Download or read book Nature and Style of Deformation in the Foreland of the Early Proterozoic Penokean Orogen Northern Michigan written by J. S. Klasner and published by . This book was released on 1991 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evidence for Early Proterozoic north-verging folding and thrusting in the continental foreland of the Penokean orogen is present in two widely separated areas in northern Michigan. In the eastern part of the exposed orogen, asymmetric to over-turned folds in the Early Proterozoic Michigamme Formation suggest an initial (D1) phase of possibly north verging thin-skinned deformation. A second phase (D2 ) is characterized by a more thick skinned deformation consisting of northward thrusting of Archean gneiss and overlying Early Proterozoic quartzite along ductile thrust faults. Crosscutting shear zones indicate a third phase (D3 ) of deformation involving east- northeast thrusting of Archean gneiss. Thick-skinned deformation D2 and D3 phases include spaced fracture cleavage, kink folds, and lineations in D1, foliation surfaces. Near the west end of the exposed orogen in Michigan, bedding-cleavage relationships in the Early Proterozoic Tyler Formation also indicate northward tectonic transport. These structures, which are interpreted as D1 lie along the north edge of the Archean Puritan batholith and associated Archean greenstone. The north-verging structures in the northern Michigan segment of the Penokean orogen were formed approximately 1,850 Ma during collision of the Wisconsin magmatic terranes with the continental foreland of Michigan, Wisconsin, and Minnesota.

Download or read book Nature and Style of Deformation in the Foreland of the Early Proterozoic Penokean Orogen Northern Michigan written by J.S. Klasner and published by . This book was released on 1991 with total page 22 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 New Publications of the U S Geological Survey written by and published by . This book was released on 1991 with total page 372 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 Canadian Journal of Earth Sciences written by and published by . This book was released on 2002 with total page 1134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on with total page 1112 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 New Publications of the Geological Survey written by Geological Survey (U.S.) and published by . This book was released on 1991 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guide to USGS Publications written by and published by . This book was released on 1998 with total page 1660 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Field Trip Guidebooks written by and published by . This book was released on 2008 with total page 208 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 Monthly Catalogue United States Public Documents written by and published by . This book was released on 1992 with total page 1384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliography and Index of Geology written by and published by . This book was released on 1992 with total page 1404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology of the Lake Superior Region written by Gene L. LaBerge and published by Tucson, Ariz. : Geoscience Press. This book was released on 1994 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Considered one of the classic geologic areas of the world, the Lake Superior region is one of the most interesting geological areas in North America. An excellent resource for the reader, this book includes examples, photos, maps, and diagrams of the geology of this region.

Download or read book Proceedings written by and published by . This book was released on 1996 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.