Dynamics of the emplacement of the Heart Mountain allochthon at White Mountain: Constraints from calcite twinning strains, anisotropy of magnetic susceptibility, and thermodynamic calculations

Research Article| May 01, 2009 Dynamics of the emplacement of the Heart Mountain allochthon at White Mountain: Constraints from calcite twinning strains, anisotropy of magnetic susceptibility, and thermodynamic calculations John P. Craddock; John P. Craddock † 1Geology Department, Macalester College, St. Paul, Minnesota 55105, USA †E-mail: craddock@macalester.edu. Search for other works by this author on: GSW Google Scholar David H. Malone; David H. Malone 2Department of Geography-Geology, Illinois State University, Campus Box 4400, Normal, Illinois 61790, USA Search for other works by this author on: GSW Google Scholar Jerry Magloughlin; Jerry Magloughlin 3Department of Geosciences, Colorado State University, Fort Collins, Colorado 80523, USA Search for other works by this author on: GSW Google Scholar Avery L. Cook; Avery L. Cook * 4Geology Department, Macalester College, St. Paul, Minnesota 55105, USA *Present address: Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55405, USA. Search for other works by this author on: GSW Google Scholar Michael E. Rieser; Michael E. Rieser 4Geology Department, Macalester College, St. Paul, Minnesota 55105, USA Search for other works by this author on: GSW Google Scholar James R. Doyle James R. Doyle 5Department of Physics and Astronomy, Macalester College, St. Paul, Minnesota 55105, USA Search for other works by this author on: GSW Google Scholar Author and Article Information John P. Craddock † 1Geology Department, Macalester College, St. Paul, Minnesota 55105, USA David H. Malone 2Department of Geography-Geology, Illinois State University, Campus Box 4400, Normal, Illinois 61790, USA Jerry Magloughlin 3Department of Geosciences, Colorado State University, Fort Collins, Colorado 80523, USA Avery L. Cook * 4Geology Department, Macalester College, St. Paul, Minnesota 55105, USA Michael E. Rieser 4Geology Department, Macalester College, St. Paul, Minnesota 55105, USA James R. Doyle 5Department of Physics and Astronomy, Macalester College, St. Paul, Minnesota 55105, USA †E-mail: craddock@macalester.edu. *Present address: Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55405, USA. Publisher: Geological Society of America Received: 11 Oct 2007 Revision Received: 08 Jul 2008 Accepted: 11 Jul 2008 First Online: 03 Oct 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2009 Geological Society of America GSA Bulletin (2009) 121 (5-6): 919–938. https://doi.org/10.1130/B26340 Article history Received: 11 Oct 2007 Revision Received: 08 Jul 2008 Accepted: 11 Jul 2008 First Online: 03 Oct 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation John P. Craddock, David H. Malone, Jerry Magloughlin, Avery L. Cook, Michael E. Rieser, James R. Doyle; Dynamics of the emplacement of the Heart Mountain allochthon at White Mountain: Constraints from calcite twinning strains, anisotropy of magnetic susceptibility, and thermodynamic calculations. GSA Bulletin 2009;; 121 (5-6): 919–938. doi: https://doi.org/10.1130/B26340 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 White Mountain is centrally located in the bedding-plane portion of the Eocene Heart Mountain detachment and contains the only upper plate Mississippian Madison Group rocks that have been metamorphosed into marble. The marble rests upon the thickest (1 m) part of a carbonate ultracataclasite that marks the detachment. Thermodynamic and mechanical calculations based on possible frictional melting of calcite and other minerals, geochemical data, the characteristics of the carbonate ultracataclasite, and the geometrical characteristics of White Mountain suggest a possible initial upper plate emplacement rate of 126–340 m/sec and that the duration of the emplacement event was less than 4 min, too brief a time to develop an emplacement-related calcite twinning strain overprint in upper or lower plate carbonates. While the detachment-related carbonate ultracataclasite did not form by melting, it does preserve a magnetic fabric where Kmax is parallel to the detachment slip direction and records a westward and down paleopole (287° and 27°), where magnetite is the carrier mineral. The Eocene (49.6 Ma) paleopole for this latitude in North America was southerly and upward (0° and 45°). This brief and catastrophic detachment event produced a significant amount of CO2 by flash heating. This report is the first to quantify the emplacement rate of the upper plate of the Heart Mountain detachment based on physical and geochemical parameters. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.