Browsing by Subject "drilling"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Information Circular 11. The Basis for a Continental Drilling Program in Minnesota
    (Minnesota Geological Survey, 1976) Morey, G.B.
    The use of drill holes for the direct sampling and measurement of materials and properties beneath the earth's surface is the only really effective method of solving many basic scientific and practical problems. Although two to three million holes have been drilled in North America, they are concentrated in oil producing regions or in sedimentary rock. Comparatively few holes have been drilled in igneous and metamorphic rock, and many areas of scientific interest but less obvious economic importance have not been drilled at all. A select committee at a workshop on continental drilling held June 10-13, 1974 at Ghost Range, Abiquiu, New Mexico (Shoemaker, 1975) has proposed a 10-year program, aimed at the systematic exploration of the North American plate in much the same way that the Deep Sea Drilling Project has attacked the problems of the ocean basin. This program calls for the drilling of many shallow holes 30-300 m) and a few intermediate to deep holes (300-9,000 m). The impact of the results of deep sea drilling on geologic thought already has profound implications for future development of the earth's resources and should justify similar research on the continents.
  • Thumbnail Image
    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.
  • Thumbnail Image
    Item
    Information Circular 31. Scientific Test Drilling in West-Central Minnesota Summary of Lithologic and Stratigraphic Results, 1987-1988, and Some Preliminary Geological Conclusions
    (Minnesota Geological Survey, 1990) Southwick, D.L.; Setterholm, Dale R.; Boerboom, Terrence J.
    In 1980 the Minnesota Geological Survey (MGS) began a program of scientific test drilling designed to acquire a better understanding of the complex Precambrian bedrock of Minnesota. A research approach that combined selective test drilling with geophysical surveying of the Precambrian terrane was dictated by the fact that the Precambrian rocks are covered by substantial thicknesses of Quaternary glaciogenic sediment in most places and therefore are not amenable to standard mapping and sampling techniques. This circular is the fourth to report basic results from the drilling program. It contains data from four separate studies that were undertaken in central and western Minnesota in 1987-1988 (Fig. 1). The drilling summarized here, like that in previous projects (Southwick and others, 1986; Mills and others, 1987; Boerboom and others, 1989), was closely coordinated with geophysical surveys, and the selection of drilling targets was guided by geophysics to the maximum extent practicable. Our standard procedure was to formulate regional interpretations of the buried Precambrian geology from the geophysical data and then drill to verify, modify, or otherwise constrain the geophysical interpretation. Earlier applications of this approach have contributed to regional-scale geologic maps of the Penokean orogen (Early Proterozoic) in east-central Minnesota (Southwick and others, 1988) and an Archean greenstone belt in north-central Minnesota (Jirsa and Boerboom, 1990); the data tabulated in this circular will eventually contribute to new geologic maps for west-central Minnesota.
  • Thumbnail Image
    Item
    Information Circular 37. Scientific Core Drilling in Parts of Itasca, St. Louis, and Lake Counties, Northeastern Minnesota, 1989-1991
    (Minnesota Geological Survey, 1993) Meints, Joyce P.; Jirsa, Mark A.; Chandler, V.W.; Miller, James D., Jr.
    This information circular is the fifth since 1980 to report on the basic results of test drilling (Fig. 1) by the Minnesota Geological Survey (MGS). As with the previous projects, this test drilling was conducted primarily to provide a better understanding of the Precambrian geology in areas of Minnesota where bedrock is covered by variable thicknesses of glaciogenic sediment, and thus could not be thoroughly mapped by standard outcrop mapping and sampling procedures. The drilling summarized here was conducted during 1989-1991 in areas where the bedrock is locally well exposed, but where exposures are separated by covered terrane. Thus, the selection of drill targets was constrained largely by the interpretation of geophysical surveys (Chandler, 1983a, b). Our procedure is to formulate a regional geologic interpretation based on geophysical maps, new and existing outcrop data and the archived records of previous drilling, and then to constrain and test the interpretation by selective drilling. The results have been incorporated into new geologic maps of the region including Jirsa and others (1991) and Southwick (in prep.). An important secondary objective of this project is to describe the Quaternary deposits that overlie bedrock, though no systematic regional interpretation of those deposits has been undertaken to date. This report summarizes the results of studies in two areas of vastly different geology: 1) Archean and Early Proterozoic rocks of the Cook area in west-central St. Louis and eastern Itasca Counties, and 2) Middle Proterozoic rocks of the central Duluth Complex in parts of St. Louis and Lake Counties. The geology of each area is summarized in the "results" section of this report.
  • Thumbnail Image
    Item
    Information Circular 39. Scientific Test Drilling, 1989-1992: Descriptions and Interpretations Pertinent to the Bedrock Geology and Quaternary Hydrogeology of Southwestern Minnesota
    (Minnesota Geological Survey, 1993) Southwick, D.L.; Setterholm, Dale R.; Runkel, Anthony J.; Patterson, Carrie J.; Chandler, V.W.
    In 1980 the Minnesota Geological Survey (MGS) started a program of scientific test drilling designed to acquire a better understanding of the complex Precambrian bedrock of Minnesota. A research approach that combined selective test drilling with geophysical surveying of the Precambrian terrane was dictated by the fact that the Precambrian rocks are covered by substantial thicknesses of quaternary glaciogenic sediment in most places and therefore are not amenable to standard outcrop mapping techniques. This circular is the seventh to report basic results from the drilling program. It contains data from 20 holes drilled for three separate studies undertaken in southwestern Minnesota in 1989-92. The drilling for two of the three projects reported here was closely coordinated with geophysical surveys, and the selection of drilling targets was guided by geophysics to the maximum extent practicable. The third study, consisting of the single hole PR-90-1, was somewhat abnormal in that drilling was targeted on a topographic rather than a geophysical feature (see discussion below for details). Apart from this one exception, our standard procedure was to formulate regional interpretations of the buried Precambrian geology from the geophysical data and then drill to verify, modify, or otherwise constrain the geophysical interpretation. Earlier applications of this approach have contributed to regional-scale geologic maps of the Penokean orogen (Early Proterozoic) in east-central Minnesota (Southwick and others, 1988) and an Archean greenstone belt in north-central Minnesota (Jirsa and Boerboom, 1990; Jirsa, 1990; Jirsa and others, 1991). The data tabulated in this circular will eventually contribute to a new geologic map for southwestern Minnesota.
  • Thumbnail Image
    Item
    Information Circular 40. Scientific and Exploration Drilling in Northwestern Minnesota
    (Minnesota Geological Survey, 1993) Jirsa, Mark A.; Boerboom, Terrence J.
    Scientific test drilling in northwestern Minnesota was undertaken by the Minnesota Geological Survey (MGS) primarily to elucidate the geology of Precambrian and Phanerozoic bedrock in this area where the bedrock is buried beneath several hundred feet of Quaternary glacial sediment. The results of this drilling of 23 holes, and of selected logging, and analyses of the approximately 80 archived records and core from previous drilling, are presented in this report. These data, in conjunction with various geophysical maps, were utilized by the authors and others to construct a series of new geologic maps of northwestern Minnesota that are part of MGS Open-File Report 93- lA (Jirsa and others, 1993). Parts of that report will soon be published in the MGS Miscellaneous Map Series. An important secondary objective of this project is to describe the Quaternary deposits that overlie bedrock, though no systematic regional interpretation of those deposits has been undertaken to date. This is the seventh information circular since 1980 to report the results of test drilling by the Minnesota Geological Survey. Figure 1 shows the areas covered by those earlier studies in relation to this study area in northwestern Minnesota.
  • Thumbnail Image
    Item
    Information Circular 42. Scientific Test Drilling and Mapping in East-Central Minnesota, 1994-1995: Summary of Lithologic Results
    (Minnesota Geological Survey, 1997) Jirsa, Mark A.; Chandler, V.W.
    This report summarizes the results of test drilling, outcrop mapping, and geophysical analyses conducted by the Minnesota Geological Survey (MGS) in east-central Minnesota (Fig. 1). It is a companion to MGS Open-File Report 95-1 Jirsa, and others, 1995a). The results reported here, along with information from water-well records; exploration, engineering, and scientific test drilling; and existing geophysical maps, were used to construct the open-file map and the geological description in the following section. The western part of the map relies heavily on the interpretations of Boerboom and others (1995). Because geophysical data and interpretations played an essential role in targeting drill-hole locations and creating the geologic map, they are presented in a separate publication (Chandler and Jirsa, in preparation). This study focused on the Archean and Early Proterozoic geology of east-central Minnesota, which was some of the least understood in Minnesota. Previous interpretations depicted the area as largely Penokean granitoid intrusions. This work indicates that much of the area is indeed granitic; however, gravity and aeromagnetic data, and results given here, provide new insight about diverse rock types and complex structures that are also present. In addition, the study provided valuable stratigraphic information about the Middle Proterozoic (Keweenawan), Paleozoic, and Cretaceous bedrock, Quaternary glacial sediments, and the nature of boundaries between these strata.