STRATA
STRATA, the STudent Research, Academic, and Talent Archive, is a collection of selected Fort Lewis College student work, including undergraduate research, senior seminar papers, published works, conference presentations, and other creative and artistic projects. Search by name, subject, title, or academic department.
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- Shallow Seismic Analysis of Bedrock Beneath Alluvium and Glacial Outwash: La Plata River Terraces, Southwestern Colorado
- A shallow seismic analysis was conducted to image bedrock depth and geomorphology beneath Neogene alluvium and glacial outwash deposits along the La Plata River in southwestern Colorado. A main objective was to constrain terrace thickness to assist in aquifer assessments and to constrain the geomorphic evolution of the area. Refraction analysis techniques were used to image the unconsolidated sediment to bedrock interface by examining the velocity contrast in regards to a two layer model. Sources of error examined include the effects of ground roll, air-coupled waves, data collection pitfalls, ground saturation, spatial and temporal aliasing, and processing error. In addition to defining the base of the terrace sediments, deeper anomalies were detected that could represent bedrock structures or buried fluvial channels. These anomalies occur over short horizontal distances (10-50m) indicating significant variability at the base of the terrace sediments. Regional well data constraints suggest unconsolidated sediment thickness of 6-20 meters which varies with this study's 3-13 meters projected thickness. Sediment thickness was applied to determine aquifer potential estimates, revealing 400-1000 acre feet of obtainable water within the glacial outwash terrace. The applied methods of this study demonstrate the utility of shallow seismic techniques to improve our understanding of terrace morphology and provide constraints for modeling shallow unconfined aquifers.
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- Shear Sense of the Fall Creek Shear Zone, Vallecito Creek Area, La Plata County, Colorado
- A portion of the contact between the 1.8 Ga Irving Formation and the younger Vallecito Conglomerate, including the Fall Creek Conglomerate, is recognized as a fault (Gonzales, 1988). However, previous studies have found conflicting evidence for its shear sense: Gonzales (1988) found outcrop-scale evidence for west-side-up shear, whereas Zinsser (2006) found thin-section-scale evidence for east-side-up shear. In order to resolve these conflicting observations, a systematic field- and microscopic-scale study of shear sense along the two-mile-long exposure of the shear zone has been undertaken. The Irving Formation, a 1.8 Ga metabasalt, forms a significant part of the crystalline basement of the modern San Juan Mountains and represents the early arc accretion of the proto-continent Laurentia. The younger Vallecito Conglomerate and its local basal facies, the Fall Creek Conglomerate, are metaconglomerates interpreted to have been deposited after 1.7 Ga (Jones et al., 2008). The Vallecito Conglomerate lies in stratigraphic or fault contact with the Irving Formation in several outcrop locations, including the study area near Vallecito Creek and Fall Creek in La Plata County, Colorado. The basal facies of the Vallecito, the Fall Creek Conglomerate, is interpreted as a metamorphosed, short-fluvial-system deposit and makes up most of the sheared rock at this location (Gonzales, 1988). The shear zone is highly foliated along a nearly vertical, approximately north-south plane. Some foliation surfaces contain lineation from aligned minerals, also with a nearly vertical plunge. Within the Fall Creek Conglomerate, there is a gradational transition from the quartz-rich pebbles and cobbles of the Vallecito Conglomerate on the east side, into the mafic, fine-grained Irving Formation on the west. Outcrop and thin section analysis from this area has shown asymmetric clasts of quartz, epidote and hornblende indicating a shear sense of west-side-up relative movement, confirming the interpretation of Gonzales (1988). This shear sense is consistent with the interpreted structural relationship, in which the Fall Creek and Vallecito Conglomerates were deposited (unconformably) upon the Irving Formation and subsequent faulting elevated the older Irving above the younger conglomerates. The overall mineral assemblage includes primarily biotite, hornblende/actinolite, magnetite, epidote, chlorite, and quartz and reveals that the ductile movement took place under mid- to upper greenschist facies conditions. A range of elongate crystal orientations indicates that most of the shear zone deformed before the growth of these crystals, while other zones include hornblende and biotite oriented in the direction of foliation. There is no local evidence for reactivation of the shear zone at temperatures lower than middle greenschist facies.
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- Shredding the Gnar and Your Body: An Analysis of Ski Injuries in the 2014-2015 Season
- According to the National Ski Areas Association over 600,000 documented injuries occur at ski resorts in the United States each year. The goal of this study was to analyze how these injuries sort out among age, skiing ability, area of body affected, and injury type when compared to gender. 600 subjects were included in the data. The subjects were all injured and had made contact with the Taos Ski Valley ski patrol during the 2014-15 ski season. A chi-square test was the primary method of statistical analysis. The results showed that men experienced 54% more injuries overall than women, however, women had a higher number of lower extremity injuries than men (X2 (6, N=600) = 11.36, p=0.078. Both men and women in the 31-50 age range suffered more injuries than the other age ranges recorded X2 (5, N=597) = 9.45, p=0.092. The percentage of beginner/intermediate skier injuries was 2.5 times that of advanced skiers, X2 (2, N=595) = 33.61, p=0.000. The results showed that men endured a higher percentage of fractures/dislocations compared to women who had a greater percentage of sprains/strains, X2 (8, N=600) = 24.23, p=0.002. The hypothesis was accepted in regard to men experiencing a greater number of injuries overall and women suffering a higher number of lower extremity injuries. Based on the results of this study, and similar research referenced, skiers of all ages and ability levels could help reduce the number of injuries overall by engaging in more thorough preparation for this demanding sport. For future research, a larger sampling size including more skiing regions and larger resorts would be conducive as well as further investigation into the role of equipment in snow sport injury.
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- Sifting Through Time: Screening in Today's Archaeology
- In the recent past, there have been many advances in archaeological techniques and technology. One piece of technology that has not been changed is the screen or sifter. While there are multiple sizes and types of sifters, the basic technology behind it has not changed. The techniques and use of screening, however, have changed. In modern archaeology, there is a divide between academic archaeology and public archaeology (Cultural Resource Management). Recovery mode is the method in which an archaeologist recovers artifacts from a site. In academia, during excavation the preferred method of artifact recovery is screening. In public archaeology, recovery methods vary due to restrictions on time and funding. This research focuses on the reasons why academic and public archaeology vary in recovery mode. Using examples from various manuals of archaeological technique and journal articles the reasons are explored. Along with researching the divide in screening techniques, this study researches the value of screening using ceramic data collected at the Pigg Site in southwestern Colorado, a Pueblo II/III site. Factors such as artifact count and information attained from ceramic artifacts are discussed and measured. The aim of this paper is to open a dialogue in archaeology about recovery methods and the divided use of these methods.
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- Similar Stimuli and Misattribution
- In this study I investigated the memory error known as misattribution. I examined how one may unconsciously transfer aspects of one memory into another. More specifically I looked at the occurrence of misattribution when there are similar details in the presented stimuli (two memories). Will those presented with similar details display misattribution more than those presented with non-similar details? Similar to a previous study, half of the participants were given two stories with the main character having the same name, while the other half received stories containing different names. Participants were then asked to perform a recognition task regarding the details from the stories. The results indicate that there was not a significant difference between the two groups. There was a small difference in the mean scores between the two groups, with those in the group with the same name actually scoring slightly higher. This reveals that the results are due to chance. The results indicate that misattribution will not occur when participants are asked to recognize details from a short memory that is two paragraphs in length.
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- Similar Stimuli and Misattribution
- Poster presentation on the occurrence of misattribution when there are similar details in presented stimuli (two memories).
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- Sleeping Lion
- Photograph by Dimitra Schreiber from Fall 2013 - Winter 2014 issue of Images
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- Small Scale Retrograde Reaction Textures: Implications for Pressure and Temperature Evolution Northeastern Vermont | USA
- The Victory Pluton, a Devonian aged granite in northeastern Vermont, is thought to have intruded during movement on the Monroe Fault. Metamorphic rocks in the contact aureole provide clues about the pressure and temperature changes during intrusion of the magma. The goal of this research project is to observe the metamorphic reaction textures within one sample from the eastern (uplifted) side of the fault to examine the temperature and pressure changes that occurred during metamorphism. Five sites throughout the thin section were analyzed using a petrographic microscope and scanning electron microscope. There are two dominant porphyroblasts within the sample, garnet and cordierite. Sites 1-4 possess garnet porphyroblasts with cordierite and ilmenite inclusions and biotite and fibrolite surrounding the crystal in the pressure shadow. Site 5 contains cordierite porphyroblasts with plagioclase and biotite inclusions. Biotite and sillimanite are also contained in the pressure shadow surrounding the cordierite. While the porphyroblasts vary between garnet and cordierite from each site, the minerals textures suggest that garnet and cordierite were consumed while biotite and sillimanite grew. This reaction takes place at temperatures between 600 and 800 degrees Celsius and pressures between 2 and 5 kilobars. This reaction is driven by either decreasing temperatures or increasing pressures. These reactions are consistent with cooling after the pluton intruded, or burial of the rocks after pluton intrusion, or both.
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- Smoke Escapes
- Poem by Kinsey Wheatley from Fall 2012 - Winter 2013 issue of Images.
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- Social Networking: A Buffer Against Death Anxiety
- This study examined effects of mortality salience (MS) on social networking usage. Participants logged onto Facebook after writing about either death (MS) or dental pain. MS increased Facebook usage in terms of sites visited and future use predictions, showing that social networking functions as a buffer against death anxiety.
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- Soil study in a high elevation meadow near Snowdon Peak, Colorado
- This field study is located among the Southern San Juan Mountains in a high alpine environment. Three high elevation soil trenches were dug in order to extract information on sediment maturity and mineralogy of the research area. The water table in this zone is high and shares similar characteristics with the adjacent valley that can be classified as a fen. After collecting the soil samples for X-ray diffraction (XRD), it was recognized that an iron rich chlorite was present as well as quartz. The lack of organic material and clays suggest immature sediments. The blue coloration in the minimal clay content suggests anoxia. Collectively, this data alongside glacial striations carved into the Uncompahgre Quartzite Bedrock 1.25 Km north and 600 ft. higher in elevation suggests soils that could be classified as inceptisols. Less than .1 km from the study area alpine fens and lakes are present. Evidence derived from this field study suggests that previous soils were likely removed as a result of glacial activity during the Last Glacial Maximum. The swallets along the Northwestern fault boundary are an active draining mechanism and has likely been draining this valley since the last glacial maximum.
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- Solar Heat to Chemical Fuels
- The solar thermochemical production of hydrogen from water via a metal oxide cycle has provided great interest to the greatly insolated "sunbelt" regions of the southwestern United States and other developing regions of the world. Used in conjunction, concentrated solar heat can generate enough thermal energy to split the water molecule into its constituent hydrogen and oxygen using a zinc catalyst. Hydrogen, an energy vector can be produced with virtually zero net greenhouse emissions. This method of hydrogen production provides an intriguing insight into the future of chemical fuels and a cleaner energy future.