Download or read book Thick skinned South verging Backthrusting in the Felch and Calumet Troughs Area of the Penokean Orogen Northern Michigan written by J. S. Klasner and published by . This book was released on 1993 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Felch and Calumet troughs area of northern Michigan is part of the Penokean fold-thrust belt of the continental foreland of the Superior craton. The area lies immediately north of the Niagara fault zone, the north-verging suture between the continental foreland and the Early Proterozoic Wisconsin magmatic terranes to the south. Accretion of the magmatic terranes to the continental margin approximately equals 1,850 Ma produced south-verging backthrusting and backfolding in this region involving both Archean basement and Early Proterozoic supracrustal strata. Evidence for backthrusting exists throughoutthe Felch and Calumet troughs area. The backthrusting is characterized by southward-overturned bedding and small-scale, south-verging asymmetric folds with a subhorizontal axial-planar foliation. The Carney Lake Archean block appears to be a crystalline-core nappe wherein the Sturgeon Quartzite of the Chocolay Group forms the lower overturned limb. The deformation probably started as a north-verging foreland thrust event, but out-of- sequence south-verging backthrusts and backfolds developed to accommodate abrupt changes in crustal thickness along the continental margin. The backthrusting in the Penokean orogen resembles that in the younger rocks of the southern Alps. Proceeding inward from the continental margin, both orogens have accreted oceanic crust, indicated by the presence of ophiolite, that is thrust onto the continental margin; a zone of thick-skinned complex deformation characterized by backthrusting and backfolding; a marginal basement arch; and, inboard of the arch, a fold-thrust belt that mainly involves thin-skinned deformation.
Download or read book Thick skinned South verging Backthrusting in the Felch and Calumet Troughs Area of the Penokean Orogen Northern Michigan written by John S. Klasner and published by . This book was released on 1993 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by United States. Superintendent of Documents and published by . This book was released on 1993 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt: February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index
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 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 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 Field Trip Guidebooks written by and published by . This book was released on 1998 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Petrography and Geochemistry of Early Proterozoic Granitoid Rocks in Wisconsin Magmatic Terranes of Penokean Orogen Northern Wisconsin written by Paul Kibler Sims and published by . This book was released on 1993 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reconnaissance study carried out in conjunction with regional geologic mapping.
Download or read book Archean and Early Proterozoic Tectonic Framework of North Central United States and Adjacent Canada written by Paul Kibler Sims and published by . This book was released on 1995 with total page 20 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 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 Proceedings and Abstracts for the Annual Institute on Lake Superior Geology written by and published by . This book was released on 2003 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tectonic Imbrication and Foredeep Development in the Penokean Orogen East central Minnesota an Interpretation Based on Regional Geophysics and the Results of Test drilling written by David Leroy Southwick and published by . This book was released on 1992 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Felch and Calumet troughs area of northern Michigan is part of the Penokean fold-thrust belt of the continental foreland of the Superior craton. The area lies immediately north of the Niagara fault zone, the north-verging suture between the continental foreland and the Early Proterozoic Wisconsin magmatic terranes to the south. Accretion of the magmatic terranes to the continental margin approximately equals 1,850 Ma produced south-verging backthrusting and backfolding in this region involving both Archean basement and Early Proterozoic supracrustal strata. Evidence for backthrusting exists throughoutthe Felch and Calumet troughs area. The backthrusting is characterized by southward-overturned bedding and small-scale, south-verging asymmetric folds with a subhorizontal axial-planar foliation. The Carney Lake Archean block appears to be a crystalline-core nappe wherein the Sturgeon Quartzite of the Chocolay Group forms the lower overturned limb. The deformation probably started as a north-verging foreland thrust event, but out-of- sequence south-verging backthrusts and backfolds developed to accommodate abrupt changes in crustal thickness along the continental margin. The backthrusting in the Penokean orogen resembles that in the younger rocks of the southern Alps. Proceeding inward from the continental margin, both orogens have accreted oceanic crust, indicated by the presence of ophiolite, that is thrust onto the continental margin; a zone of thick-skinned complex deformation characterized by backthrusting and backfolding; a marginal basement arch; and, inboard of the arch, a fold-thrust belt that mainly involves thin-skinned deformation.
Download or read book New Publications of the U S Geological Survey written by Geological Survey (U.S.) and published by . This book was released on 1993 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
