E-Book Content
Canyons Erik Hanson Foreword by Geoffrey H. Nash, Geologist
I dedicate this book to Burton Hanson and to Mathilda. CANYONS Copyright © 2007 by Erik Hanson All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval systems, without permission in writing from the publisher. For information contact: Chelsea House An imprint of Infobase Publishing 132 West 31st Street New York NY 10001 ISBN-10: 0-8160-6435-0 ISBN-13: 978-0-8160-6435-9 Library of Congress Cataloging-in-Publication Data Hanson, Erik A. Canyons / Erik Hanson ; foreword Geoffrey H. Nash. p. cm. — (The extreme earth) Includes index. ISBN 0-8160-6435-0 1. Plate tectonics. 2. Canyons. I. Title II. Series. QE511.4.H36 2007 551.44'2—dc22 2006015810 Chelsea House books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions. Please call our Special Sales Department in New York at (212) 967-8800 or (800) 322-8755. You can find Chelsea House on the World Wide Web at http://www.chelseahouse.com Text design by Erika K. Arroyo Cover design by Dorothy M. Preston/Salvatore Luongo Illustrations by Melissa Ericksen Photo research by Diane K. French Printed in the United States of America VB FOF 10 9 8 7 6 5 4 3 2 1 This book is printed on acid-free paper.
Contents ✧✧✧✧✧✧✧✧✧✧✧✧✧✧✧✧✧✧✧✧✧ Foreword Preface Acknowledgments Introduction
Origin of the Landform: Canyons Setting the Stage: Tectonic Activity Cooperative Effects of Rocks, Water, and Tectonic Activity Effects of Rain and Climate on Canyons The Influence of Rock Layers Submarine Canyons Ten Canyons
ix xi xiii xv
1 2 3 6 10 10 11
1 ✧ The Grand Canyon, Northwestern Arizona, the United States
13
A Framework for Understanding Uplift Deposition and Removal of Mesozoic Sediments Effects of Human-Made Dams Interactions of Plants, Water, and the Sun History of the Colorado River Steep Canyon Walls and Meanders of Rivers Recent Incision, Lava Flows, and Lava Dams Climate in the Present Day Early Prehistory of Northwestern Arizona
15 18 19 20 20 22 23 27 27
2 ✧ The Columbia River Gorge, Northern Oregon and Southern Washington, the United States
30
Origin of the Columbia Plateau Scablands and Cataclysmic Flooding
32 35
Sites and Characteristics of the Eruptions Linear Vents and Focal Points of Eruption Early Versions of Columbia River Gorge Turbulent Flow, Laminar Flow, and Intracanyon Flows The Bridal Veil Channel Joints, Columns, and Layering Patterns in Lava
37 39 39 40 42 43
3 ✧ The Three Gorges of the Yangtze River, Hubei Province and Sichuan Province, Southern China
46
Geological History of the Area Development of the Sichuan and Jianghan Basins Layers of Jurassic and Triassic Rocks Broader Context of the Doming and Volcanic Activity Incision of the Three Gorges Terraces and Cliffs in the Walls of the Gorges The Tibetan Plateau and the Path of the Yangtze River Crustal Thickening, Lithospheric Thickening, and Uplift of Plateaus Changing the Direction of the Middle Yangtze Recent History of Climate Changes Effects of Vegetation Seasonal Rainfall, River Channels, and Desert Formation Karst Formations and the Three Gorges Reservoir Geological Effects of the Reservoir
47 50 52 55 57 58 59 60 60 61 61 62 62 63
4 ✧ Peonera Canyon, Aragón Province, Northeastern Spain
65
Early History of Northeastern Spain Formation of the Pyrenean Range and Ebro Basin Relative Elevation of the Ebro Basin River Flow and the Valencia Trough Flexural Uplift and Intermontane Basins Interactions of Climate Changes and Tectonic Forces Alluvial Fans, Immature Drainage, and Denud