Research Article| March 01, 1975 Paleomagnetism of Miocene Volcanic Rocks of Guam and the Curvature of the Southern Mariana Island Arc: JAPAN–UNITED STATES PALEOMAGNETISM PROJECT IN MICRONESIA E. E. LARSON; E. E. LARSON 1Cooperative Institute for Research in Environmental Sciences and Department of Geological Sciences, University of Colorado, Boulder, Colorado 80302 Search for other works by this author on: GSW Google Scholar R. L. REYNOLDS; R. L. REYNOLDS 1Cooperative Institute for Research in Environmental Sciences and Department of Geological Sciences, University of Colorado, Boulder, Colorado 80302 Search for other works by this author on: GSW Google Scholar M. OZIMA; M. OZIMA 2Geophysical Institute, University of Tokyo, Tokyo, Japan Search for other works by this author on: GSW Google Scholar Y. AOKI; Y. AOKI 2Geophysical Institute, University of Tokyo, Tokyo, Japan Search for other works by this author on: GSW Google Scholar H. KINOSHITA; H. KINOSHITA 2Geophysical Institute, University of Tokyo, Tokyo, Japan Search for other works by this author on: GSW Google Scholar S. ZASSHU; S. ZASSHU 2Geophysical Institute, University of Tokyo, Tokyo, Japan Search for other works by this author on: GSW Google Scholar N. KAWAI; N. KAWAI 3Department of Material Science, University of Osaka, Osaka, Japan Search for other works by this author on: GSW Google Scholar T. NAKAJIMA; T. NAKAJIMA 3Department of Material Science, University of Osaka, Osaka, Japan Search for other works by this author on: GSW Google Scholar K. HIROOKA; K. HIROOKA 4Geological Laboratory, Fukui University, Fukui, Japan Search for other works by this author on: GSW Google Scholar R. MERRILL; R. MERRILL 5Geophysics Group, University of Washington, Seattle, Washington 98105 Search for other works by this author on: GSW Google Scholar S. LEVI S. LEVI 5Geophysics Group, University of Washington, Seattle, Washington 98105 Search for other works by this author on: GSW Google Scholar Author and Article Information E. E. LARSON 1Cooperative Institute for Research in Environmental Sciences and Department of Geological Sciences, University of Colorado, Boulder, Colorado 80302 R. L. REYNOLDS 1Cooperative Institute for Research in Environmental Sciences and Department of Geological Sciences, University of Colorado, Boulder, Colorado 80302 M. OZIMA 2Geophysical Institute, University of Tokyo, Tokyo, Japan Y. AOKI 2Geophysical Institute, University of Tokyo, Tokyo, Japan H. KINOSHITA 2Geophysical Institute, University of Tokyo, Tokyo, Japan S. ZASSHU 2Geophysical Institute, University of Tokyo, Tokyo, Japan N. KAWAI 3Department of Material Science, University of Osaka, Osaka, Japan T. NAKAJIMA 3Department of Material Science, University of Osaka, Osaka, Japan K. HIROOKA 4Geological Laboratory, Fukui University, Fukui, Japan R. MERRILL 5Geophysics Group, University of Washington, Seattle, Washington 98105 S. LEVI 5Geophysics Group, University of Washington, Seattle, Washington 98105 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1975) 86 (3): 346–350. https://doi.org/10.1130/0016-7606(1975)86<346:POMVRO>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 MailTo Tools Icon Tools Get Permissions Search Site Citation E. E. LARSON, R. L. REYNOLDS, M. OZIMA, Y. AOKI, H. KINOSHITA, S. ZASSHU, N. KAWAI, T. NAKAJIMA, K. HIROOKA, R. MERRILL, S. LEVI; Paleomagnetism of Miocene Volcanic Rocks of Guam and the Curvature of the Southern Mariana Island Arc: JAPAN–UNITED STATES PALEOMAGNETISM PROJECT IN MICRONESIA. GSA Bulletin 1975;; 86 (3): 346–350. doi: https://doi.org/10.1130/0016-7606(1975)86<346:POMVRO>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 Directions of paleomagnetism in dikes and flows in Miocene age on Guam (lat. 13.3° N., long. 144.7° E.) deviate considerably but systematically from the present Earth field direction. The mean inclination of the eight sites is 24° (downward), which is nearly exactly that of the axial dipolar field for this latitude; but the mean declination lies 55° clockwise from true north (α95 = 21°). A simple explanation is that the southernmost portion of the Mariana island arc has been tectonically rotated about a vertical axis in a clockwise direction about 50° to 60° since Miocene time but has undergone little, if any, latitudinal shifting. These conclusions are also consistent with available interpretations of seismic data for the southern Mariana arc which suggest components of right-lateral strike slip as well as thrust movement along the generally east-west zone separating the Philippine Sea plate on the north from the Pacific plate on the south. 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.