Browsing by Author "Beltrame, R.J."
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Item Field mapping in the Duluth Complex; Gabbro Lake quadrangle, Northern Minnesota(Minnesota Geological Survey, 1974) Beltrame, R.J.Item Information Circular 12. Selected Bibliography of Cuyuna Range Geology, Mining and Metallurgy(Minnesota Geological Survey, 1977) Beltrame, R.J.This work is an extension of a bibliography prepared by the author as part of a final report submitted to the U.S. Bureau of Mines for grant # G026/t002 entitled "Manganese-bearing ores of the Cuyuna iron range, east-central Minnesota, Phase 1". This bibliography, though directed primarily towards the geologic and mining literature of the Cuyuna range, does include the major works on the metallurgical aspects of the Cuyuna ores. For historical interest the very earliest publications are included. This list of abbreviations given on pages 2-4 are consistent with those from the "Bibliography and Index of Geology".Item Information Circular 13. Directory of Information on Cuyuna Range Geology and Mining(Minnesota Geological Survey, 1977) Beltrame, R.J.This directory is a revision of a portion of a final report prepared for the U.S. Bureau of Mines for grant #G0264002 entitled "Manganese-bearing ores of the Cuyuna iron range, east-central Minnesota, Phase 1". This work arose from the need for a compilation of basic geologic and mining information on the Cuyuna range. This work is intended to compliment the "Selected bibliography of Cuyuna range geology, mining and metallurgy", Minnesota Geological Survey, Inf. Circ. 12, and "Manganese resources of the Cuyuna range, east-central Minnesota: a preliminary appraisal", Minnesota Geological Survey, Rep. Invest. 18.Item Information Circular 14. Index to Geophysical Investigations in Minnesota(Minnesota Geological Survey, 1978) Beltrame, R.J.This report was prepared for the Conference on Geophysics in Minnesota, May 1-2, 1978, at the Radisson Hotel, St. Paul, Minnesota. The purpose of this conference is to discuss the future direction for applied geophysical investigations in the State of Minnesota. This report was prepared as a source of background information on the present status of geophysical studies in the State. A detailed search for information on all aspects of geophysical investigations in Minnesota was undertaken. This report is concerned primarily with geophysical studies involving one or more of the following methods: electrical; electromagnetic; gravity; magnetic; seismic; and radioactive. For the first five topics, an index map and a list of references to areas studied in the state are provided. An index map to Radioactive investigations was not compiled because the numerous small areas of investigations by several investigators make it unfeasible. Also included in this report are selected references to miscellaneous geophysical investigations of a general nature, paleomagnetic studies; and references to studies on the Midcontinent Gravity High of which geophysics has played an important role.Item Manganese-bearing ores of the Cuyuna Iron Range, east-central Minnesota, Phase 1(Minnesota Geological Survey, 1977) Morey, G.B.; Broberg, J.; Beltrame, R.J.; Holtzman, R.C.Item RI-24 Manganese Resources of the Cuyuna Range, East-Central Minnesota(Minnesota Geological Survey, 1981) Beltrame, R.J.; Holtzman, Richard C.; Wahl, Timothy E.The Cuyuna range, located in east-central Minnesota, consists of a sequence of argillite, siltstone, iron-formation, graywacke, slate, and quartzite of early Proterozoic age. Manganese-bearing materials occur within the iron-rich strata of the Trommald Formation and the Rabbit Lake Formation. Computer-assisted resource estimates, based on exploration drill hole information, indicate that the Cuyuna range contains a minimum of 176 million metric tons (MMT) of marginally economic manganiferous rock with an average grade of 10.46 weight percent manganese. The calculated 18.5 MMT of manganese on the Cuyuna range could supply this country's needs for this important and strategic metal for nearly 14 years. An additional resource of 6.9 MMT of manganese metal is available in the lower grade deposits. The vast majority of these calculated resources are extractable by current surface mining techniques.Item RI-27 Geophysical Investigation of the Cedar Mountain Complex, Redwood County, Minnesota(Minnesota Geological Survey, 1982) Beltrame, R.J.; Chandler, V.W.; Gulbranson, Brian L.The Cedar Mountain Complex is a roughly circular composite intrusion, 500 to 600 m in diameter, in the Archean gneiss terrane of southwestern Minnesota. Emplaced during early Proterozoic time, the complex consists of a central core of monzonite surrounded by slightly older, compositionally layered dioritic rocks. Existing geophysical and geologic data indicate that the complex may reflect a widespread igneous event that also formed the granite-rhyolite terrane of central Wisconsin. A gravity and magnetic survey was conducted over the Cedar Mountain Complex to (1) delineate the contacts which are nowhere exposed; (2) interpret the configuration of the intrusion at depth; and (3) determine what relationships the complex may have with similar intrusions in the area and determine how they might be detected geophysically. Magnetic anomaly and rock property data indicate that the dioritic rocks are the principal sources of anomalies and that they are polarized near or along the present earth's field. Magnetic anomaly data indicate an angular and irregular configuration for the diorite-gneiss contact and a somewhat rectangular configuration for the monzonite-diorite contact. Model studies of the magnetic data imply that some contacts may dip steeply outward, but most are nearly vertical. The gravity anomaly data indicate that the core monzonite may be in part underlain by dioritic rocks. The configuration of the outermost contact and the density constraints indicate forceful injection as the mechanism for emplacement of the dioritic rocks. Similar emplacement is possible for the core monzonite, but the regular configuration of the inner contact, density constraints, and gravity interpretation favor stoping out of large blocks of diorite. Upward continuation of the magnetic data indicates that gross anomaly attributes of the complex and related intrusions would be detectable by aeromagnetic surveying using a flight-line spacing of 400 m and terrain clearance of 150 m.Item Uranium resource evaluation, New Ulm quadrangle, Minnesota(Minnesota Geological Survey, 1980) Morey, G.B.; Southwick, D.L.; Lively, R.S.; Beltrame, R.J.Item Uranium resource evaluation, St. Cloud quadrangle, Minnesota(Minnesota Geological Survey, 1980) Morey, G.B.; Southwick, D.L.; Lively, R.S.; Beltrame, R.J.