Download or read book The Geology of the Middle Precambrian Rove Formation written by G. B. Morey and published by . This book was released on 1969 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Geological Survey Bulletin written by Paul Kibler Sims and published by . This book was released on 1983 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Early Proterozoic Michigamme Formation of northern Michigan was deposited in the southeastern part of the Animikie basin. The formation conformably overlies the Goodrich Quartzite and comprises three widespread members a lower member of thin-bedded shale, siltstone, and sandstone; the Bijiki Iron-formation Member; and an upper member of tur- biditic graywacke, siltstone, and mudstone and a few local members. The Goodrich Quartzite is interpreted as having been deposited in a tidally influenced shallow marine environ- ment. The lower member of the Michigamme is interpreted as having been deposited in a tidally influenced environment, the iron-formation member as having been deposited below wave base in somewhat deeper water, and the upper member as having been deposited in still deeper water with turbidity currents being a major depositional mechanism. Several lines of evidence including paleocurrents, paleo- geographic setting, and neodymium isotopes suggest that the graywacke of the southern part of the outcrop area was derived from the south (Early Proterozoic Wisconsin magmatic terranes, Archean miniplates, and older Early Proterozoic sedimentary units formed on the continental margin), and that the graywacke in the northern area was derived from an Archean terrane to the north. The tectonic model that best fits the available data is a northward-migrating foreland basin.
Download or read book U S Geological Survey Bulletin written by and published by . This book was released on 1983 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sedimentology and Provenance of the Early Proterozoic Michigamme Formation and Goodrich Quartzite Northern Michigan written by Richard W. Ojakangas and published by . This book was released on 1994 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Early Proterozoic Michigamme Formation of northern Michigan was deposited in the southeastern part of the Animikie basin. The formation conformably overlies the Goodrich Quartzite and comprises three widespread members a lower member of thin-bedded shale, siltstone, and sandstone; the Bijiki Iron-formation Member; and an upper member of tur- biditic graywacke, siltstone, and mudstone and a few local members. The Goodrich Quartzite is interpreted as having been deposited in a tidally influenced shallow marine environ- ment. The lower member of the Michigamme is interpreted as having been deposited in a tidally influenced environment, the iron-formation member as having been deposited below wave base in somewhat deeper water, and the upper member as having been deposited in still deeper water with turbidity currents being a major depositional mechanism. Several lines of evidence including paleocurrents, paleo- geographic setting, and neodymium isotopes suggest that the graywacke of the southern part of the outcrop area was derived from the south (Early Proterozoic Wisconsin magmatic terranes, Archean miniplates, and older Early Proterozoic sedimentary units formed on the continental margin), and that the graywacke in the northern area was derived from an Archean terrane to the north. The tectonic model that best fits the available data is a northward-migrating foreland basin.
Download or read book Ecology and Geology of the Superior Upland Region written by and published by . This book was released on 1982 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Iron Formation Facts and Problems written by A.F. Trendall and published by Elsevier. This book was released on 2000-04-01 with total page 559 pages. Available in PDF, EPUB and Kindle. Book excerpt: Iron-Formation: Facts and Problems
Download or read book Abstracts of North American Geology written by and published by . This book was released on 1971 with total page 1128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies in Mineralogy and Precambrian Geology written by Bruce R. Doe and published by Geological Society of America. This book was released on 1972 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precambrian Crustal Blocks in Minnesota written by S. R. Hemming and published by . This book was released on 1995 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sm-Nd survey of Precambrian granitic and metasedimentary rocks collected from several geophysically defined blocks in central Minnesota confirms the presence of some fundamental geologic boundaries previously mapped on the basis of structure. The Malmo discontinuity an Early Proterozoic structure separates the Archean Minnesota River Valley ter- ranes from an Early Proterozoic (Penokean magmatic) terrane and the McGrath Gneiss dome of east-central Minnesota North of this boundary, the Penokean fold-and-thrust belt can be divided into fault-bounded terranes that were assembled during the Penokean orogeny. Each terrane within the study area has distinct crust formation ages.
Download or read book Geological Survey Bulletin written by and published by . This book was released on 1972 with total page 1492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book North Central Section of the Geological Society of America written by Donald L. Biggs and published by Geological Society of America. This book was released on 1987 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Minnesota s Geology written by Richard W. Ojakangas and published by U of Minnesota Press. This book was released on 1982 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Have you ever wondered how the Mississippi River was formed? Or why shark teeth have been found in the Iron Range of the Upper Midwest? Towering mountain ranges, explosive volcanoes, expansive glaciers, and long-extinct forms of both land and sea life were an important part of Minnesota's ancient history. Today the evidence of this remarkable heritage is revealed in the state's rocky outcroppings, stony soils, and thousands of lakes.
Download or read book Archean to Anthropocene written by James D. Miller and published by Geological Society of America. This book was released on 2011-01-01 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precambrian Conterminous U S written by John C. Reed, Jr. and published by Geological Society of America. This book was released on 1993 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: This wide-ranging discussion of Precambrian rocks includes contributions from a diverse array of authors actively engaged in investigations of various aspects of U.S. Precambrian geology. Summary discussions by the editors of the five major chapters place these contributions in a logical regional framework.
Download or read book Report of Investigations written by and published by . This book was released on 1960 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lake Superior Iron Resources written by Edward G. King and published by . This book was released on 1960 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
