Browsing by Author "Knaeble, A.R."

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    Guidebook 22. Field Trip Guidebook Landforms, Stratigraphy, and Lithologic Characteristics of Glacial Deposits in Central Minnesota
    (Minnesota Geological Survey, 2006) Knaeble, A.R.
    This guidebook was prepared for the 50th Midwest Friends of the Pleistocene Field Conference, sponsored by the Minnesota Geological Survey and held at St. John's University on June 4-6, 2004. The purpose of this guidebook is to provide conference participants with an up-to-date general summary of the glacial geology of central Minnesota and a comprehensive reference list of previous research completed in the area. There are a number of reasons why we were motivated to host the Friends of the Pleistocene in central Minnesota. First, over the last 10 years the Minnesota Geological Survey has completed numerous mapping projects in the central Minnesota area (Steams, Pope, and Crow Wing County atlases; the Otter Tail regional hydrogeological assessment; and the USGS Statemap St. Cloud, Baxter, Brainerd, and Gull Lake quadrangle maps), and is in the process of completing mapping projects in Todd, Traverse, and Grant Counties. The large volume of data (samples and descriptions from outcrops and drill holes) collected from these projects has allowed us to evaluate the work done by previous researchers and contribute new insights and interpretations. Second, in 1954 Herb Wright, AI Schneider, and Harold Ameman led the 5th Midwest Friends of the Pleistocene field trip in central Minnesota. We will revisit the area, on this 50th anniversary of that trip, to examine how interpretations have changed and evolved. The guidebook will use a simple, direct approach to summarize the region's glacial geology, similar to that used in 1954. It is our intention to pay tribute to the accomplishments of Herb and AI during the field trip and banquet. We will also acknowledge other researchers who, over the last 50 years, have made contributions to the glacial geology of central Minnesota. Third, we would like to discuss how mapping techniques and technology have changed in the last 50 years. We will examine which techniques have been most effective in understanding the complex stratigraphy of central Minnesota. Finally, field exposures were selected to stimulate interest and discussion about the following glacial topics: erosion, transport, and deposition of source-area materials; processes involved in drumlin formation; the relationship between ice dynamics and glacial landforms; processes important in the formation of the St. Croix moraine; and the challenges of interpreting thick, complex drift stratigraphy. These stops highlight geomorphic features, stratigraphic relationships, and specific unit characteristics (lithology, color, etc.) in an attempt to provide an overview of the glacial geology of this region.
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    M-115 Surficial geology of the St. Cloud 30 x 60 minute quadrangle, central Minnesota.
    (Minnesota Geological Survey, 2001) Meyer, G.N.; Knaeble, A.R.; Ellingson, J.B.
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    OFR 07-01, Till geochemical and indicator mineral reconnaissance of Minnesota
    (Minnesota Geological Survey, 2007) Thorleifson, L.Harvey; Harris, K.L.; Hobbs, H.C.; Jennings, C.E.; Knaeble, A.R.; Lively, R.S.; Lusardi, B.A.; Meyer, G.N.
    As a cooperative project of the Minnesota Geological Survey and industry, the entire State of Minnesota and adjacent regions was sampled for till geochemistry and indicator minerals at a 30-km spacing during summer 2004. Within target cells, each a quarter-degree latitude by a half-degree longitude, till from between about 1 and 2 m depth was sampled by filling a 15 liter plastic pail. At a few sites, vertical profiles were collected. In addition, three transects to the north were sampled, to help identify sediments derived by long-distance glacial transport, to obtain reference samples from the Thompson nickel belt, and also to extend sampling to the limit of Hudson Bay-derived carbonate-bearing sediments, to permit comparison to Minnesota carbonate-bearing sediments. Three control samples anomalous in kimberlite indicator minerals from Kirkland Lake, Ontario, were also obtained. The resulting batch consisted of 250 samples covering Minnesota and adjacent areas, 20 samples from Canada, and the three standards. The results are a highly significant step forward in mapping our geochemical landscape, in clarifying mineral potential, in provision of reference data useful to environmental protection, public health, and exploration, and in supporting follow-up with respect to potential mineralization.
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    OFR10-06, Cuttings Summary for the Minnesota Department of Natural Resources South-Central Drilling Program
    (Minnesota Geological Survey, 2010) Knaeble, A.R.; Meyer, G.N.; Mossler, J.H.
    This report summarizes the glacial and bedrock geology for 15 drill holes completed by the Minnesota Department of Natural Resources (DNR) during 2008 and 2009. Cuttings from each drill hole were collected at the drill site by DNR staff, processed in the Minnesota Geological Survey (MGS) soil lab, examined and interpreted by MGS staff, and archived in the MGS cuttings collection. Geophysical logging was completed at each site by the MGS. The geologic interpretations for both the glacial and bedrock cuttings should be considered preliminary. This is due to the fact that field work for the MGS south-central atlas project is still in progress (recently collected field samples and drill core are still being processed and interpreted). Findings from this data may require reevaluation of some interpretations made in this summary. The following notes are provided to assist in understanding the formation descriptions (listed stratigraphically from youngest to oldest) in the glacial portion of the summary.