Department of Earth and Environmental Sciences

Persistent link for this communityhttps://hdl.handle.net/11299/212255

Environmental Science provides an overview of how science affects our environment. We focus on interactions between the solid Earth, its water, its air and its living organisms, and on dynamic, interdependent relationships between these four components. Earth and environmental scientists also consider how these relationships produce environmental change at different timescales. To do this, they combine knowledge, models and methods drawn from geology, biology, physics and chemistry. We also strive to understand past and present environmental processes so that reliable and scientifically based predictions can be made about the future.

Learn more at the Department of Earth and Environmental Sciences website.

Historical note: The Department of Geology was formed in 1950. In 1999 it became the Department of Geological Sciences. It kept that name until 2014, when it became the Department of Earth and Environmental Sciences.

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Browsing Department of Earth and Environmental Sciences by Type "Scholarly Text or Essay"

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    Development of a Copper-Nickel Industry in Northeastern Minnesota
    (1973-06) Saremba, Scott P
    Many factors and problems must be considered in the developing of a copper-nickel operation in the Duluth Complex of Northeastern Minnesota. Exploration studies in the Complex reveal large volumes of low-grade copper-nickel sulfides (65 billion tons) and relatively small quantities of high-grade material (in excess of one percent). The Duluth Complex has not been extensibly explored and large areas of the Complex remain to be studied for their mineral potential. The known copper-nickel deposits are in a favorable geographic location with respect to labor, transportation, electrical power, water resources, and needed ancillary operations. The known deposits are found along the base of the Duluth Gabbro, and it is believed that most of the mineralized material will be found along the base. The deposits are found on Federal, state, and private lands, and therefore, the acquisition of these lands to prospect and permit to mine is different in each case. Federal and state mineral rights are leased, but private mineral interests may be bought or sold. Mineral land environment must be considered, as exploration and mining will affect the land, water, and air in varying degrees. Exploration can be carried out with no lasting effect on the environment, but actual mining can produce lasting effects. The degree to which the environment will be affected will depend on advanced planning, statutory authority to regulate the impact of mining on the environment, mineland reclamation plans, and the extraction method used or not used. Because most of the copper-nickel deposits are within the Superior National Forest, prospecting and mining must follow the rules and regulations of the Forest Service and Department of Interior. Part of the Duluth Gabbro is in the Boundary Waters Canoe Area, but a court decision has terminated all attempts to explore the area and prevents future mining in the BWGA. Public opinion is against mining in the BWCA because of the effects that are feared it will have on the wilderness character. Although, geological studies could be carried out without having any detrimental effect on the area. At the present, there is an oversupply of copper and nickel on the world market, but a projected demand is expected to substantially exceed supply in the future (10-20 years). Therefore, the United States will become more and more reliant on foreign sources. The prediction clearly indicates that additional U.S. copper-nickel operations will be needed. This report indicates the probability of success of such an operation in Northeastern Minnesota.
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    Geologic Processes and Hazards in High-Relief Terrain
    (1977-07) Berner, Heinz
    The content of this paper summarizes the principles of glacial processes and some aspects of mass movement in mountain regions such as the Alps. Especially avalanche formation and protective measures as practiced in Switzerland shall be discussed. The purpose of this report is to review some surficial geologic processes in high-relief terrain and see how they affect human developments and activities. It is thus, too, a practical exercise in environmental geology, particularly as it relates to land use planning. Furthermore, it is a library research paper required for graduation.
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    Glacial History of the Late Wisconsinan Des Moines Lobe in Minnesota: Geomorphic, Lithologic and Stratigraphic Evidence for Two Advances
    (2024-05) Arends, Heather E
    Continental ice sheets play a significant role in the Earth’s climatic system. Reconstructing the growth and decay of the Laurentide Ice Sheet during the Last Glacial Maximum betters our understanding of how ice sheets respond to climate change and contribute to rising global sea levels. The southwestern margin of the Laurentide Ice Sheet formed discrete terrestrial lobes, influenced by bed topography. The Des Moines lobe (DML), channeled by the Red River and Minnesota River valleys, advanced to a terminal position in central Iowa. Four dated ice margins provide chronological constraints for regional correlations: the Bemis at ~17.0 ka cal BP, the Altamont at ~16.2 ka cal BP, Algona at ~14.8 ka cal BP, and the Big Stone moraine at ~14.0 ka cal BP, which marks the transition to what is known as the Red River lobe. The number and timing of DML phases were reconstructed using multiple lines of evidence derived from geomorphic, lithologic, and stratigraphic analyses. In a study area located in southwestern Minnesota and eastern South Dakota, the delineation of subglacial bedforms was used to identify lateral shear margins positioned at the base of topographic highs. Locations of lateral shear margins also correlate to continuous glacial landforms and the greatest compositional variability within the till sheet, observed from modeling 451 DML till sample sites. Spatial relationships indicate that a single, heterogenous till sheet is surfically exposed throughout the study area and bed topography may have influenced ice-flow dynamics to generate faster flow. Correlations of moraines with the stratigraphy of Late-Wisconsinan sediments indicate there is one continuous basal till unit capped by discontinuous sorted, unsorted, and interbedded sediments that extends from the Bemis margin and continues up-ice of the Altamont moraine. A second till sheet overlies this stratigraphy north of the Algona moraine in Minnesota. Results suggest that the DML experienced two phases. The first, associated with the Bemis advance, is followed by a systematic retreat from the study area and reorganization of the ice mass. A second advance is associated with the Algona margin. The onset of global warming, defined by Greenland Interstade 1 (GI-1), occurred soon after the Algona advance at ~ 14.7 ka cal BP. Rapid climate change caused widespread stagnation and ice retreat to the Big Stone margin at a rate of 250 meters/year. The scale of stagnation and resulting surficial landforms is a unique response to unprecedented global warming associated with the GI-1 and probably not representative of earlier DML ice behavior. The ages of proglacial lakes that bound the Big Stone moraine suggest the margin is a recessional feature and does not represent a third advance.
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    A Land Suitability Study for Lakewood Township in St. Louis County, Minnesota
    (1977-05) Berner, Heinz
    The purpose of this paper is to provide opportunity for a practical exercise in regional planning. It must be emphasized that this paper is a report rather than an original planning contribution. Fieldwork other than four reconnaissance trips was not undertaken. Instead, data compilation has been achieved through personal consultation of local planning offices and governmental agencies as well as literature research. However, content and format (including graphical representation) are the result of the writer's work and judgement.
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    Macrofabric Analysis of Glacial Till
    (1971-12) Saremba, Scott P
    Previous studies on till fabrics of glacial tills indicate that the fabric elements are oriented in preferred directions. The long axes of elongated fabric elements are statistically oriented parallel or transverse to the directions of ice flow. Published studies on the mechanisms by which stones in till become oriented reveal that there is no one set mechanism by which a fabric element obtains a preferred orientation. A study of the till fabrics of the Twig, Independence, and Alborn quadrangles of northeastern Minnesota shows that the glacial tills usually have two preferred orientations, a major and minor orientation. The directions of the two preferred orientations of the till fabric are approximately at right angles to each other. In most cases the major preferred orientation is parallel to the direction of the known ice flow, but in some till fabrics the major preferred orientation is transverse to the direction of known ice movement. The long axes of elongated stones usually plunged up-glacier in the drumlin till, but there was no consistency to the pattern of plunge in the ground moraine till. It is advisable to limit as many variables of the till fabric element such as size, shape, and axial-ratio to obtain accurate results. The positive correlation obtained between the results of the author's till fabric analysis and Wright's and Watt's (1969) interpretation of the studied area support the use of preferred orientation of till fabric as a meaningful indicator of ice movement.
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    Municipal Solid Waste Disposal: A Problem in Environmental Geology
    (1977-06) Berner, Heinz
    This paper will discuss some of the aspects of municipal solid waste disposal, particularly the physical and technical problems associated with sanitary landfills. One of its purposes is to see to what extent geologic information can be helpful in solving specific land use problems such as the location of landfill sites. Furthermore, this report is primarily a library research paper, required for graduation.
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    Myth as True History: Medicine Wheels and Landmarks as Boundary Markers of the Lakota World
    (2016) Burley, Paul D
    This investigation examines physical, spatial and temporal characteristics of Native American medicine wheels located on the Northern Great Plains of the Unites States. Direct evidence for date and purpose of construction and use of medicine wheels is limited. As architectural symbols of native science, the structures are understood to be metaphors for native knowledge and creative participation with the natural world in both theory and practice, serving as bridges between the inner and outer realities. However, reasons for the respective location, meaning of architectural design, date of construction, and identification of people who constructed each medicine wheel generally remain unknown. An exception is Cloud Peak medicine wheel located on the west flank of the high point of the Bighorn mountain range in Wyoming, and shown to have been constructed by the Lakota tribe no earlier than about 1700 AD. Documented Lakota migration onto the Great Plains beginning during the early 17th century was reviewed to trace the timeframe and areal extent of the tribe's occupation of the region. Major regional and local physiographic features of the 2 Northern Great Plains were identified as they relate to Lakota traditional ecological knowledge (TEK). The tribe's history and culture, including mythology, cosmology, were reviewed from ethnographic records and documents addressing tribal history and sacred lifeway. Field observations were made of medicine wheel sites and physiographic features on the Northern Great Plains and adjoining regions of known import to the Lakota and other tribes which occupied the region during late prehistory. Observations and measurements of Cloud Peak medicine wheel, the Jennings site in east central South Dakota and additional archaeological sites of significance on the Northern Great Plains, and proximal relationships between those sites and major topographic and hydrogeologic features of the region suggest these features share common spatial, cosmographic and mythological relationships with the spiritual center of the Lakota world at Bear Butte, South Dakota. Based on locations of Cloud Peak medicine wheel and the Jennings site, physiographic and ecological characteristics of those locations and two additional sites of archaeological significance, and ethnographic records of Oceti Sakowin and Lakota TEK it is concluded these features compose primary elements of an Earth-scale sacred hoop delineating the physical boundaries of the traditional Lakota world. This sacred hoop was conceived, designed and built to include most of the Northern Great Plains region and traditional territory of the Lakota in particular. The hoop is interpreted to have been constructed soon after Lakota occupation of the Northern Great Plains by the late 18th century.
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    A Possible Late Pleistocene Impact Crater in Central North America and Its Relation to the Younger Dryas Stadial
    (2020-08-04) Tovar Rodriguez, David
    The causes that started the Younger Dryas (YD) event remain hotly debated. Studies indicate that the drainage of Lake Agassiz into the North Atlantic Ocean and south through the Mississippi River caused a considerable change in oceanic thermal currents, thus producing a decrease in global temperature. Other studies indicate that perhaps the impact of an extraterrestrial body (asteroid fragment) could have impacted the Earth 12.9 ky BP ago, triggering a series of events that caused global temperature drop. The presence of high concentrations of iridium, charcoal, fullerenes, and molten glass, considered by-products of extraterrestrial impacts, have been reported in sediments of the same age; however, there is no impact structure identified so far. In this work, the Roseau structure's geomorphological features are analyzed in detail to determine if impacted layers with plastic deformation located between hard rocks and a thin layer of water might explain the particular shape of the studied structure. Geophysical data of the study area do not show gravimetric anomalies related to a possible impact structure. One hypothesis developed on this works is related to the structure's shape might be explained by atmospheric explosions dynamics due to the disintegration of material when it comes into contact with the atmosphere. Relationship between structure's diameter (D) and deformed strata thickness (h) as well as the relationship between the diameter of the projectile (d) and the depth of the water column (H ), which is considered in this study due to the geographical considerations of the area 12.9 ky ago and BP, are consistent with an extraterrestrial event. Other hypotheses, such as lake processes and glacial processes, are difficult to reconcile with the reported observations, so the impact hypothesis and its relationship with the formation of the Roseau structure are viable.
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    A Testing of the Prediction of Floating or Settling of Phenocrysts in a Magma by Mathematical Models
    (1974-06) Saremba, Scott P
    Previous work on densities of liquid silicate systems suggest that it is mathematically possible to determine whether phenocrysts in a magma should settle or float based on the density difference between the magma and phenocrysts. The density of most magmatic liquids can be ca1culated from the equation: dmelt = εiXiMi/ViM1, where Xi is the mole fraction of component I, vi its partial molar volume, and Mi its gram formula weight. Mathematically derived results of density difference compare favorably with 4 out of the 5 field observations made on lavas and sills of the North Shore Volcanic Group. The good correlation between the results of the author's mathematically derived results and the field observation support the use of the mathematical model as a meaningful indicator of floating or settling of phenocrysts in a crystallizing melt. The single inconsistency (1 out of 5) suggest that factors other than density difference such as viscosity, affects density, crystal shapes, and convection in magmatic melts may have an effect on the settling or floating of phenocrysts. [See item for proper illustration of mathematical formula]