Kink-Band Folding, Valley and Ridge Province, Pennsylvania

Research Article| April 01, 1973 Kink-Band Folding, Valley and Ridge Province, Pennsylvania RODGER T. FAILL RODGER T. FAILL 1Pennsylvania Geological Survey, Harrisburg, Pennsylvania 17120 Search for other works by this author on: GSW Google Scholar Author and Article Information RODGER T. FAILL 1Pennsylvania Geological Survey, Harrisburg, Pennsylvania 17120 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1973) 84 (4): 1289–1314. https://doi.org/10.1130/0016-7606(1973)84<1289:KFVARP>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation RODGER T. FAILL; Kink-Band Folding, Valley and Ridge Province, Pennsylvania. GSA Bulletin 1973;; 84 (4): 1289–1314. doi: https://doi.org/10.1130/0016-7606(1973)84<1289:KFVARP>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract It has become generally accepted that the Alleghanian deformational structures in the Valley and Ridge province of the central Appalachians were produced by northwestward movement of the Paleozoic rocks on décollements at depth. The folds in central Pennsylvania represent conversion of transport on the décollements into deformation of the overlying moving block. Abundant slicken-sides on bedding surfaces and constant bed-normal thicknesses indicate that they are flexural slip folds. But they are not concentric in profile. Rather, the folds possess planar limbs and narrow hinges. The presence of large and small kink bands, and the similarity of geometry (large zones of constant bed orientation, abrupt changes in bed attitude) and deformational mechanism of kink bands and these folds indicate a genetic relation. That is, kink bands can be combined to produce all the observed varieties of fold profiles. Thus, the folds in this province appear to be a widespread, large-scale kink-band deformation.In cylindrical kink-band folds, bedding in both limbs has been rotated about the same axis. The presence of two differently oriented slickenside sets on single bedding surfaces indicates that in many of the folds, each limb has been rotated about a different axis. The resulting fold geometry is noncylindrical, giving rise to the doubly plunging, en echelon, and other complex folds that are prevalent in the province. These noncylindrical structures, reflecting a pervasive interfingering of kinematic domains (kink bands) of different orientations, constitute the regional arcuation of the Valley and Ridge folds in Pennsylvania. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.