U.S. Geological Survey Bulletin
Gene L. LaBerge · David Leroy Southwick · J. S. Klasner · J. Warren Beck · Karin M. Barovich · Paul Kibler Sims · Rodney C. Johnson · John Patchett · K. J. Schulz · R. W. Ojakangas · Theodore J. Bornhorst · V. Rama Murthy · Ed DeWitt · Paul E. Myers · Zell E. Peterman · Bruce Brasaemle
Jan 1991 · U.S. Government Printing Office
5.0star
Maoni mojareport
Kitabu pepe
15
Kurasa
reportUkadiriaji na maoni hayajahakikishwa Pata Maelezo Zaidi
Kuhusu kitabu pepe hiki
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.
Ukadiriaji na maoni
5.0
Maoni moja
Kadiria kitabu pepe hiki
Tupe maoni yako.
Kusoma maelezo
Simu mahiri na kompyuta vibao
Sakinisha programu ya Vitabu vya Google Play kwa ajili ya Android na iPad au iPhone. Itasawazishwa kiotomatiki kwenye akaunti yako na kukuruhusu usome vitabu mtandaoni au nje ya mtandao popote ulipo.
Kompyuta za kupakata na kompyuta
Unaweza kusikiliza vitabu vilivyonunuliwa kwenye Google Play wakati unatumia kivinjari cha kompyuta yako.
Visomaji pepe na vifaa vingine
Ili usome kwenye vifaa vya wino pepe kama vile visomaji vya vitabu pepe vya Kobo, utahitaji kupakua faili kisha ulihamishie kwenye kifaa chako. Fuatilia maagizo ya kina ya Kituo cha Usaidizi ili uhamishe faili kwenye visomaji vya vitabu pepe vinavyotumika.
