Procedures In Field Geology

Procedures in FIELD GEOLOGY Tom Freeman Distinguished Teaching Professor Emeritus University of Missouri-Columbia b Blackwell Science Procedures in FIELD GEOLOGY Tom Freeman Distinguished Teaching Professor Emeritus University of Missouri-Columbia b Blackwell Science ii (c)1999 by Tom Freeman Blackwell Science. Inc. Editorial Offices: Commerce Place, 350 Main Street, Malden, Massachusetts 02148, USA Osney Mead, Oxford OX2 OEl, England 25 John Street, London WC1 N2BL, England 23 Ainslie Place, Edinburgh EH3 6AJ, Scotland 54 University Street, Carlton, Victoria 3053, Australia Blackwell Wissenschafts-Verlag GmbH, KurfOrstendamm 57, 10707 Berlin. Germany Blackwell Science KK, MG Kodenmacho Building, 7-10 Kodenmacho Nihombashi, Chuo-ku, Tokyo 104, Japan Distrlbutors: USA Blackwell Science, Inc. Commerce Place 350 Main Street Malden, Massachusetts 02148 (Telephone orders: 800-215-1000 or 781-388-8250; fax orders: 781-388-8270) Canada Login Brothers Book Company 324 Saulteaux Crescent Winnipeg, Manitoba, R3J 3T2 (Telephone orders: 204-224-4068) Australia Blackwell Science Pty, Ltd. 54 University Street Carlton, Victoria 3053 (Telephone orders: 03-9347-0300; fax orders: 03-9349-3016) Outside North America and Australia Blackwell Science, Ltd. cia Marston Book Services, ltd. P.O. Box 269 Abingdon Oxon OX14 4YN England (Telephone orders: 44-01235-465500; fax orders: 44-01235-465555) All rights reserved. No part of this book may be reproduced in any form or by any electronic or mechanical means, including information storage and retrieval systems, without permission in writing from the publisher, except by a reviewer who may quote brief passages in a review. 0-86542-008-4 Printed in the United States of America 99 00 01 02 5 4 3 2 1 The Blackwell Science logo is a trade mark of Blackwell Science ltd., registered at the United Kingdom Trade Marks Registry iii Preface My purpose in writing this manual is to provide a pocket-size presentation of field procedures without the bulk and cost of a comprehensive textbook. The first part, Tools of the Trade, covers the Brunton compass and Jacob's staff, the Silva compass, and the plane table and alidade-along with principles of map direction and strike and dip. Also, I have included a section on uses of the stereographic net for those who lack hardware and software necessary for the manipulation of field measurements. A second part, Things to Do, presents a variety of procedures commonly undertaken in geologic field courses. The third part, Reference Stuff, provides basic information on topographic maps, trigonometric solutions, and conventional map patterns and symbols. Field procedures described herein are those that have emerged through years of teaching at our University of Missouri's Camp E.B. Branson in the Wind River Mountains of Wyoming. I welcome suggestions for the inclusion of additional procedures in future editions. Tom Freeman Columbia, Missouri v c o N T E N T S TOOLS OF THE TRADE The Brunton compass 1 But first-two methods of stating direction 1 Bearing (or quadrant) method 1 Azimuth method 2 Brunton anatomy 3 Magnetic declination 4 Magnetic declination defined 4 Adjusting a Brunton for magnetic declination 7 Beware of metal objects! 7 Measuring direction to an object 8 Using a Brunton as a protractor 11 Measuring vertical angles 12 Review-trigonometry of a right-triangle 14 Solving for map distance represented by slope angle and slope distance 15 Solving for difference in elevation represented by slope angle and slope distance 15 Solving for difference in elevation using succesive eye-height measurements 16 Strike and dip-definitions 17 Recording strike with the right-hand rule