G10-L2 - Continental Drift Theory PDF

LESSON 2 LEARNING TARGETS: Define continental drift theory Describe the pieces of evidence of the Continental Drift Theory When technology advances and accurate maps became available, geologists have realized that Earth’s surfaces is, in fact, a dynamic moving body. If you look closely...

LESSON 2 LEARNING TARGETS: Define continental drift theory Describe the pieces of evidence of the Continental Drift Theory When technology advances and accurate maps became available, geologists have realized that Earth’s surfaces is, in fact, a dynamic moving body. If you look closely at the shapes of the continents on a world map, you may notice that they seem to fit together like pieces of a jigsaw puzzle.  The Dutch geographer and cartographer Abraham Ortelius (1527-1598) first noted this observation in the  German naturalist Alexander Von Humboldt (1769-1859) French scientist Antonio Snider-Pellegrini (1802-1885) American scientist Frank Taylor (1860-1938)  It was only when the German meteorologist and geophysicist Alfred Lothar Wegener (1880- 1930) proposed the idea of the drifting continents in his book The Origin of the Continents and Oceans in 1912 that the jigsaw fit of the continents have started to gain ground in the scientific community.  According to Wegener, a single huge landmass or supercontinent once existed in the distant past. He called this supercontinent Pangaea, a Greek word that means “all lands.” Wegener proposed that Pangaea gradually broke apart into smaller landmasses that started to drift away from one another hundreds of millions of years ago until they reached their present positions.  EVIDENCE FOR CONTINENTAL DRIFT 1. Fossil Records 2. Glacial Striations are scratches or grooves on rocks made by moving glaciers (big sheets of ice). These scratches show the direction that glacier was moving. They help scientists understand that continents have moved because similar scratches are found on rocks in places that are 3. Geologic Features  Geological "fit" evidence is the matching of large- scale geological features on different continents. It has been noted that the coastlines of South America and West Africa seem to match up, however more particularly, the rock terrains of separate continents confirm as well. Examples include the Appalachian Mountains of eastern North America linked with the Scottish Highlands, the familiar rock strata of the Karroo system of South Africa matched correctly with the Santa Catarina system in Brazil, and Brazil and Ghana mountain ranges agreeing over the Atlantic Ocean.