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  • 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.
1

Petrologic analysis of the Mississinewa Member of the Wabash Formation and the effect of reef proximity on interreef sedimentation

Owens, Robert N. 03 June 2011 (has links)
There is no abstract available for this thesis.
2

Age and origin of the sedimentary dikes of the Pipe Creek Junior (Silurian) Reef, Grant County, Indiana

Burns, Danny E. 03 June 2011 (has links)
Sedimentary dikes at the Pipe Creek Junior Quarry were found to fill fractures formed by compaction and rotation of the reef flank beds and by regional stresses of less certain origin. A sequence of fracturing events has been established as well as a sequence for the emplacement of dike materials. Most of the carbonate dikes are found to be of Cayugan (Silurian) age, although some of the las carbonates are shown to be of Devonian age due to the presence of rounded detrital quartz grains within them. All of the quartz arenite dikes are found to be of Devonian age and are divided into two major groups: older white arenites and younger brown arenites. The two types of arenties have different characteristics and were deposited under different conditions.The arenites of Pipe Creek Junior Quarry were found to be similar to the arenites of the Bluffton Quarry which are also fracture fillings in Silurian reef rock. Other Devonian sand bodies are compared to the fracture filling and, although they are not identical, they show a similarity in materials and a pattern of environment and deposition that point to a northwestern source for all of the rounded quartz studied in this work. Environmental analysis of the quartz grains indicates a litoral mode of transport and sorting for most of the samples with an ecolian mode present in the sands outside the reef area and as a minor component for some of the younger sands within the reef area.A map of the glaciated quarry surface has been prepared for the purposes of this work and to preserve relationships that are constantly being removed by quarrying of the reef flank beds.
3

A depositional model for the Muncie Esker, East-Central Indiana

Terrell, Mark A. January 1997 (has links)
The Muncie esker, a glaciofluvial ridged system, consists of three sharp-crested esker segments in the proximal and central sections, and a broad=crested, fan shaped distal segment. Grain size ranged from clay to boulders, although a larger presence of coarser material with high standard deviation values occurs in the proximal and central segments, while higher concentrations of finer sediment, primarily sand, exists in the distal segment. Field mapping and description included its geomorphic expression, stratigraphic relationships that consisted of facies identification, sedimentary structure , and paleocurrent direction. Sedimentological parameters, including downesker trends in grain size, sorting, a fractal analysis of grain size persistence, and clast roundness, was also investigated.The interpretation of the results provided us with detailed information allowing us to formulate a specific model of esker genesis. The depositional model consists primarily of nearly continuous, contemporaneous subglacial deposition that reulted in the formation of the proximal and central esker segments, and time-transgressive sedimentation, containing interlayered and randomly distributed ice rafted debris, in the form of a subaqueous delta that prograded beyond the ice-margin, forming the distal esker segment. Early stage deposition consisted of bed load transport from moderate flow velocities within a preglacial bedrock valley that served as an R-channel for preliminary subglacial meltwater drainage. Intermediate stage formation consisted of subglacial sedimentation from a hyperconcentrated deforming bed, induced by an outburst flood, and distal deltaic sedimentation as the subglacial flood discharged beyond the ice margin into an ice-marginal lake. Late stage deposition arises from bed load sedimentation of moderate fluvial activity reworking the upper portions of the hyperconcentrated flow deposits and upper deltaic facies. The finality of esker formation concluded with the ablation of the subglacial tunnel roof, sending a supraglacial debris flow that conformably covers the proximal and central esker segments in the form of a diamicton drape. / Department of Geology
4

Electrical resistivity methods in the unconsolidated glacial sediments of Delaware County, Indiana

May, Suzette Kimball 03 June 2011 (has links)
Delaware County, Indiana, is characterized by its glacial sediments and topography. With increasing development, the need for reliable, cost-effective subsurface surveying methods becomes more important. This thesis explores the possibilities of electrical resistivity methodology. Fifty survey sites were established on a one-mile grid over twenty square miles west of Muncie, Indiana. Three electrode arrays were tested, Wenner, Lee Partitioning, and Schlumberger, and the data interpreted by three methods, logarithmic curve matching, Moore's cumulative method, and Barnes' layer method.No one method proved to be completely accurate and reliable. Used in conjunction, however, data from the three are consistent and the techniques are viable measures for the analysis of heterogeneous glacial sediments. Additionally, apparent resistivity values which characterize the particular sediments in the study area were established and several pervasive stratigraphic units were defined.Ball State UniversityMuncie, IN 57406
5

GIS analysis of the trapping efficiency of vegetative filter strips in the Bear Creek watershed

Maracini, Kelly A. January 1997 (has links)
This project uses a Geographic Information System (GIS) as a tool for estimating soil erosion on a watershed scale. A new and key tool for managing ecosystems in North America are resource management plans based on watershed areas. Watershed management plans are a response to widespread concern about the cumulative effects of nonpoint source pollution (such as agriculture pollution) on water resource quality.The primary objective of this project was to develop a method using GIS to estimate the annual gross erosion for each of the watersheds. Sediment delivery was calculated within each of the subwatersheds of Bear Creek, and the amount of sediment that potentially could be trapped by vegetative filter strips in each watershed was determined. The area that was used for the study site is the Upper Bear Creek watershed. The Bear Creek watershed is a subwatershed of the Loblolly watershed in Jay County, Indiana.The analysis determined that 99% of sediment was contributed from cropland. When vegetative filter strips were modeled, the sediment delivered to a load cell was substantially reduced. Cropland area required for vegetative filter strips would be 2.3% for the whole watershed. / Department of Natural Resources and Environmental Management

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