ctonostratigraphic Terranes and Tectonic Evolution of Mexico Richard L. Sedlock Department of Geology San Jose State University San Jose, California 95192-0102 Fernando Ortega-Gutierrez Instituto de Geologia Universidad Nacional Aut6noma de Mexico, Apartado 70-296 Mexico 20, D.F. and Robert C. Speed Department of Geological Sciences Northwestern University Evanston, Illinois 60208 SPECIAL PIPER 278 1993 © 1993 The Geological Society of America, Inc. All rights reserved. All materials subject to this copyright and included in this volume may be photocopied for the noncommercial purpose of scientific or educational advancement. Copyright is not claimed on any material prepared wholly by government employees within the scope of their employment. Published by The Geological Society of America, Inc. 3300 Penrose Place, P.O. Box 9140, Boulder, Colorado 80301 Printed in U.S.A. GSA Books Science Editor Richard A. Hoppin Library of Congress Cataloging-in-Publication Data Sedlock, Richard L., 1958– Tectonostratigraphic terranes and tectonic evolution of Mexico / Richard L. Sedlock, Fernando Ortega-Gutierrez, Robert C. Speed. p. cm. — (Special paper ; 278) Includes bibliographical references and index. ISBN 0-8137-2278-0 1. Geology, Structural—Mexico. 2. Geology, Stratigraphic. I. Ortega-Gutierrez, Fernando. II. Speed, Robert C. III. Title. IV. Series: Special papers (Geological Society of America) ; 278. QE629.S43 1993 551.8'0972—dc20 93-3196 CIP Cover photo: View to the southwest of Isla Santa Margarita, Baja California Sur, Mexico; Isla Magdalena in foreground. Both islands are underlain by ophiolitic, arc, and blueschist terranes whose history of amalgamation and displacement may be repre- sentative of the tectonic evolution of most of Mexico. 10 9 8 7 6 5 4 3 2 1 11 Contents Acknowledgments ......................................................................................................... v Abstract ......................................................................................................................... 1 Goals and Overview ..................................................................................................... 2 Part 1: Tectonostratigraphic Terranes of Mexico ............................................................ 2 Morphotectonic Provinces ......................................................................................... 2 Modern Plate Tectonic Framework ........................................................................... 4 Caribbean—North America Plate Boundary ............................................................ 4 Pacific—North America Plate Boundary .................................................................. 4 Cocos—North America and Cocos-Caribbean Plate Boundaries .............................. 5 Rivera—North America Plate Boundary ................................................................. 7 Trans-Mexican Volcanic Belt (TMVB) .................................................................. 7 North American Intraplate Deformation ............................................................... 7 Significance of Regional Geophysical Studies ........................................................ 8 Terrane Descriptions ................................................................................................. 8 Chatino Terrane ................................................................................................... 10 Chortis Terrane ................................................................................................... 11 Coahuiltecano Terrane ......................................................................................... 15 Cochimi Terrane ................................................................................................. 17 Cuicateco Terrane ............................................................................................... 23 Guachichil Terrane ............................................................................................... 25 Maya Terrane ....................................................................................................... 28 Mixteco Terrane ................................................................................................... 34 Nahuatl Terrane ................................................................................................... 37 North America Terrane ....................................................................................... 42 Pericti Terrane ..................................................................................................... 47 Seri Terrane ......................................................................................................... 49 Tahue Terrane ..................................................................................................... 54 Tarahumara Terrane ........................................................................................... 55 Tepehuano Terrane ............................................................................................. 58 Yuma Composite Terrane ................................................................................... 63 Zapoteco Terrane ................................................................................................. 67 Terrane Boundaries ................................................................................................. 68 Boundaries of Tarahumara Terrane ...................................................................... 68 Southern Boundary of North America, Tarahumara, and Coahuiltecano Terranes (Mojave-Sonora Megashear) .............................................................. 69 111 iv Contents Eastern and Southern Boundaries of Seri Terrane ................................................ 70 Cochimi-Yuma Boundary ................................................................................... 70 Yuma-Tahue Boundary (Pre—Gulf of California) .................................................. 70 Boundaries of Pericti Terrane ............................................................................... 70 Tahue-Tepehuano Boundary ............................................................................... 71 Tepehuano-Guachichil Boundary ......................................................................... 71 Guachichil-Maya Boundary ................................................................................. 71 Trans-Mexican Volcanic Belt ............................................................................... 71 Eastern Boundary of Nahuatl Terrane .................................................................. 72 Zapoteco-Mixteco Boundary ............................................................................... 72 Northern Boundary of Chatino Terrane ................................................................ 72 Boundaries of Cuicateco Terrane ......................................................................... 73 Maya-Chortis Boundary ....................................................................................... 73 Part 2: Tectonic Evolution of Mexico ......................................................................... 74 Introduction ............................................................................................................. 74 Premises and Other Constraints ............................................................................... 74 Reference Frame and Time Scale ....................................................................... 74 Southern Margin of Proterozoic North America .................................................. 74 Paleogeography of Pangea in the Vicinity of Mexico ............................................ 76 Origin of Grenville Basement in Mexico .............................................................. 76 Permian-Triassic Arc in Eastern Mexico .............................................................. 77 Late Paleozoic-Cenozoic Strike-Slip Faulting ...................................................... 78 Opening of the Proto-Caribbean and Gulf of Mexico .......................................... 82 Mesozoic and Cenozoic Evolution of Oceanic Plates Bordering Mexico .................. 82 Western Mexico ................................................................................................... 82 Caribbean Region ............................................................................................... 84 Reconstruction of the Tectonic Evolution of Mexico ................................................ 85 Precambrian to Devonian ................................................................................... 85 Devonian and Carboniferous ............................................................................... 88 Carboniferous and Early Permian ....................................................................... 91 Late Permian to Present: Overview ...................................................................... 93 Late Permian to Middle Triassic ......................................................................... 94 Late Triassic to Late Jurassic ............................................................................... 96 Cretaceous to Paleogene ..................................................................................... 105 Cenozoic ........................................................................................................... 114 Summary ..............................................................................................................