Large-scale fractures related to inception of the Yellowstone hotspot

Abstract

Research Article| July 01, 2002 Large-scale fractures related to inception of the Yellowstone hotspot Jonathan M.G. Glen; Jonathan M.G. Glen 1U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA, and Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California 94709, USA Search for other works by this author on: GSW Google Scholar David A. Ponce David A. Ponce 2U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Jonathan M.G. Glen 1U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA, and Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California 94709, USA David A. Ponce 2U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, USA Publisher: Geological Society of America Received: 23 Aug 2001 Revision Received: 04 Mar 2002 Accepted: 19 Mar 2002 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2002) 30 (7): 647–650. https://doi.org/10.1130/0091-7613(2002)030<0647:LSFRTI>2.0.CO;2 Article history Received: 23 Aug 2001 Revision Received: 04 Mar 2002 Accepted: 19 Mar 2002 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Jonathan M.G. Glen, David A. Ponce; Large-scale fractures related to inception of the Yellowstone hotspot. Geology 2002;; 30 (7): 647–650. doi: https://doi.org/10.1130/0091-7613(2002)030<0647:LSFRTI>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 SocietyGeology Search Advanced Search Abstract During middle Miocene time, western North America was subject to flood-basalt volcanism, dike-swarm injection, and broad-scale fracturing and folding of the crust. We propose a simple model to account for these events and for a regional pattern of geologic and geophysical features. Aeromagnetic maps reveal some of the most important elements of this pattern, which are several narrow, arcuate anomalies, here referred to as the Northern Nevada rifts. These rifts extend hundreds of kilometers across Nevada and are likely caused by highly magnetic, middle Miocene mafic dikes. With the aid of filtering techniques, the anomalies can be traced into Oregon. Together with other geologic features, such as fold axes, dike swarms, and faults, they produce a spoke-like pattern fanning over 220° of arc that converges toward a point near the Oregon-Idaho border (lat ∼44°N). A possible cause for this pattern is a point source of stress at the base of the crust related to the formation of the Yellowstone hotspot. The spoke-like pattern, however, does not persist at large distances from the emerging hotspot; several hundred kilometers to the south, the Northern Nevada rifts deviate significantly (>30°) from a radial trend. We show that a simple model—imposing a point source of stress at the base of the crust and a regional stress field aligned with the presumed middle Miocene stress direction—fits the observed fracture pattern. It thus accounts for both the radial pattern present near the nascent hotspot and the far-field pattern due to regional stresses. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.