Author: R. S. MaassPublisher:
ISBN:
Category : Geology
Languages : en
Pages : 70
Book Description
Penokean Deformation and Metamorphism in Central Wisconsin
Author: R. S. MaassEarly Proterozoic Geology of the Great Lakes Region
Author: L. Gordon MedarisPublisher: Geological Society of America
ISBN: 0813711606
Category : Science
Languages : en
Pages : 151
Book Description
The Mountain Shear Zone, Northeastern Wisconsin
Author: Paul Kibler SimsPublisher:
ISBN:
Category : Geology, Stratigraphic
Languages : en
Pages : 24
Book Description
Memoir
Author: Tectonic Imbrication and Foredeep Development in the Penokean Orogen, East-central Minnesota
Author: David Leroy SouthwickPublisher:
ISBN:
Category : Geology
Languages : en
Pages : 40
Book Description
Proceedings
Author: U.S. Geological Survey Bulletin
Author: Nature and Style of Deformation in the Foreland of the Early Proterozoic Penokean Orogen, Northern Michigan
Author: J. S. KlasnerPublisher:
ISBN:
Category : Geology
Languages : en
Pages : 32
Book Description
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.
Pre-Penokean Igneous and Metamorphic Rocks, Benton and Stearns Counties, Central Minnesota
Author: George A. DacrePublisher:
ISBN:
Category : Igneous rocks
Languages : en
Pages : 28
Book Description
Author: