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September Gsat 03 Call for Nominations: 2009 GSA Division Awards, p. 14 VOL. 18, No. 12 A PUBLICATION OF THE GEOLOGICAL SOCIETY OF AMERICA DECEMBER 2008 The Rheic Ocean: Origin, Evolution, and Signifi cance Inside: Upcoming Award, Recognition & Grant Deadlines, p. 16 GSAGSA AdoptsAdopts NewNew StrategicStrategic Plan,Plan, p. 18 SectionSection Meetings:Meetings: CordilleranCordilleran Section,Section, p.p. 2424 South-CentralSouth-Central Section,Section, p.p. 2626 It’s Not Just Software. It’s RockWare. For Over 24 Years. 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GWB Professional $7,999 1D/2D Reactive Transport Modeling $599 Workbench The Geochemist’s Since 1983 303.278.3534 • 800.775.6745 RockWare.com GSATodayDec08.indd 1 10/21/2008 2:17:49 PM VOLUME 18, NUMBER 12 ▲ DECEMBER 2008 SCIENCE ARTICLE GSA TODAY publishes news and information for more than 21,500 GSA members and subscribing libraries. GSA TODAY (ISSN 1052-5173 USPS 0456-530) is published 11 times per 4 The Rheic Ocean: year, monthly, with a combined April/May issue, by The Origin, Evolution, and Signifi cance Geological Society of America®, Inc., with offices at 3300 Penrose Place, Boulder, Colorado. Mailing address: P.O. Box R. Damian Nance and Ulf Linnemann 9140, Boulder, CO 80301-9140, USA. Periodicals postage paid at Boulder, Colorado, and at additional mailing offices. Cover: Recumbent chevron folds in Early Pennsylva- Postmaster: Send address changes to GSA Today, GSA Sales nian graywacke and shale of the Bude Formation at and Service, P.O. Box 9140, Boulder, CO 80301-9140. GSA Millook Haven on the north coast of Cornwall, south- provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of western Britain, record the development and deforma- their race, citizenship, gender, religion, or political viewpoint. tion of the Varsican foreland basin—testifying to the Opinions presented in this publication do not reflect official closure of the Rheic Ocean during the mid- to Late positions of the Society. Pennsylvanian Variscan orogeny. See “The Rheic Ocean: Origin, Evolution, and Significance” by R.D. Copyright © 2008, The Geological Society of America (GSA). All rights reserved. Copyright not claimed on content prepared Nance and U. Linnemann, p. 4–12. wholly by U.S. government employees within scope of their employment. Individual scientists are hereby granted permission, without fees or further requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in other subsequent works and to make unlimited photocopies of items in this journal for noncommercial use in classrooms to further education and science. For any other use, contact 13 Letter Permissions, GSA, P.O. Box 9140, Boulder, CO 80301-9140, USA, Fax +1-303-357-1073, [email protected]. 14 Call for Nominations: 2009 GSA Division Awards SUBSCRIPTIONS for 2008 calendar year: Society Members: 15 Call for Applications: 2009–2010 GSA-USGS Congressional GSA Today is provided as part of membership dues. Contact Science Fellowship GSA Sales and Service at +1-888-443-4472, +1-303-357-1000, option 3, or [email protected] for membership 16 Upcoming Award, Recognition & Grant Deadlines information. Nonmembers & Institutions: Free with paid subscription to both GSA Bulletin and Geology, otherwise 18 GSA Adopts New Strategic Plan US$60. Contact Subscription Services at +1-800-627-0629 or [email protected]. Also available on an annual CD-ROM 22 Call for Proposals: 2009 GSA Annual Meeting, “From Volcanoes to (with GSA’s journals, GSA Data Repository, and an Electronic Retrospective Index to journal articles from 1972); US$99 to Vineyards: Living with Dynamic Landscapes” GSA Members, others call GSA Subscription Services for prices and details. Claims: For nonreceipt or for damaged 24 2009 GSA Section Meeting Calendar copies, members contact GSA Sales and Service; all others contact Subscription Services. Claims are honored for one 24 Preliminary Announcement and Call for Papers: year; please allow sufficient delivery time for overseas copies, Cordilleran Section Meeting up to six months. 25 2009 GSA Section Meeting Mentor Programs GSA TODAY STAFF: Executive Director and Publisher: John W. Hess 26 Final Announcement and Call for Papers: Science Editors: Stephen T. Johnston, University of Victoria, South-Central Section Meeting School of Earth & Ocean Sciences, Victoria, British Columbia V8W 3P6, Canada, [email protected]; and 28 GSA Foundation Update David E. Fastovsky, University of Rhode Island, Department of Geosciences, Woodward Hall, Rm. 317, 29 About People and In Memoriam Kingston, Rhode Island 02881, USA, [email protected]. Managing Editor: Kristen E. Asmus, [email protected] 31 Classified Advertising Graphics Production: Margo Y. Sajban 39 Journal Highlights and Coming Soon to GSA Today ADVERTISING: Classifieds & Display: Ann Crawford, +1-800-472-1988, ext. Erratum 1053, +1-303-357-1053, Fax +1-303-357-1070; The August GSA Today (v. 18, no. 8, p. 17) included periods with the initials [email protected] “W J” for William John McGee. According to two GSA Fellows, “in later years,” GSA ONLINE: www.geosociety.org McGee preferred his first and middle names to be represented by initials only, with no periods. Printed in the USA using pure soy inks. We’d like to hear from you: Information like that provided by these two GSA Fellows is invaluable to accuracy and the preservation of Society history — if you see errors in GSA Today, please contact the managing editor at kasmus@ geosociety.org so that we can make the correction and set the record straight! Thanks. GSA celebrates our three-year association with the International Year of Planet Earth. The Rheic Ocean: Origin, Evolution, and Significance R. Damian Nance, Department of Geological Sciences, 316 that played the dominant role in creating the Appalachian- Clippinger Laboratories, Ohio University, Athens, Ohio Ouachita orogen, and an important record of its history may be 45701, USA, [email protected]; Ulf Linnemann, Staatliche preserved in Mexico. Naturhistorische Sammlungen Dresden, Museum für Mineralogie und Geologie, Königsbrücker Landstraße 159, INTRODUCTION D-01109 Dresden, Germany The Rheic Ocean—named for the Titan, Rhea, sister to Iape- tus in Greek mythology—is arguably the most important ocean of the Paleozoic. Following the Silurian closure of the Iapetus ABSTRACT Ocean, the Rheic Ocean separated the major paleocontinents The Rheic Ocean, which separated Laurussia from Gond- wana after the closure of Iapetus, was one of the principal oceans of the Paleozoic. Its suture extends over 10,000 km from Middle America to Eastern Europe, and its closure assem- bled the greater part of Pangea with the formation of the Ouachita-Alleghanian-Variscan orogen. The Rheic Ocean opened in the Early Ordovician, following protracted Cambrian rifting that represented a continuum of Neoproterozoic orogenic processes, with the separation of sev- eral Neoproterozoic arc terranes from the continental margin of northern Gondwana. Separation likely occurred along a former Laurentia Neoproterozoic suture in response to slab pull in the outboard Iapetus Ocean. The Rheic Ocean broadened at the expense of Baltica Iapetus and attained its greatest width (>4000 km) in the Silu- Avalonia-Carolina rian, by which time Baltica had sutured to Laurentia and the Rheic Ocean Neoproterozoic arc terranes had accreted to Laurussia, closing Iapetus in the process. Closure of the Rheic Ocean began in the Cadomia Devonian and was largely complete by the Mississippian as Gondwana and Laurussia sutured to build Pangea. In this pro- cess, North Africa collided with southern Europe to create the Variscan orogen in the Devono-Carboniferous, and West Africa Gondwana and South America sutured to North America to form the Alleghanian and Ouachita orogens, respectively, during the Permo-Carboniferous. Figure 1. Early Silurian reconstruction of the Rheic Ocean immediately The Rheic Ocean has long been recognized as the major prior to the closure of Iapetus by way of subduction beneath Laurentia Paleozoic ocean in southern Europe, where its history domi- (toothed red line). Stippled areas denote inferred regions
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