文档介绍：Chapter 2: Global Tectonics Our Dynamic
Introduction
Each rocky body, whether or moon, started with a hot interior.
Each has been kept warm over time by energy released by the decay of radioactive isotopes.
Despite radioactive heating, rocky bodies have cooled considerably since their formation, so that their outer layers have stiffened into lithospheres (岩石圈).
Introduction (2)
The interior of Earth remains hot and geologically active.
The mantles of Earth loses internal heat by convection (對流), the slow flow of solid rock.
Hot rock rises upward to near the surface.
Earth’s stiff lithosphere is broken into a collection of near-rigid plates.
Introduction (3)
Most large-scale geologic events, like earthquakes or volcanic eruptions, originate within Earth’s interior.
Many other processes in the Earth system, such as the hydrologic and biogeochemical cycles, are profoundly affected by plate tectonics (板塊運動).
Plate Tectonics (板塊學說): From Hypothesis to Theory
Plate tectonics is a scientific theory that explains two centuries of often puzzling observations and hypotheses about our Earth.
The continents are drifting very slowly across the face of our .
Continental drift (大陸漂移) is a concept with a long history.
Plate Tectonics: From Hypothesis to Theory (2)
A century ago geologists puzzled over the fit of the shorelines of Africa and South America.
They noted that fossils of extinct land-bound plants and animals, glacial deposits (冰河沉積), and ancient lava flows (熔岩流) could be matched together along coastlines that today are thousands of kilometers apart.
Coal was found in Antarctica.
Coal forms in tropical climates, implying that Antarctica has moved in the past.
Plate Tectonics: From Hypothesis to Theory (3)
Alfred Wegener proposed the prehensive early hypothesis for “Continental Drift (大陸漂移假說) ” in 1912.
His theory was widely rejected because:
Ocean floor was too strong to be plowed aside.
Wegener had not proposed a plausible force that could induce the cont