Download or read book Shorter Contributions to the Geology of the Sioux Quartzite early Proterozoic Southwestern Minnesota written by and published by . This book was released on 1984 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Paleomagnetism of the Early Proterozoic Sioux Quartzite Southwestern Minnesota implications for Correlating Quartzites of the Baraboo Interval written by Val W. Chandler and published by . This book was released on 1993 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paleomagnetic studies were conducted on the Early Proterozoic Sioux Quartzite, one of the so-called "Baraboo interval" red-bed sequences of the Lake Superior region. A total of 158 samples were collected from 17 sites scattered across four basins (Cottonwood County, New Ulm, northern Pipestone, and southern Pipestone) in southwestern Minnesota. Alternating-field and thermal demagnetization studies indicate that the magnetization is dominantly single component, and that the magnetic carrier is hematite. Hematite occurs both as a diagenetic mineral whose long paragenetic history began shortly after deposition and as veinlets that formed during a strain event possibly related to regional tilting. The magnetization is tentatively interpreted to have occurred before regional tilting, although a definitive fold test is difficult because dips are low. Measured paleomagnetic directions at both site and basin levels show good clustering, and the average directions obtained from each of the four basins are not significantly different at the 95 percent confidence level. The good clustering at all levels of sampling indicates that the Sioux Quartzite was magnetized either within a short time interval or during a period of subdued apparent polar wander. The structurally corrected paleomagnetic directions from the four basins yield a combined paleopole location at 1 01 ° W. and 16° N. (k=65, alpha 95=11 °). Dated paleopoles for Early Proterozoic rocks in North America and age dates of rocks interpreted to underlie the Sioux Quartzite imply that its age is 1,700-1,650 Ma. This interval corresponds in part with the age of 1,800-1,630 Ma of the Central Plains orogen, which lies some 200-300 kilometers south of the Sioux Quartzite out- crop. Quartzite may reflect a tectonic pulse related to the Central Plains orogen. Preliminary paleomagnetic data on Baraboo-interval quartzites from Wisconsin indicate that the Sioux paleopole cannot be distinguished at the 95 percent confidence level from that of the Barren Quartzite, but that it differs from that of the Baraboo Quartzite, which on the basis of existing apparent polar wander data could be as much as 100 million years older. The paleomagnetic data support previously raised cautions that some Baraboo interval quartz arenites may have been deposited in separate basins at significantly different times.

Download or read book U S Geological Survey Bulletin written by and published by . This book was released on 1983 with total page 282 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 U S Geological Survey Bulletin written by E. Neal Hinrichs and published by . This book was released on 1983 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modal, chemical, and isotopic data for the granitic rocks of the Tuolumne Meadows quadrangle.

Download or read book Contributions to the Quaternary Geology of Southwestern Minnesota written by Carrie J. Patterson and published by . This book was released on 1997 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Prehistoric Hunter Gatherers of the High Plains and Rockies written by Marcel Kornfeld and published by Routledge. This book was released on 2016-06-16 with total page 1055 pages. Available in PDF, EPUB and Kindle. Book excerpt: George Frison’s Prehistoric Hunters of the High Plains has been the standard text on plains prehistory since its first publication in 1978, influencing generations of archaeologists. Now, a third edition of this classic work is available for scholars, students, and avocational archaeologists. Thorough and comprehensive, extensively illustrated, the book provides an introduction to the archaeology of the more than 13,000 year long history of the western Plains and the adjacent Rocky Mountains. Reflecting the boom in recent archaeological data, it reports on studies at a wide array of sites from deep prehistory to recent times examining the variability in the archeological record as well as in field, analytical, and interpretive methods. The 3rd edition brings the book up to date in a number of significant areas, as well as addressing several topics inadequately developed in previous editions.

Download or read book Archean and Proterozoic Geology of the Lake Superior Region U S A 1993 written by Geological Survey (U.S.) and published by . This book was released on 1996 with total page 134 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 Centennial Field Guide written by Geological Society of America and published by Boulder, Colo. : Geological Society of America. This book was released on 1986 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings and Abstracts for the Annual Institute on Lake Superior Geology written by and published by . This book was released on 1990 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Institute on Lake Superior Geology written by and published by . This book was released on 1998 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laurentia written by Steven J. Whitmeyer and published by Geological Society of America. This book was released on 2023-01-04 with total page 824 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This Memoir focuses on 7 'turning points' that had specific and lasting impacts on Laurentian evolution: The Neoarchean, characterized by cratonization; the Paleoproterozoic and the initial assembly of Laurentia; the Mesoproterozoic southern margin of Laurentia; the Midcontinent rift and the Grenville orogeny; (5) the Neoproterozoic breakup of Rodinia; the mid-Paleozoic phases of the Appalachian-Caledonian orogen; and the Jurassic-Paleogene assembly of the North American Cordillerar"--

Download or read book Publications of the Minnesota Geological Survey and Its Predecessor the Geological and Natural History Survey of Minnesota written by Lynn Swanson and published by . This book was released on 1985 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Precambrian written by John Calvin Reed (Jr.) and published by . This book was released on 1993 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt: