German meteorologist Alfred Wegener wasn't the first to observe similarities among the continents that suggested the landmasses might have once been connected. He was the first, however, to gather ideas and evidence into a palpable theory, which he turned into a treatise entitled "The Formation of the Major Features of the Earth's Crust (Continents and Oceans)."
In 1912, at age 32, Wegener must have seemed a brazen upstart to the esteemed members of the Geological Association in Frankfurt and the Society for the Advancement of Natural Science in Marburg when he delivered lectures on his theory that defied the geological thinking of the time, which was based on the contracting-earth theory.
Continental similarities were being explained away with the notion that the continents had once been connected by land bridges. The earth was cooling, according to the theory, and in the process it was contracting, causing sea levels to rise and cover the land bridges.
Like others before him, Wegener noticed that the eastern outline of South America fit the western outline of Africa like pieces of a jigsaw puzzle. He later noticed similar, if imperfect, fits among the other continents. Geologists, paleontologists, and other scientists had collected a good bit of evidence of matching but misplaced rocks, uncovered fossils in places they shouldn't have been, and discovered evidence of astounding climatological changes.
The earth was cooling, according to the theory, and in the process it was contracting, causing sea levels to rise and cover the land bridges.
 |
Key Notes:
- Alfred Wegener was a German Meterorologist
- First to gether ideas and evidence to build drift theory ("The Formation of the Major Features of the Earth's Crust"
- Lectured at Frankfurt for the Geological Association and in Marburg for the Society for the Advancement of Natural Science
- Continents were connected by land bridges
- Lost land bridges when Earth was cooling and contracting - caused sea level to cover them
- Eastern outline of South America fits the Western outline of Africa
- Wegener's Theory's Evidence
- Fossil Evidence: Evidence of organisma on continents separated by large oceans - organisms could not swim
- Geologic Evidence: mountain ranges of similar rock types and structure extend from a continent
- Climate Evidence: glacial evidence in now tropical areas
- Wegener said that the continents formed one land mass called Pangea
HOMEWORK
No comments:
Post a Comment