Publication Date

1969

Document Type

Dissertation/Thesis

First Advisor

Casella, Clarence J.||Morris, Robert C. (Robert Clarence), 1928-

Degree Name

M.S. Ed. (Master of Education)

Department

Department of Earth Science

LCSH

Continental drift

Abstract

The concept of continental movement and rearrangements appears to be very old, but the present theory of continental drift originated only 50 years ago. This theory lacked support because there was no explanation of the force capable of moving continental land masses. Recent study has provided new information about the earth's interior. Some of this suggests that the driving forces are convection currents moving under the earth's crust. Studies of earthquakes, heat flow, magnetic anomalies mid-ocean ridges, island arcs and trenches have caused renewed investigation of the older items of evidence for the theory. Research in paleomagnetism has resulted in efforts to plot wandering curves for the magnetic poles of the earth. These have been used to reconstruct continental movements. Oceanographic studies have increased information about fissures in the ocean floor, ocean ridge and the ages of oceanic islands. Parallel bands of ocean floor material with alternate normal and reverse magnetic polarity may be moving away from the mid-ocean ridges, pushing continental masses away from one another. Latest computer research has shown a low percent of error (less than 3%) in matching edges of continental shelves. Finally, radiometric techniques of rock dating also point to former continental linkage. This all supports the theory of continental drift. Some of the arguments against the theory of continental drift are also reviewed. The final decision to accept this theory may be some years away, and may take the co-operation of many geologists. Most scientists agree that a permanent value of the controversy has been the stimulation of keener observations concerning the fundamental properties of the continents and ocean floors and the behavior of the earth's lower crust and mantle.

Comments

Includes bibliographical references.||Includes illustrations and maps.

Extent

viii, 95 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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