Browsing by Author "Stauffer, Clinton R."
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Item Bulletin No. 23. The Limestones and Marls of Minnesota(Minnesota Geological Survey, 1933) Stauffer, Clinton R.; Thiel, George A.Minnesota has extensive deposits of calcium carbonate in the form of limestones, dolomites, and marls. This report deals primarily with the distribution and chemical composition of these carbonate deposits and the uses for which they are suited. The dolomites are the most widely distributed and the most readily available carbonate rocks in Minnesota. They are quarried in large quantities in the southeastern part of the state, where the lower Ordovician rocks are predominantly dolomitic limestones. Limestones high in calcium are far less abundant, being confined to several strata that are more limited in their distribution. Locally they have been quarried for their high lime content. The marls have been but very recently recognized as one of the valuable mineral resources of the state. These light, grayish muds underlie marshes, bogs, and lakes; they are not often visible at the surface. Most persons, therefore, are unfamiliar with the name, appearance, and distribution of marl. It can be distinguished from other muds by its light color, its abundant shell fragments, and its violent reaction with acid. The marl beds of Minnesota vary in thickness, but they are seldom more than thirty feet thick.Item Bulletin No. 29. The Paleozoic and Related Rocks of Southeastern Minnnesota(Minnesota Geological Survey, 1941) Stauffer, Clinton R.; Thiel, George A.The area covered by this report is mainly the southeastern part of Minnesota. It includes that portion of the state lying along or bounded by the St. Croix, the Minnesota, and the Mississippi rivers from Pine County southward to the Iowa state line and from Brown County eastward to the Wisconsin state line. Adjoining areas are referred to at various points in the text, chiefly for correlative purposes or in order to clarify the discussion. This area lies mostly within the hardwood timber section. Numerous towns and villages dot the region, which is part of the more thickly populated area of Minnesota, settled for over seventy-five years and first pioneered over one hundred years ago. Many of the old traders and missionaries traveled its navigable waters early in the seventeenth century; and for untold centuries before that it was an important part of the great hunting ground of the American Indian. The state of Minnesota lies on the southern border of the great Canadian Shield, so that much of its surface is covered by the preCambrian rocks characteristic of that ancient land mass. There more recent sediments overlie these older rocks, they vary in age from Cambrian to Cretaceous and later, for the glacial drift and the recent non-marine sediments may lie directly on the preCambrian. The strand line of Paleozoic and late Mesozoic time often passed through Minnesota; and the position of the ancient shore, varying from time to time, left many unconformities. The significance of some of these unconformities may not yet be fully appreciated, but they range from short breaks (diastems) in sedimentation, like those in the St. Croixian series, to great erosion intervals (disconformities) like that between the Maquoketa formation and the Cedar Valley limestone, where a whole system and fully half of another are wanting. It is evident, therefore, that during these long intervals diastrophism caused the land mass to the north to be extended beyond the boundaries of the state and that during such periods profound erosion must have affected this area, removing an unknown amount of the surface, probably base-leveling it several times.Item The High Calcium Limestones of Minnesota(Minnesota Geological Survey, 1947) Thiel, George A.; Stauffer, Clinton R.Item The High Magnesium Dolomites and Dolomitic Limestones of Minnesota(Minnesota Geological Survey, 1950) Stauffer, Clinton R.Item The Iron Ores of Southeastern Minnesota(Minnesota Geological Survey, 1949) Stauffer, Clinton R.; Thiel, George A.