Browsing by Author "Meyer, Gary N."
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Item C-35, Geologic Atlas of Meeker County, Minnesota [Part A](Minnesota Geological Survey, 2015) Meyer, Gary N.A County Geologic Atlas project is a study of a county's geology, and its mineral and ground-water resources. The information collected during the project is used to develop maps, data-base files, and reports. This same information is also produced as digital files for use with computers. The map information is formatted as geographic information system (GIS) files with associated data bases. The maps and reports are also reproduced as portable document files (PDFs) that can be opened on virtually any computer using the free Acrobat Reader from Adobe.com.Item C-44, Geologic Atlas of Isanti County, Minnesota(Minnesota Geological Survey, 2017) Chandler, V.W.; Bloomgren, Bruce A.; Pettus, Margeurite C.; Runkel, Anthony C.; Hougardy, Devin D.; Meyer, Gary N.; Hamilton, Jacqueline D.A County Geologic Atlas project is a study of a county's geology, and its mineral and ground-water resources. The information collected during the project is used to develop maps, data-base files, and reports. This same information is also produced as digital files for use with computers. The map information is formatted as geographic information system (GIS) files with associated data bases. The maps and reports are also reproduced as portable document files (PDFs) that can be opened on virtually any computer using the free Acrobat Reader from Adobe.com. Due to errors found when work was started for the Part B, hydrogeology part of the Atlas, new sand/till rasters and unit masks have been added to this site in 2022 (Revisions to sand model data 2022).Item Information Circular 20. Aggregate Resources Inventory, Twin Cities Metropolitan Area, Minnesota(Minnesota Geological Survey, 1984) Meyer, Gary N.; Jirsa, Mark A.Aggregate is derived from two major sources in the seven-county area. Surficial deposits of sand and gravel, or "natural" aggregate, are the primary source. These are deposits of rock detritus broken down and sorted by the actions of glacial ice and running water. A second and increasingly important source is carbonate (limestone and dolomite) bedrock, which is converted to aggregate by blasting and crushing. Because ongoing urban development both restricts access to sources of aggregate and requires more aggregate for construction, a report was published by the Metropolitan Council of the Twin Cities area as an aid for industrial and governmental planners dealing with the problems of aggregate supply and demand. The plates and Appendix A of that report summarized the data in this information circular.Item Information Circular 23. Scientific Core Drilling in Central Minnesota: Summary of Lithologic and Geochemical Results(Minnesota Geological Survey, 1986) Southwick, D.L.; Meyer, Gary N.; Mills, Sarah J.In 1980 the Minnesota Geological Survey (MGS) began a program of scientific test drilling for the purpose of acquiring a better understanding of the complex Precambrian bedrock of central Minnesota. The areas investigated in this project contain very few bedrock outcrops; the Precambrian rocks are thickly covered by unconsolidated surficial deposits of Quaternary age, and the only way they can be directly sampled and studied is by core drilling. This circular is an essentially uninterpreted summary of basic lithologic and chemical data derived from the scientific core drilling project.Item Information Circular 24. Scientific Core Drilling in North-Central Minnesota: Summary of 1986 Lithologic and Geochemical Results(Minnesota Geological Survey, 1987) Mills, Sarah J.; Southwick, D.L.; Meyer, Gary N.In 1986, the Minnesota Geological Survey (MGS) continued a program of scientific test drilling for the purpose of acquiring a better understanding of the Precambrian bedrock of Minnesota. The work was undertaken as part of Minnesota's contribution to CUSMAP projects of the U.S. Geological Survey (USGS) in the International Falls and Roseau 10 x 20 quadrangles. The acronym CUSMAP refers to Conterminous United States Mineral Appraisal Program, a cooperative undertaking of the USGS and state geological surveys that, in the case of Minnesota, involves federal funding of high-resolution aeromagnetic surveys and state funding of follow-up test drilling and limited geologic mapping. A secondary objective of the drilling program has been the acquisition of subsurface data on the stratigraphy, lithology, and thickness of the Quaternary surficial deposits which overlie the Precambrian bedrock. A reconnaissance map of the surficial deposits in the Roseau 10 x 20 quadrangle (1:250,000) will be published in 1988.Item Information Circular 45. Utility of Elemental Geochemical Data in Correlation and provenance Studies of Pleistocene Materials: A Case Study in Stearns county, Central Minnesota(Minnesota Geological Survey, 2000) Morey, G.B.; Lively, R.S.; Meyer, Gary N.Geochemical attributes, especially minor, trace, and rare-earth elements, are commonly used to characterize various kinds of sedimentary rocks and to elucidate their provenance. Similar techniques have been applied to glacial materials with varying degrees of success. In Minnesota, for example, Martin and others (1989, 1991) concluded that few if any geochemical elements were useful for correlating tills across large areas. In contrast, Gowan (1998), in a study of six till units from central Minnesota, concluded that geochemical attributes were useful in delineating stratigraphic units and their provenance. Results of a similar study in southwestern Minnesota (Patterson and others, 1995) were inconclusive. The geochemical studies undertaken to date in Minnesota have utilized the silt and clay-size fraction as a sample medium and Atomic Adsorption spectrometry or Inductively Coupled Plasma emission spectrometry as the principal analytical technique. Unfortunately, both techniques require that the sample medium be dissolved prior to analysis, which can limit the value of the resulting data. For example, relative to the composition of the sample matrix and the particulates, certain minerals and elements may be selectively leached or incompletely dissolved, or spectral signals from some concentrated elements may interfere with weaker signals from less abundant elements. Such problems are best addressed by the use of replicates and standards developed from materials similar to those being analyzed. To our knowledge, sets of material standards that could be used to calibrate the various analytical methods have not been developed for Pleistocene sediments in Minnesota. In this study we avoided problems associated with partial dissolution and interference by using Instrumental Neutron Activation Analysis (INAA) techniques (XRAL Activation Services Inc., Ann Arbor, Michigan). We analyzed 123 subsurface samples from five drill sites in Stearns County, east-central Minnesota, for 32 elements. The results in this report are not directly comparable with those of Martin and others (1988), Gowan (1998), and Patterson and others (1995), because they were obtained on whole-rock samples from which only clasts of pebble or larger size had been removed. Nonetheless, the data provide insight into the utility of geochemical techniques to investigate provenance and transport patterns of glacial materials. The complete file of analytical data is summarized in the Appendix.Item RI-34 Subsurface Till Stratigraphy of the Todd County Area, Central Minnesota(Minnesota Geological Survey, 1986) Meyer, Gary N.Drilling logs, cuttings samples, and a limited amount of split-tube samples--acquired as a by-product of a crystalline basement drilling project-- provide evidence for informally naming nine new till units in central Minnesota. The Elmdale till may represent the first Pleistocene ice advance into central Minnesota. Other tills of northwestern provenance are the Eagle Bend, Meyer Lake, Green, and Browerville. Although shale is generally rare, these tills typically contain appreciable amounts of Cretaceous rock fragments, chiefly from the Greenhorn Limestone. The Second Red, First Red, Sandy, and Red Sandy are pre-Wisconsinan tills of northeastern provenance. They compose only a minor portion of the Pleistocene deposits in the Todd County area, but indicate alternate northeastern and northwestern ice advances. The surf icial Wadena till had a northeastern source, as indicated by lithology, texture, and drumlin orientation. Its relatively high carbonate content, which led earlier workers to ascribe a northwestern provenance, was deri ved through incorporation of older drif t. The Elmdale, Second Red, and Eagle Bend tills are thought to be pre-Illinoian; the First Red, Meyer Lake, and Green tills, pre-Illinoian or Illinoian; the Sandy and Browerville, Illinoian; and the Red Sandy, Illinoian or early Wisconsinan in age. A new radiocarbon date of 36,970 B.P. from a wood sample above the Wadena till supports an early Wisconsinan age designation for the surficial till over much of Todd County.Item RI-48 Pre-Late Wisconsinan Till Stratigraphy of North-Central Minnesota(Minnesota Geological Survey, 1997) Meyer, Gary N.Continuous cores of complete Quaternary sections at more than 60 sites in north-central Minnesota yield evidence for at least nine pre-late Wisconsinan tills. Found only in the subsurface, they are of both northwest and northeast provenance. The oldest till-the Mulligan Lake of northeast provenance-does not have a recognized counterpart to the south. Tills of northwest provenance-Wirt Lake, Bigfork, Eagle Bend, Funkley, and Browerville-are correlated with tills recognized earlier in central Minnesota. The younger northeastprovenance tills-Shooks, First Red, and Saum-also are correlated with till units recognized in central Minnesota. The subsurface record indicates alternating northeastern and northwestern advances during each major glaciation in north-central Minnesota. The distinct couplets of northeast- and northwest-source tills imply shifting locations for the Labrador and Keewatin ice centers during the Pleistocene. The Pleistocene stratigraphic sequence of Minnesota is divided into five informal "event" units based on the subsurface record. Evidence for the earliest of these--event V-is limited, but its tills are similar to tills of event X. During event W, ice carrying detritus of Rainy provenance extended from north-central Minnesota into central Minnesota. During this interval, ice carrying detritus of Winnipeg provenance moved south across and probably beyond Minnesota. During event X, ice carrying material of Superior provenance dominated flow from the Labrador center into north-central Minnesota at a time when ice carrying Rainy-provenance detritus apparently did not enter the state. Throughout event X, ice carrying Winnipeg-provenance detritus flowed southeastward into Minnesota, and probably again well south and east of the state. Event Y was marked by a resurgence into central Minnesota of ice carrying Rainy-provenance debris, with ice carrying Winnipeg-provenance debris again flowing into the state in a more southward direction. The final event Z comprises the late Wisconsinan glaciation when Keewatin ice expanded from a direction more to the west of Minnesota (incorporating material of Riding Mountain provenance) than earlier advances of ice carrying Winnipeg-provenance material. Sediments of event Y are probably illinoian or older, whereas those of events X, W, and V are probably pre-illinoian in age. The sedimentary record is evidence that the Keewatin and Labrador ice centers were both phenomena of the Laurentide ice sheet throughout the Pleistocene, although their locations probably shifted considerably through time.Item RI-68 Quaternary Lithostratigraphic Units of Minnesota(Minnesota Geological Survey, 2016-03) Johnson, Mark D.; Adams, Roberta S.; Gowan, Angela S.; Harris, Kenneth L.; Hobbs, Howard C.; Jennings, Carrie E.; Knaeble, Alan R.; Lusardi, Barbara A.; Meyer, Gary N.;Much of Minnesota is covered by sediment of Quaternary age that was deposited during numerous glaciations by ice, wind, and water. In this report, we follow guidelines of the North American Stratigraphic Code (North American Commission on Stratigraphic Nomenclature, 2005) to create a framework for establishing formal lithostratigraphic units in Minnesota. We evaluate over 100 lithostratigraphic units that have been identified in Minnesota. Eighty (80) units are considered to be useful lithostratigraphic units of formation and member rank, and these are formally accepted in this report or are recommended to be so in future publications. These 80 units include previously named formal lithostratigraphic units that are recognized and accepted as originally defined, but also formally defined units that we have revised or redefined to better fit into our stratigraphic framework. The remaining lithostratigraphic units have been used informally in earlier reports or are newly named in this report. Additional units that are no longer considered necessary as lithostratigraphic units are abandoned in this report. These units include previously used units of both formal and informal status. Of the 80 lithostratigraphic units recommended to be retained, 47 are formally defined, revised, or redefined in this report. The remaining 33 units are recommended to be formally named in a future Minnesota Geological Survey Report of Investigations.