Browsing by Author "Alexander Jr., E Calvin"
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Item 2017 York Blind Valley Dye Trace Fillmore County, MN(2018-10) Larsen, Martin R; Green, Jeffrey A; Barry, John D; Kasahara, Sophie M; Wheeler, Betty J; Alexander Jr., E CalvinItem August 1981 Root River Dye Trace(1981) Alexander Jr., E CalvinItem August 1982 Root River Dye Trace(Journal of Freshwater, 1982) Alexander Jr., E CalvinItem Electronic Access to Minnesota Springs, Karst Features and Groundwater Tracing Information(2018-04) Green, Jeffrey A; Tipping, Robert G; Barry, John D; Brick, Gregory A; Wheeler, Betty J; Rutelonis, J Wes; Richardson, Bart C; Alexander Jr., E CalvinItem Fountain Spring Cave Dye Trace Fillmore County, MN 2016 Dye Trace Report(2018-10) Larsen, Martin R; Barry, John D; Kasahara, Sophie M; Wheeler, Betty J; Alexander Jr., E CalvinItem Groundwater: Hidden Questions, Hidden Answers(Journal of Freshwater, 1983) Alexander Jr., E CalvinItem Harmony West Fillmore County, Minnesota 2018 Dye Trace Report(2018-09) Barry, John D; Green, Jeffrey A; Fischer, Caleb; Mathison, Aaren; Weiss, Jeffrey; Alexander Jr., E CalvinItem International Trace Olmsted County, Minnesota 2016 Dye Trace Report(2018-10) Barry, John D; Larsen, Martin R; Green, Jeffrey A; Rutelonis, J Wes; Alexander Jr., E CalvinItem Orion Sinkhole Plain - Devil’s Den Spring Complex; Olmsted County, Minnesota; 2018 Dye Trace Report(2020-01) Barry, John D; Green, Jeffrey A; Larsen, Martin R; Alexander Jr., E CalvinItem Sinkhole Distribution in Winona County, Minnesota(Proceedings of the First Multidisciplinary Conference on Sinkholes. Orlando, Florida 15-17 October 1984. "Sinkholes: Their Geology, Engineering and Environmental Impact. Edited by Barry F. Beck of the Florida Sinkhole Research Institute, University of Central Florida, Orlando. Page 311 - 318. Taylor & Francis, London, UK. Offprint., 1984-10-17) Dalgleish, Janet B; Alexander Jr., E CalvinWinona County, located in southeastern Minnesota, is part of a karst region in the upper Mississippi Valley. The karst is developing in flat-lying dolomitic Ordovician rocks. As part of a Minnesota Geological Survey county atlas program, we have systematically field located sinkholes, and prepared a 1 to 100,000 scale map showing sinkhole locations and sinkhole probability. We located 535 sinkholes in Winona County (~1600 [sq-km]). Most of these relatively small, geomorphically young sinkholes are not included in the USGS 7.5 minute topographic maps and cannot be readily detected on air photos. The sinkhole density, while low compared to many karst regions was much greater than local, regional, and state land use planners anticipated. New bedrock, surficial and hydrogeology maps of Winona County were used for correlation with the geographic distribution of the sinkholes. The primary control on the distribution of sinkholes appears to be the bedrock stratigraphy. The secondary controls, not necessarily in order of importance include slope of the land surface, and composition of surficial materials. The depth to the water table does not appear to have an important [effect] on sinkhole development. Age data indicate that the rate of sinkhole formation has [significantly] increased in recent years.Item Sinkhole Distribution in Winona County, Minnesota revisted(Proceedings of the Fifth Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst Gatlinburg/Tennessee/2-5 April 1995. Karst Geohazards Engineering and Environmental Problems in Karst Terrane. Edited by Barry F. Beck P. E. LaMoreaux & Associates, Inc., Oak Ridge, Tennessee (Formerly: Director of the Florida Sinkhole Research Institute). Assisted by Felicity M. Pearson. Page 265 - 272. Taylor & Francis, London, UK. Offprint., 1995-04-05) Magdalene, Suzanne; Alexander Jr., E CalvinThe sinkhole distribution in Winona County, Minnesota was first mapped by [Dalgleish] and Alexander (1984). They used the distribution of 535 sinkholes to define sinkhole probability zones. In 1992, a new survey identified an additional 73 sinkholes -- 39 older sinkholes missed in the first survey and 34 new sinkholes that have developed since 1983. All 73 sinkholes are located in the two highest sinkhole probability zones, supporting the criteria by which the original zones were delineated. The mean density of the Winona County sinkholes is 0.52 sinkholes/[sq-km] in the area underlain by the Prairie du Chien. Sinkholes only occur over the Prairie du Chien Group. A moving window analysis, using a 1.69 [sq-km] window and a 0.1 km step, was applied to determine the spatial distribution of sinkhole densities. The resulting sinkhole densities were contoured and range from 0 to 14.8 sinkholes/[sq-km]. A nearest-neighbor analysis was applied to the sinkhole data set. The observed mean distance between nearest-neighbors is 385 m. The range of nearest neighbor distances is 6m to 3999m. Test statistics by Skellam (1952) and Clark and Evans (1954) were used to test the nearest-neighbor distances against the values expected from a spatially random data set. Random data sets were created and analyzed for comparison. The observed sinkhole locations are significantly different than a random distribution in visual spatial distribution, in nearest-neighbor distance histograms, and in tests for randomness. With near certainty, the observed sinkholes are clustered. The observed mean nearest-neighbor distance is about half the distance expected for a random population with the same number of sinkholes. The 34 new sinkholes often develop in clusters and their [nearest-neighbors] are usually another new sinkhole. The observed directions to [nearest-neighbor] do not have preferred orientations along regional joint sets and are similar to the direction distribution calculated from random data sets. Sinkhole genesis does not appear to be structurally controlled in Winona County. Bedrock lithology, surficial geology, and topography of the land surface appear to be significant controlling factors.Item Springdale Dye Trace Report Olmsted County, Minnesota 2017 Dye Trace Report(2018-10) Barry, John D; Overbo, Alycia K; Green, Jeffrey A; Larsen, Martin R; Alexander, Scott C; Alexander Jr., E Calvin