identify and describe the fossil evidence wegener used to support the theory continental drift and plate tectonics
Alfred Wegener used various types of fossil evidence to support his theory of continental drift and plate tectonics. The fossil evidence Wegener used can be summarized as follows:
1. Matching Fossil Assemblages: Wegener noticed similar types of fossils were found on adjacent continents, even continents that are separated by vast oceans. For example, he observed that identical plant and animal fossils, such as Glossopteris ferns and Mesosaurus reptiles, were found in South America, Africa, India, Australia, and Antarctica. Wegener argued that these organisms could not have crossed the vast distances of ocean water, suggesting that the continents were likely connected in the past.
2. Similar Paleoclimatic Evidence: Wegener also studied paleoclimatology and discovered that evidence of ancient climates, such as glacial deposits and coal beds, lined up across continents that are now widely separated. He found glacial striations (scratches) that extended across South America, Africa, India, Australia, and Antarctica. Additionally, coal deposits in Antarctica indicated that the region was once located closer to the equator and experienced a tropical climate. Wegener argued that these shared climatic features supported the idea of continent-to-continent connections.
3. The Geological Continuity of Mountain Ranges: Wegener noticed that mountain ranges, such as the Appalachians in North America, lined up with their counterparts in Europe and North Africa, suggesting that they were once part of a single supercontinent. He argued that the similarity in rock types, geological structures, and mountain building events was only possible if the continents had been joined together and subsequently moved apart.
Overall, Wegener's fossil evidence provided strong support for his theory of continental drift and plate tectonics. By examining the distribution of fossils and paleoclimatic indicators across continents, he concluded that the continents were once united in a supercontinent called Pangaea, which later broke apart and drifted to their current positions.