• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 40
  • 17
  • 1
  • Tagged with
  • 100
  • 35
  • 23
  • 19
  • 13
  • 12
  • 11
  • 11
  • 11
  • 11
  • 10
  • 10
  • 10
  • 10
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Fluorite: A Mineral of Importance in Midcontinental Prehistory

Boles, Steven L. 01 May 2012 (has links)
Crystalline minerals such as fluorite have been recovered from numerous prehistoric sites in the Midcontinent yet little research had previously been conducted concerning who used it and what they used it for. Ethnohistorical accounts inform us that crystalline minerals were of importance to American Indians during the Historic Period. These accounts are used to provide a basis for exploring the possible significance of fluorite to prehistoric peoples living near outcrops located along the lower Ohio River valley. In this thesis I analyze mainly prehistoric fluorite personal adornment items as well as similar items made from other locally available raw materials such as cannel coal and clay to gain an understanding of the importance of this colorful crystalline mineral to prehistoric inhabitants of the midcontinent.
32

EVIDENCE OF MARINE CONDITIONS IN THE UPPER PART OF THE DEGONIA SANDSTONE (ELVIRAN STAGE, CHESTERIAN SERIES) IN THE ILLINOIS BASIN

Larson, John Michael 01 December 2012 (has links)
The purpose of this study is to document and describe newly observed marine fossils from the upper part of the Degonia Sandstone and to infer the depositional setting of this horizon. Previous studies have shown that the Degonia Sandstone (Elviran Stage, Chesterian Series, Mississippian Subsystem) contains sedimentological evidence of several depositional environments (i.e. terrestrial, fluvial, nearshore deltaic, tidal, and possible marine zones); however, no body fossils had been observed. The only fossils identified in the Degonia are non-diagnostic trace fossils and Carboniferous plant remains such as Lepidodendron trunks and Stigmaria casts, suggesting a terrestrial environment. In 2010, Mary Seid and Joseph Devera of the Illinois State Geological Survey found marine fossils in the upper Degonia Sandstone in a stream bed located within the Wolf Creek Fault Zone. They associated these fossils with a marine environment, contradicting earlier assessments. Four study localities were found throughout the study, one each in the Gorham, Cobden, Glendale, and Raddle Quadrangles of southern Illinois. Sampling localities were found using geologic maps to locate the Degonia-Kinkaid contact, specifically areas where large stream valleys cut through the Kinkaid Formation and into the Degonia Sandstone throughout southern Illinois. The boundaries between the Degonia Sandstone and the overlying Kinkaid Formation were walked in order to find indicators of the marine zone (i.e. the presence of the shaly layer of the upper Degonia Sandstone). The reference section (the Gorham locality) contains the largest diversity of fossils and represents a storm deposit. The Cobden locality appears to contain a zone of dwarfed specimens and a zone of normal sized specimens, and represents a storm deposit. The Glendale locality is dominated by a single bivalve and represents brackish water conditions. The Raddle locality is non-fossiliferous, but was within the intertidal zone. The fauna identified by this study consists of four Phyla: Arthropoda, Brachiopoda, Bryozoa, and Mollusca. The only Arthropoda observed was a burrowing barnacle (Acrothoracica). The Brachiopoda observed consist of Diaphragmus nivosus, Orthotetes kaskaskiensis, Anthracospirifer occiduus, and Composita sp. The Bryozoa observed include Fenestrate and Trepostome. The Mollusca are the most diverse phyla observed, consisting of bivalves (Wilkingia walkeri, ?Edmondia sp., Aviculopecten winchelli, Promytilus illinoisensis, Myalina sp., ?Septimyalina sp., Myalinella meeki, ?Sphenotus monroensis, and four species of unknown bivalves), cephalopods (Reticycloceras sp., Endolobus sp., Liroceras sp., Metacoceras sp., and Domatoceras sp.), and gastropods (Euconospira sturgeoni, ?Eotrochus cf. marigoldensis, and an unknown gastropod). Other fossils observed were crinoid stem molds and plant material. The characterization of invertebrate fossils occurring in the upper Degonia supports the previous suggested marine sedimentological features of the Degonia Sandstone.
33

Afterimages of Kincaid Mounds

Pursell, Corin Clayton O'Brien 01 August 2016 (has links)
This research will address how the monumental organization of Kincaid Mounds was put together through time. The measurable variability in the potential performative presentation of the mounds and structures of Kincaid will be treated as an archaeological dataset for the exploration of social change. This dataset will emphasize the topological relationships among earthworks, structures, and the ancient Native Americans living within and actively constructing the site and their society. The dynamics of change in the public presentation of these earthworks will relate to public practice and changing political strategies, a local history indicative of Kincaid’s internal social processes and political trajectory in the broader Ohio Valley and Mississippian culture.
34

A SEISMIC REFLECTION STUDY OF A MISSISSIPPIAN MUD-MOUND NEAR ADEN, ILLINOIS

Holguin Macuster, Ruben 01 August 2018 (has links)
In 2011 and 2012 a Vibroseis™ seismic reflection survey, consisting of one westeast and one north-south seismic reflection profile, was conducted near the community of Aden (Hamilton County), Illinois, for hydrocarbon exploration purposes. Previous interpretations of the west-east seismic line (Ranaweera, 2015), as well as drill cuttings (Cantrell, 2011) from a nearby well (Webb #1), indicated the existence of a mud-mound within the Ullin Limestone. This thesis studied the shape and dimensions, as well as the seismic velocity properties, of the Aden mud-mound by re-processing and interpreting the Aden seismic reflection data. The interpretation process was aided by constructing two-dimensional synthetic seismograms from well log data from the nearby Broughton and Johnsonville oil fields, which are known locations of Waulsortian mud-mounds similar to the one inferred to exist at Aden. The results of this investigation indicate that the Aden mudmound has a longitudinal extent of approximately 0.6 miles (0.97 km) wide across the west-east ADEN #1 profile. From north-to-south on the ADEN #2 profile, the feature is approximately 0.7 miles (1.13 km) long. The geologic feature is located within the Ullin Limestone (Lower Mississippian) and is only manifested by the draping of younger strata overlying the mud-mound as observed on the seismic reflection images. Results from the 2D synthetic seismograms indicate that the seismic reflections generated across the known mud-mounds at Broughton and Johnsonville are similar to the seismic reflections seen at the location of the interpreted mud-mound on the Aden seismic reflection data. The presence of the Aden mud-mound is inferred by the draping of overlying strata above the mud-mound. This is interpreted to be caused by the increase in stratigraphic relief at the top of the Ullin, which becomes thicker at the mud-mound locations. Geologic and well log data from drill holes at Aden revealed that the interpreted Aden mud-mound formed in the Harrodsburg Member of the Ullin Limestone. The Harrodsburg is approximately 90 feet (27 meters) thick at Aden but becomes thicker at the location Webb #1 (up to 152 feet) where the mud-mound is located, indicating that the Aden mud-mound is at least 152 feet thick, when measured from the base of the Harrodsburg Member. A study of Root-Mean-Squared (RMS) and interval velocities, derived from sonic and pseudo-sonic log data from wells from the Aden, Broughton, and Johnsonville locations, indicated that RMS and interval velocities from the upper member (Harrodsburg Member) of the Ullin Limestone are higher than RMS and interval velocities present in the lower member (Ramp Creek Member) of the Ullin. Stacking velocities derived from the Aden seismic reflection data matched the RMS velocity values derived from sonic log data from drill holes at Aden with percent differences of less than 5%. This study indicates that stacking velocities at this location are accurate enough (within approximately 5%) to perform velocity studies when well log data from drill holes are not available. Additionally, there were no significant variations in stacking velocity profiles in the Ullin Limestone atthe Aden mud-mound location when compared to stacking velocity profiles derived at CMP locations away from the mud-mound. Likewise, there were no significant variations between RMS and Interval velocity profiles of the Ullin Limestone, derived from wells that were drilled into mud-mound locations at Aden, Broughton, and Johnsonville, and RMS and interval velocity profiles derived from wells that were drilled away from the mud-mound locations. The conclusion of this study is that RMS and interval velocity profiles, as well as stacking velocity profiles from seismic reflection data, are not good indicators for pinpointing the existence and location of carbonate mud-mounds. The best method to identify such carbonate structures is by interpreting their structure observed on seismic reflection records, including the draping effect on shallow reflections above the mudmound as observed in the recorded seismic reflection data, and by analyzing drill cuttings if available.
35

Reservoir analysis of the compartmentalized Mississippian ages Spivey-Grabs field, south central Kansas

Stevens, Logan January 1900 (has links)
Master of Science / Geology / Matthew W. Totten / Mississippian chert reservoirs, also known as chat reservoirs among the mid-continent in Kansas and northern Oklahoma, produce an abundant amount of hydrocarbons. Since the 1920s, chat reservoirs in Kansas have yielded over 380 million bbl of oil and 2.3 tcf of natural gas. The largest Mississippian field in south-central Kansas is the Spivey-Grabs, which spans Kingman and Harper Counties. Development of the Spivey-Grabs Mississippian reservoir, and continued production within the field, has been compromised by compartmentalization within the field, resulting in unpredictable producing rates. Previous research has investigated the differences of the fluids within the separate compartments (Evans, 2011; Kwasny, 2015), and identified the existence of at least two oil types of differing viscosity (Kwasny, 2015). The objective of this research was to determine whether the compartmentalization of the reservoir is controlled by the different lithologic characteristics between the various compartments. This was accomplished by examining drill cuttings under binocular microscope, under a petrographic microscope using digital imaging software, and under the high magnification of a scanning electron microscope. Calculated rock porosity from ImageJ software showed variation among the wells selected for this study; but the porosity variation does not correlate with differences in fluid viscosity that was previously observed, i.e. heavy and light viscosity oils (Kwasny, 2015). Heavy oils were seen in wells that had both higher and lower porosity values, and the same is true for the distribution of light oils. This suggested that fluid viscosity is the major controlling factor in compartmentalization in the Spivey-Grabs and not rock properties.
36

Interactions with the Incorporeal in the Mississippian and Ancestral Puebloan Worlds

January 2014 (has links)
abstract: This research explores how people's relationships with the spirits of the dead are embedded in political histories. It addresses the ways in which certain spirits were integral "inhabitants" of two social environments with disparate political traditions. Using the prehistoric mortuary record, I investigate the spirits and their involvement in socio-political affairs in the Prehispanic American Southeast and Southwest. Foremost, I construct a framework to characterize particular social identities for the spirits. Ancestors are select, potent beings who are capable of wielding considerable agency. Ancestral spirits are generic beings who are infrequently active among the living and who can exercise agency only in specific contexts. Anonymous groups of spirits are collectives who exercise little to no agency. I then examine the performance of mortuary ritual to recognize these social identities in the archaeological record. Multivariate analyses evaluate how particular ritual actions memorialized the dead. They concentrate on treatment of the body, construction of burial features, inclusion of material accompaniments, and the spaces of ritual action. Each analysis characterizes the social memories that ritual acts shaped for the spirits. When possible, I supplement analysis of archaeological data with ethnohistoric and ethnographic information. Finally, I compile the memories to describe the social identities for the spirits of the dead. In this study, I examine the identities surrounding the spirits in both a Mississippian period settlement on the Georgia coast and in several Protohistoric era Zuni towns in the northern Southwest. Results indicate that ancestors were powerful members of political factions in coastal Mississippian communities. In contrast, ancestral spirits and collectives of long-dead were custodians of group histories in Zuni communities. I contend that these different spirits were rooted in political traditions of competition. Mississippian ancestors were influential agents on cultural landscapes filled with contestation over social power. Puebloan ancestral spirits were keepers of histories on landscapes where power relations were masked, and where new kinds of communities were coalescing. This study demonstrates that the spirits of the dead are important to anthropological understandings of socio-political trajectories. The spirits are at the heart of the ways in which history influences and determines politics. / Dissertation/Thesis / Ph.D. Anthropology 2014
37

Investigation into the importance of geochemical and pore structural heterogeneities for shale gas reservoir evaluation

Ross, Daniel John Kerridge 05 1900 (has links)
An investigation of shale pore structure and compositional/geochemical heterogeneities has been undertaken to elucidate the controls upon gas capacities of potential shale gas reservoirs in northeastern British Columbia, western Canada. Methane sorption isotherms, pore structure and surface area data indicate a complex interrelationship of total organic carbon (TOC) content, mineral matter and thermal maturity affect gas sorption characteristics of Devonian- Mississippian (D- M) and Jurassic strata. Methane and carbon dioxide sorption capacities of D- M shales increase with TOC content, due to the microporous nature of the organic matter. Clay mineral phases arealso capable of sorbing gas to their internal structure; hence D- M shales which are both TOC- and clay-rich have the largest micropore volumes and sorption capacities on a dry basis. Jurassic shales, which are invariably less thermally mature than D- M shales, do not have micropore volumes which correlate with TOC. The covariance of methane sorption capacity with TOC, independent of micropore volume, indicates a solute gas contribution (within matrix bituminite) to the total gas capacity. On a wt% TOC basis, D-M shales sorb more gas than Jurassic shales: a result of thermal-maturation induced, structural transformation of the D- M organic fraction. Organic-rich D- M strata are considered to be excellent candidates for gas shales in Western Canada. These strata have TOC contents ranging between 1-5.7 wt%, thermal maturities into the dry-gas region, and thicknesses in places of over 1000 m. Total gas capacity estimates range between 60 and 600 bcf/section where a substantial percentage of the gas capacity is free gas, due to high reservoir temperatures and pressures. Inorganic material influences modal pore size, total porosity and sorption characteristics of D-M shales. Carbonate-rich samples often have lower organic carbon contents (oxic deposition) and porosity, hence potentially lower sorbed and free-gas capacities. Highly mature Devonian shales are both silica and TOC-rich (up to 85% quartz and 5 wt% TOC) and as such, deemed excellent potential shale gas reservoirs because they are both brittle (fracable), and gas-charged. However, quartz-rich Devonian shales display tight-rock characteristics, with poorly developed fabric, small median pore diameters and low permeabilities. Hence potential `frac-zones' will require an increased density of hydraulic fracture networks for optimum gas production. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
38

A GIS Approach to Understanding Mississippian Settlement Patterns in the Central Illinois River Valley

Swoveland, Kayla Jan 07 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Geographic Information Science (GIS) technologies have helped to further the research of archaeologists almost since the inception of the field. Archaeologists have long made observations rooted in what would become GIS, but it wasn’t until the early 21st century that science was able to back up these observations. From the seemingly simple task of organizing and storing spatial data to more robust statistical and spatial calculations, GIS has quickly become a valuable tool used by archeologists to better understand past populations. This research applied GIS to help understand the regional distribution of settlement locations from the Mississippian Period (AD 1050-1450) in the central Illinois River Valley (CIRV) of west-central Illinois. Settlement distribution was examined in two contexts, first in the context of larger, more “metropolitan” site placement in relation to smaller, more transitory sites. Secondly, site distribution was examined to see what, if any, pattern existed between site placement and a set of ecological factors. The results found that while smaller sites were prevalent around many of the larger sites, a few metropolitan sites did have a larger number of smaller sites surrounding them, supporting the idea of certain Mississippian sites serving as hubs. Additionally, it was demonstrated that several different types of GIS based analyses were particularly effective in helping to identify these patterns, thus solidifying and improving the role of GIS in the field of archaeology.
39

Changes in occupation at Lyon's Bluff (22OK520)

James, Thomas Reuben 07 August 2010 (has links)
Lyon’s Bluff is an archaeological site covering approximately 25 hectares in Oktibbeha County, MS. Richard Marshall proposed that the site can be divided into two occupations – the eastern area, occupied during the Mississippian period (A.D. 1000- 1540); and the western area, occupied during the Protohistoric period (A.D. 1540-1750). Starting in 1935 several archaeological excavations have taken place at Lyon’s Bluff, but the work has always focused on the eastern area of the site. To test Marshall’s proposal, a series of shovel tests was dug over the site, and 14 one-m2 excavation units were placed on purported house mounds in the western area. Eight of the fourteen excavation units were proven to be on house mounds, with the others being on natural rises. Typological analysis of the artifacts collected showed that the east-west division is speculative and that the entire site was occupied throughout the course of its history.
40

Sequence Stratigraphy and Paleoecology of the Late Mississippian Little Stone Gap Member in the Appalachians of West Virginia

Oyewumi, Adeola Adedoyin 12 June 2012 (has links)
The upper Mississippian (Chesterian) Little Stone Gap Member of the Hinton Formation in southern West Virginia was evaluated for its lithofacies and faunal composition. Petrographic and multivariate analyses were used to provide a better understanding of the ecological factors and sequence stratigraphic processes that controlled taxa ordinations and spatiotemporal shifts in facies. Six carbonate and three siliciclastic facies occur within the study interval and these facies stack into two distinct parasequence types. Siliciclastic facies were deposited in continental, low-energy lagoonal and marginal marine environments. Carbonate facies record variable energy conditions in lagoonal, shoal, shoal flank and open marine settings. Parasequence stacking patterns are interpreted as resulting from regional fifth-order glacioeustatic sea-level changes consistent with established age constraints for fourth-order sequences. Detrended Correspondence Analysis (DCA) of paleontological bulk samples produced similar differentiation of habitats into carbonates and siliciclastics thereby demonstrating the importance of interpreting ordination patterns within a facies framework. The combined DCA analysis of samples and taxa indicates that bryozoans, crinoids and rugose corals preferentially occur in carbonate facies whereas brachiopods, the most dominant taxon, are abundant in both. Results suggest the presence of significant paleoenvironmental gradients in fossil associations that correlates to changes in hydrodynamic conditions and substrate composition across the depositional system. / Master of Science

Page generated in 0.0561 seconds