latent market demand, incredibly profitable rent-gaps, excellent locations near shopping districts, and weakening insecurities among mortgage lenders are also solid forces working to expand the gentrification frontier in public housing neighborhoods.
    • Classification of Urban features using Airborne Hyperspectral Data

      Babu, Bharath Ganesh (2010-05-11)
      Accurate mapping and modeling of urban environments are critical for their efficient and successful management. Superior understanding of complex urban environments is made possible by using modern geospatial technologies. This research focuses on thematic classification of urban land use and land cover (LULC) using 248 bands of 2.0 meter resolution hyperspectral data acquired from an airborne imaging spectrometer (AISA+) on 24th July 2006 in and near Terre Haute, Indiana. Three distinct study areas including two commercial classes, two residential classes, and two urban parks/recreational classes were selected for classification and analysis. Four commonly used classification methods – maximum likelihood (ML), extraction and classification of homogeneous objects (ECHO), spectral angle mapper (SAM), and iterative self organizing data analysis (ISODATA) - were applied to each data set. Accuracy assessment was conducted and overall accuracies were compared between the twenty four resulting thematic maps. With the exception of SAM and ISODATA in a complex commercial area, all methods employed classified the designated urban features with more than 80% accuracy. The thematic classification from ECHO showed the best agreement with ground reference samples. The residential area with relatively homogeneous composition was classified consistently with highest accuracy by all four of the classification methods used. The average accuracy amongst the classifiers was 93.60% for this area. When individually observed, the complex recreational area (Deming Park) was classified with the highest accuracy by ECHO, with an accuracy of 96.80% and 96.10% Kappa. The average accuracy amongst all the classifiers was 92.07%. The commercial area with relatively high complexity was classified with the least accuracy by all classifiers. The lowest accuracy was achieved by SAM at 63.90% with 59.20% Kappa. This was also the lowest accuracy in the entire analysis. This study demonstrates the potential for using the visible and near infrared (VNIR) bands from AISA+ hyperspectral data in urban LULC classification. Based on their performance, the need for further research using ECHO and SAM is underscored. The importance incorporating imaging spectrometer data in high resolution urban feature mapping is emphasized.
    • Comparisons of Distributions and Isotopic Geochemistry of Benthic Foraminifera from Seep and Non-seep Environments, Offshore of Costa Rica

      Burkett, Ashley M. (2011-06-17)
      Vertical distribution patterns and stable isotopic geochemistry of benthic foraminifera labeled with CellTracker Green and stained with Rose Bengal were compared at sites of active methane seepage and adjacent non-seep habitats off the Pacific coast of Costa Rica. Sediment cores of bacterial mats from Costa Rica revealed vertical distribution patterns more similar to those seen previously in clam beds, suggesting increased levels of bioturbation compared to nonseep sites. Similar taxa were found at both seep and non-seep sites including: Chilostomella oolina, Uvigerina peregrina and hispida, Cibicides mckannai, and Cassidulina braziliensis. Within active methane seep habitats, elevated substrate such as carbonate rocks, and vestimentiferan tubeworms were examined for living foraminifera. Vestimentiferan tubeworms had highly variable numbers of attached epibenthic foraminifera, dominated by Cibicides wuellerstorfi and Carpenteria monticularis. Stable carbon isotopic comparisons between epibenthic foraminiferal species of Cibicides wuellerstorfi and the vestimentiferan tubeworms on which they reside revealed 10‰ to 30‰ differences between the foraminiferal carbonate and substrate, suggesting that the geochemical signatures of elevated epibenthics were not significantly influenced by the geochemical signature of the substrate on which they reside. This study finds no apparent methane influence on the foraminiferal calcite of elevated epibenthic foraminifera from the three active seep sites studied (Mound 11, Mound 12, and Jaco Scar). This may be because the elevated epibenthics were not exposed to seep-influenced fluids by inhabiting raised substrates. This study also provides a quantitative analysis of coiling directions in elevated epibenthic species at seeps, which has never previously been reported. Statistical analysis revealed that there were no significant differences in isotopic composition between sinstral (left)and dextral (right) coiling Cibicides wuellerstorfi. The results of this study suggest that coiling direction of elevated epibenthic oraminifera, such as Cibicides wuellerstorfi and Carpenteriamonticularis, is a result of biologic factors rather than environmental influences.
    • Dendroclimatic Reconstruction from Bald Cypress in Southwestern Indiana

      Van De Veer, Robin Lyn (2011-09-20)
      In the United States, bald cypress (Taxodium distichum) is generally recognized as an important component of the forested wetlands found in the Southwestern Coastal Plain and the Mississippi River Valley (which extends to the southern Midwest). The lifespan of this deciduous species is important not only commercially, but also in an ecological capacity. This study focuses mainly upon the role the tree plays in its environment and how it can be used as an indicator of climate through drought/flood signals in the rings. Bald cypress is a long-lived tree that can be over 1000 years old and is sensitive to climate and ground water hydrology. Because of these factors it is a favorable choice for dendrochronological study in the region. According to the International Tree-Ring Database, a chronology of the species is not well defined for southwestern Indiana. This research provides this missing information and creates the northern most bald cypress chronology in the Midwest. The study site is located in the extreme southwest of Indiana around Hovey Lake (a backwater lake of the Ohio River) about 10 miles south of Mount Vernon, Indiana. Samples were taken from trees near the shore, both on land and in the water.This study dated some trees to 1855. Analysis of the tree rings, climate data, and river discharge data revealed that bald cypress are not declining in southwestern Indiana. The rate of tree ring growth increases as PDSI does and the rate of river discharge does not seem to affect growth much at all. Even though this is the northernmost bald cypress chronology in the midwest and therefore should be stressed according to the theory of ecological amplitude, this chronology does not fall in the category with the highest series intercorrelation or mean sensitivity. The construction of the dam in 1975 has overwhelmed the climate signal in these trees and the trees continue to be suppressed due to the current water level.
    • THE ECOLOGY AND MORPHOLOGY OF DEEP-SEA BENTHIC FORAMINIFERA: THE AUSTRALIAN MARGIN AND EPIFAUNAL PORE CHARACTERISTICS

      Willingham, Jake (Indiana State University, 2014-05)
      The distribution and abundance patterns of modern benthic foraminifera are used by paleoceanographers to assess changes in ocean conditions over geologic time. Examination of modern foraminiferal analogs provides the means to determine how these single-celled protists record clues about ambient conditions in their morphology and abundance/distribution patterns. Abundance and vertical distribution patterns of deep-sea benthic foraminifera were examined along the South Australian Margin and Tasman Sea of Australia. This was one of the first studies to examine microhabitat preferences of living (Rose Bengal stained) deep-sea benthic foraminifera within the region. A total of 11 sediment cores were collected via multicorer. Substantial infaunal populations were found in these cores from a region characterized by well oxygenated bottom-water (> 4.0 ml/l) and organic-rich sediments (8-11% organic matter). This mesotrophic environment supported populations of Globocassidulina subglobosa, Valvulineria oblonga, Melonis barleeanum, Pullenia bulloides, Chilostomella oolina, and Hoeglundina elegans. Transport of organic-rich sediments via submarine canyons may account for increased food availability for deep-sea foraminifera in this region. A relationship between foraminiferal test morphology and ambient oxygen availability has been noted by a number of studies (e.g., Glock et al., 2011; Kuhnt et al., 2013). In an attempt to quantify the relationship between ambient oxygen availability and foraminiferal test pore characteristics, percentage and number of surface pores of 97 specimens of Cibicidoides wuellerstorfi and related taxa were examined from a variety of habitats along an oxygen gradient (0.04 – 6.20 ml/l). Using ArcGIS and high-resolution SEM images of living (Rose Bengal stained) specimens of Cibicidoides, percentages and number of pores on the tests were quantified. Surface pore percentage (SPORE) analyses of a standardized subset of penultimate and antepenultimate chambers plotted verses ambient bottom-water oxygen concentration yielded a negative correlation with an R2 value of 0.7291, p < 0.001. This SPORE approach provides an effective means to assess ancient bottom-water oxygen concentrations from epifaunal Cibicidoides.
    • THE ECOLOGY, BIOGEOCHEMISTRY AND PHYLOGENY OF METHANE SEEP AND NON-SEEP BENTHIC FORAMINIFERA FROM THE PACIFIC MARGIN

      Burkett, Ashley M. (Indiana State University, 2015-05)
      In an effort to understand the relationships between active methane seep and adjacent non-seep (inactive) populations of the deep-sea foraminifera Cibicidoides wuellerstorfi, a common paleo-indicator species, from methane seeps in the Pacific were analyzed and compared to one another for genetic similarities of small subunit rDNA (SSU rDNA) sequences. Pacific Ocean C. wuellerstorfi were also compared to those collected from other localities around the world (based on 18S gene available on Genbank, e.g., Schweizer et al., 2009). Results from this study revealed that C. wuellerstorfi living in seeps near Costa Rica and Hydrate Ridge are genetically similar to one another at the species level. Individuals collected from the same location that display opposite coiling directions (dextral and sinistral) had no species level genetic differences. Comparisons of specimens with genetic information available from Genbank (SSU rDNA) showed that Pacific individuals, collected for this study, are genetically similar to those previously analyzed from the North Atlantic and Antarctic. These observations provide strong evidence for the true cosmopolitan nature of C. wuellerstorfi and highlight the importance of understanding how these microscopic organisms are able to maintain sufficient genetic exchange to remain within the same species between seep and nonseep habitats and over global distances. Although organic matter degradation rates have been studied for some time, in situ rates of protoplasm degradation in deep-sea foraminiferal tests have been estimated based on laboratory experiments and sediment distribution patterns. Information regarding degradation rates of foraminiferal protoplasm is essential in the use of non-vital stains in identifying the amount and character of protoplasm in tests which remains the most commonly used method to assess living populations of benthic foraminifera (e.g., Murray and Bowser, 2000). In an effort to examine the retention potential of foraminiferal protoplasm on the deep seafloor 36 frozen, protoplasm filled Cibicidoides wuelllerstorfi were placed in natural sediments inside experimental containers and deployed on for 390 to 396 days. Despite oxygen-poor conditions (0.24 mL/L to 0.37 mL/L) that would be expected to promote preservation of organic matter, and experimental container protection from macro- and megafauna, 72% of deployed tests containing protoplasm were destroyed beyond recognition within 396 days. Of the 10 specimens (28%) recovered, 9 retained at least some protoplasm, but only 1 individual had the potential to be identified as living based on Rose Bengal staining techniques. However, in this specimen, protoplasm was clearly altered or missing in some chambers. The results of this study suggest that it is unlikely that many, if any, benthic foraminiferal specimens containing protoplasm terminated by freezing would be conservatively considered as recently living using Rose Bengal as an indicator of the extent and character of protoplasm within the test after 396 days or less exposed to in situ conditions in deep-seafloor habitats. After 390 to 396 days on the seafloor at Hydrate Ridge in the Pacific, eight artificial substrate experiments (hereafter referred to as SEA3 for Seafloor Epibenthic Attachment Cubes) were colonized by 1058 Cibicidoides wuellerstorfi. The presence of this species has been inferred as an indicator of well-oxygenated conditions, and recruitment of such large numbers in bottom-waters with low dissolved oxygen availability (0.24 to 0.37 mL/L) indicates that this taxon is not as limited by oxygen as previously thought. Clues about substrate preferences were also evident from the distribution of individuals on SEA3. For example, the wooden rod attached directly to the plastic mesh that was heavily colonized was devoid of any epibenthic foraminifera. Few studies have examined foraminiferal colonization of hard substrates in the deep-sea (e.g., Mullineaux, 1987), and to our knowledge no previous study has compared foraminiferal colonization of seep with non-seep substrates. Comparisons of abundance, size distribution, and isotopic biogeochemistry of living foraminifera colonizing experimental substrates revealed differences between seep and non-seep environments. SEA3 within active methane seep habitats at Hydrate Ridge contained significantly fewer (406 on four SEA3s a density of 44 #individuals/100 cm2) individuals compared with those in adjacent off-seep sites (594 on three SEA3s a density of 86 #individuals/100 cm2). An additional 58 individuals were on a SEA3 22, which may have experienced seep conditions despite being deployed as a nonseep experiment (density of 25 #individuals/100 cm2). This difference in abundance may be due to active seepage conditions, however, reduced foraminiferal abundances on SEA3s located at seeps resulted from increased predation and displacement by higher abundances of macro- and meiofauna observed at active seep locations. Stable carbon isotope values of benthic foraminifera from seep substrates ranged from 0.26‰ to -0.56‰ with an average of 0.03‰ while δ13C from off-seep substrates range from 0.39‰ to -0.26‰ with an average of 0.15‰. Statistical analyses indicate a significant difference between seep and non-seep δ13C. Stable oxygen isotopes of foraminiferal carbonate from seep substrates range from 2.70‰ to 2.03‰ with an average of 2.41‰ and 2.65‰ to 1.99‰ with an average of 2.39‰ at adjacent off-seep sites. These results provide some of the first information about epifaunal foraminiferal colonization potential at methane seeps and highlight the biogeochemical and ecological influences of seep habitats on C. wuellerstorfi.
    • Environmental Conditions of Green Valley Lake

      Bellamy, Jennifer (2011-03-16)
      Green Valley Lake, western Indiana, has experienced periodic inputs of acid mine drainage (AMD) from the abandoned Green Valley Coal Mine. The lake serves as a state fishing area, and AMD inputs may affect the aquatic ecosystem and human health. The purpose of this research is to determine to what extent the sediments in Green Valley Lake are acting as sinks for metals and if they may impact water quality. Water and bottom sediment samples were taken throughout the lake to evaluate spatial variability of contamination and to determine how the metal concentrations compared to Post Archean Average Shale (PAAS) background values and sediment quality guidelines (SQGs) values. Three cores were taken from the Northwest portion of the lake, where AMD enters via surface flow to evaluate temporal changes in contamination. Results indicate that water quality at Green Valley is acceptable, pH is slightly acidic (pH=6.4) near the locations of AMD input and increases to the east (pH=8.30). The northwest portion of Green Valley Lake is an eutrophic lake, based on its nutrient levels and Secchi disk measurements. Organic matter content, based on LOI, is higher in the older portion of the lake (7-33 wt %) due to the influence of vegetation surrounding the lake. Bottom sediment at Green Valley Lake are acting as a sink for metals and nutrients. Ni and Cd concentrations are above the sediment quality guidelines severe effect level, while Zn and Pb were above the probable effect level. Metals over the severe and probably effect levels should continue to be monitored in the sediments at Green Valley Lake to ensure that organisms are not being impacted.
    • Glacial/Interglacial Export Production in the Subantarctic South Pacific

      Adamic, Jessica (2010-07-22)
      Atmospheric CO2 varied considerably in the past; however, the mechanisms that drive this variability are poorly understood. CO2 is linked to marine primary productivity through the biological carbon pump (BCP), leading to hypotheses that past increases in BCP efficiency in areas such as the Southern Ocean may have contributed to glacial CO2 drawdown (Sarmiento & Toggweiler, 1984). Productivity has varied considerably in the past, but the extent, timing, and impacts remain poorly understood. The Subantarctic South Pacific is an area of the ocean that is crucial to the understanding of both glacial climate and paleo-export productivity. Unfortunately, few studies have investigated the central South Pacific because it is so remote. The sediment core MV0502-04JC was recovered from the Subantarctic South Pacific in February-March 2005 at 50°S. The results of this study will be compared with data from ODP Leg 189, Site 1171, also in the Subantarctic South Pacific. Data from these cores will be used to evaluate glacial/interglacial paleo-export production and terrigenous provenance using bulk sediment geochemical proxies, including detailed P geochemistry, P, Ba, and metal elemental ratios, and Baxs. The results of this research suggest each site has variable terrigenous provenance that may have relatively different Fe content. Export production at MV0502-4JC is invariant down core; however, Site 1171 does exhibit glacial/interglacial variations in export production.
    • Holocene Landscape Evolution of the Ohio River Valley from Knob Creek to Rosewood Bottom

      De Rego, Kathryn G. (2012-10-19)
      Rivers and floodplain environments have provided human settlements with resources for thousands of years. By understanding how rivers shape the land around them, we can use landforms to reconstruct ancient fluvial processes and to examine how they have conditioned the way humans interact with their environment. This study investigates the Lower Ohio River during the Holocene. During this period, Midwestern landscapes were adjusting to a variety of processes, including millennial-scale climate change involving the transition from a glacial to an interglacial environment. At the same time, Archaic hunter-gatherers adopted a settlement strategy that favored large river valleys. The cause of this shift has not been resolved. This study examined floodplain sedimentation and change along the Lower Ohio from Knob Creek to Rosewood Bottom through two different scales of analysis: the regional (geologic) scale and within local bottoms. A model of floodplain structure from Madison to Tell City, Indiana was created using a GIS and used to examine differences between geologic regions and Early and Late Holocene sediment. Swales were identified using a DEM, and depth, area, and perimeter-area ratio were used as proxies of their characteristics, which are correlated with backwater environments. Subsurface soil and sediment data were collected from a transect across Rosewood Bottom and within a paleochannel common to the study reach and used to reconstruct floodplain production within an individual bottom. Radiocarbon dates from geologic and archaeological contexts were used to examine Early and Late Holocene sedimentation rates. The Ohio River was active during the Early Holocene. It migrated rapidly and constructed most of the modern floodplain. In some areas, it was anabranching because resistant Pleistocene braid bars formed obstructions to flow that became islands. During the Late Holocene, deposition has been mainly characterized by overbank backwater/slackwater deposition in swales. There is not enough evidence to assign an exogenic cause to this phenomenon. Significant differences in floodplain structure between individual bottoms and regions, the influence of underlying Pleistocene gravels on river migration, and different dates for paleochannel abandonment are indicators of autogenic controls on the Ohio’s behavior and show that bottoms have independent histories. This study complements current models of environmental change for river basins in the Midwest, but it suggests that the stability of the floodplain be given more consideration when analyzing Archaic settlement strategy.