Download or read book For Love of a River written by Darby Nelson and published by Beaver's Pond Press. This book was released on 2019-09-24 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growing up in the river town of Morton, Darby Nelson developed a deep taproot of affection that anchored his contagious curiosity about the land and people of the Minnesota River Valley. Now, with an ecologist's lens and a lifelong appreciation for wild and scenic places, Darby sets out with his wife, Geri, to paddle the river all the way from its source near the Minnesota-South Dakota border to its confluence with the Mississippi in the Twin Cities.
Download or read book U S Geological Survey Professional Paper written by and published by . This book was released on 1984 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Great Lakes Tectonic Zone revisited written by Paul Kibler Sime and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Great Lakes tectonic zone (GLTZ) is a Late Archean crustal boundary (paleosuture) at least 1,200 kilometers long that juxtaposes a Late Archean greenstone-granite terrane (Wawa subprovince of Superior province) on the north and an Early to Late Archean gneiss terrane (Minnesota River Valley subprovince) on the south. Recent mapping of an exposed seg- ment in the Marquette, Michigan, area provides new data on the vergence of the structure. These data necessitate reexami- nation of the COCORP seismic-reflection profiling in central Minnesota, which has been the principal basis for past views on the vergence of the GLTZ. In the Marquette area, the GLTZ is a northwest-striking mylonite zone about 2.3 kilometers wide that is superposed on previously deformed rocks of both Archean terranes. Shear zone walls strike N. 55°-60° W., and foliation in mylonite within the GLTZ strikes (average) N. 70° W. and dips 75° SW. A stretching lineation plunges 42° in a S. 43° E. direction. Hinges of tight to open (sheath?) folds of both Z- and S-symmetries plunge parallel to the lineation. The attitude of the lineation (line of tectonic transport and X finite strain axis), together with asymmetric kinematic indicators, indicates that collision at this locality was oblique; the collision resulted in dextral- thrust shear along the boundary, northwestward vergence, and overriding of the greenstone-granite terrane by the gneiss terrane. In contrast, the seismic-reflection profiling in central Minnesota has been interpreted by several investigators to indicate that the GLTZ is a shallowly north dipping (=30°) structure, which implies southward vergence on a north-dipping subduction zone. We suggest, alternatively, that the shallow- dipping reflectors in the seismic profiles indicate lithologic contacts related to recumbent and gently inclined folds (D1), perhaps enhanced by ductile deformation zones, and that the Morris fault is indeed the GLTZ. The Morris fault strikes about N. 70° E., dips steeply southeastward, is transparent in seismic profiles, appears to be narrow, and coincides with the inferred position of the GLTZ as shown on earlier maps. The oblique collision along northwest-trending segments of the GLTZ would be expected to produce dextral transpression across a large region north of the GLTZ, and may have produced an early nappe-forming event (D1) as well as younger upright folds (D2), and as a later, more brittle event, the numerous dextral faults and conjugate sinistral faults that are widespread in the Wawa and adjacent subprovinces.
Download or read book Reflection Seismology the Continental Crust written by Muawia Barazangi and published by . This book was released on 1986 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adventures Through Deep Time written by R. B. VanArsdale and published by Geological Society of America. This book was released on 2009 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the geologic history of the central Mississippi River Valley and the surrounding area from the Precambrian through the Holocene. Its focal point is the New Madrid seismic zone.
Download or read book The Deep Proterozoic Crust in the North Atlantic Provinces written by Alex C. Tobi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 601 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Proterozoic terrains of South Scandinavia and the Grenville Province in North-America have many common features : Regional high grade metamorphism (Granulite-facies), anorthosites, etc. They are separated by the Caledonian orogeny and, above all, by the Atlantic Ocean. During the time of the great continental drift controversy, few people were ready to admit that both sides on the Atlantic were once an unique province. Now everybody agrees on the Post-paleozoic age of the Atlantic and, consequently, on the intrinsic homogeneity of the much older. rocks which occur around it. But a detailed comparison is not easy. The Grenville Province is much larger than South Scandinavia, both regions have been investigated by a great number of different schools, using various methods, approaches and concepts. After several attempts, and long discussion, it was felt by a small group of individuals, that literature study would not be enough and that nothing could re place the direct contact, in the field, of specialists who had a first hand knowledge of all involved regions. The formula of a NATO Advanced Study Institute, which gives a unique opportunity to meet and mix people of various origin and levels, came almost by itself. Much work was needed, much help has been obtained, as detailed in the "Acknowledgements".
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 Mississippi Solo written by Eddy Harris and published by Macmillan. This book was released on 1998-09-15 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: The true story of a young black man's quest: to canoe the length of the Mississippi River from Minnesota to New Orleans.
Download or read book Cumulative List of Organizations Described in Section 170 c of the Internal Revenue Code of 1954 written by United States. Internal Revenue Service and published by . This book was released on 1976 with total page 1070 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Great Lakes Tectonic Zone in Marquette Area Michigan written by Paul Kibler Sims and published by . This book was released on 1991 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Geological Survey Bulletin written by Gene L. LaBerge and published by . This book was released on 1991 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reconnaissance study carried out in conjunction with regional geologic mapping.
Download or read book Geography and Geology of Minnesota written by Christopher Webber Hall and published by . This book was released on 1903 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contributions to Mineral Resources Research 1984 written by Alfred Lerner Bush and published by . This book was released on 1987 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Patterns of Change in Earth Evolution written by H.D. Holland and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: 3 of the experience of the last few generations. The group of happily unexperienced events includes large bolide impacts with the Earth. The evidence for the occurrence of such impacts at intervals of some tens of millions of years is quite convincing, and Lyell stands admonished by Hamlet: "There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy. " The role of bolide impacts on the history of life during other portions of the Phanerozoic Eon is less clear (see Raup and Fischer, both this volume), and catastrophic changes unrelated to extraterrestrial processes may have been important (see Holser, this volume). Changes in the later Precambrian biota are still difficult to interpret, in part because the preservation of soft-bodied animals from this period of Earth history is so unusual (see Seilacher, this volume). During the past billion years or so, bolide impacts have exerted a significant effect on the Earth's surface and its inhabitants, but not on its interior. The 3800 Ma rocks at Isua in West Greenland are the oldest terrestrial rocks that are currently available for inspection (see Dymek, this volume). They contain abundant evidence for the operation of chemical and physical processes that are similar to those of the present day. This situation could not have prevailed during the entire 700 Ma preceding the formation of the Isua rocks.
Download or read book History of Brown County Minnesota written by Louis Albert Fritsche and published by . This book was released on 1916 with total page 1144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
