Browsing by Subject "midcontinent rift"

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    Guidebook 20. Field Trip Guidebook for the Geology and Ore Deposits of the Midcontinent Rift in the Lake Superior Region
    (Minnesota Geological Survey, 1995) Miller, James D., Jr.
    This guidebook has been prepared for the field conference and symposium on "The Petrology and Metallogeny of Volcanic and Intrusive Rocks of the Midcontinent Rift System" that will be held in Duluth, Minnesota in August of 1995 as part of International Geological Correlation Program (IGCP) Project 336 ("Petrology and Metallogeny of Mafic and Ultramafic Magmatism"). The four-year-Iong IGCP project was begun in 1992 to investigate the petrology and metallogeny of various intracontinental mafic igneous provinces with an overall goal of establishing geological criteria for targeting mineral deposits in such environments. The principal goal of the 1995 meeting is to showcase to the international scientific and exploration communities the significant advances in our understanding of the structure, mineralization, and magmatic history of the Midcontinent rift. Toward this end, three field trips have been organized around the three-day symposium to be held August 25-27, 1995 in Duluth. The field trips are designed to provide a broad overview of the geologic framework of the Midcontinent rift, where it is best exposed in the western Lake Superior region. Field trip I (August 19 -24) looks at the physical volcanology of the flood basalts exposed on Isle Royale. Field trip II (August 22-24) highlights the stratigraphy, structure and mineralization of the volcanic and sedimentary rocks forming the southern limb of the Midcontinent rift in Wisconsin and Upper Michigan. The post-symposium field trip ill (August 28-September 1) focusses on the geology and ore deposits associated with the intrusive rocks of the Midcontinent rift exposed along the north shore of Lake Superior in Minnesota and Ontario.
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    Information Circular 47. Compositions of Rift-Related Volcanic Rocks of the Keweenawan Supergroup Atop the St. Croix Horst, Southeastern Minnesota
    (Minnesota Geological Survey, 2001) Morey, G.B.
    This information circular summarizes stratigraphic and geochemical information obtained in the 1980s and early 1990s from Mesoproterozoic volcanic rocks associated with the Midcontinent rift system. These rift-related rocks comprise the St. Croix horst, a major structural feature now mostly buried by a thin cover of generally flat-lying sedimentary rocks of Paleozoic age. Although the studies described herein were completed 10 to 15 years ago, the results have never been published. This report is intended to correct that omission.
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    OFR11-03, Compilation of Minnesota and Western Wisconsin Geoscience for the USGS National Geologic Carbon Dioxide Sequestration Assessment: Enhanced Geophysical Model for Extent and Thickness of Deep Sedimentary Rocks
    (Minnesota Geological Survey, 2011) Chandler, V.W.; Lively, R.S.
    In 2010, the Minnesota Geological Survey (MGS) was commissioned by the U.S. Geological Survey (USGS) to clarify available knowledge on the rocks that are most prospective for subsurface carbon dioxide sequestration in Minnesota and western Wisconsin. Although the prospective rocks, late Precambrian sedimentary basins of the Midcontinent Rift system (MRS), are at depths greater than the 1 km depth required for efficient carbon dioxide storage, and there is some potential for adequate porosity, permeability, and seals, the overall prospects for reservoir suitability are not promising from several perspectives. Nevertheless, the current USGS National Geologic Carbon Dioxide Sequestration Assessment project is presently seeking to clarify potential sequestration sites across the US. In response to a request from the USGS under this program, therefore, a summary of knowledge was assembled and enhanced, to provide the best readily available information on inferred geological tops, cross-sections, maps, geological history, and likely composition of the potential reservoirs and seals.
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    Potential Capacity for Geologic Carbon Sequestration in the Midcontinent Rift System in Minnesota
    (Minnesota Geological Survey, 2008) Thorleifson, L.Harvey, editor
    Minnesota, with a population of about five million, is a significant source of greenhouse gas emissions, and a state that is vulnerable to climate change, such as the impact that increased frequency or severity of drought would have on agriculture, water supply, wildlife, and lake levels. Minnesota therefore has an interest in reducing our own vulnerability, while concurrently contributing to needed world-wide solutions. As has been stressed, for example, in documents prepared for and by the Minnesota Climate Change Advisory Group, emissions reductions can have multiple benefits, including conservation, cost efficiency, and air quality enhancement, while also directly contributing to mitigation of climate change. Anthropogenic climate change seems already to have begun, however, so adaptation to climate change accompanies mitigation in the climate change policy agenda. Mitigation of greenhouse gas emissions can be achieved through reduced fossil fuel combustion, while concurrently capturing and storing carbon in biomass, or in geologic repositories. It has become apparent that the best approach in the current circumstances is for all options to concurrently be assessed.