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Geosciences LibreTexts

4.1: Introduction

  • Page ID
    5477
  • Overview

    In chapter one, we reviewed the scientific method and the exact meaning of a theory, which is a well-supported explanation for a natural phenomenon that still cannot be completely proven. A Grand Unifying Theory is a set of ideas that is central and essential to the field of studies such as the theory of gravity in physics or the theory of evolution in biology. The Grand Unifying Theory of geology is the theory of Plate Tectonics, which defines the outer portion of the earth as a brittle outer layer that is broken into moving pieces called tectonic plates. This theory is supported by many lines of evidence including the shape of the continents, the distribution of fossils and rocks, the distribution of environmental indicators, as well as the location of mountains, volcanoes, trenches, and earthquakes. The movement of plates can be observed on human timescales and easily measured using GPS satellites.

    Plate tectonics is integral to the study of geology because it aids in reconstructing earth’s history. This theory helps to explain how the first continents were built, how oceans formed, and even helps inform hypotheses for the origin of life. The theory also helps explain the geographic distribution of geologic features such as mountains, volcanoes, rift valleys, and trenches. Finally, it helps us assess the potential risks of geologic catastrophes such as earthquakes and volcanoes across the earth. The power of this theory lies in its ability to create testable hypotheses regarding Earth’s history as well as predictions regarding its future.

    Key Terms

    • Continental Crust
    • Convergent Boundary
    • Divergent Boundary
    • Grand Unifying Theory
    • Hot Spot
    • Oceanic Crust
    • Ridge Push
    • Slab Pull
    • lab Suction
    • Subduction
    • Tectonic Plates
    • Theory of Plate Tectonics
    • Transform Boundary
    • Wadati-Benioff Zone