Continental Drift Flashcards
Who created the Continental drift Theory?
Alfred Wegener
When did the creator of CDT created it?
1912
Explain the CDT
- Continental drift was a theory that explained how continents shift position on Earth’s surface.
- The continents were once joined in a super-continent and have moved over time
What is the supercontinent articulated by the creator of CDT?
What is the meaning of that “word”?
Pangaea (aka all-lands)
What are the evidences of CDT?
- The Continental Jigsaw Puzzle
- Rock Types and Geologic Features
- Fossil Matching Across the Sea
- Ancient Climates
Why did no one believe Wegener’s theory?
He could not explain how the continents moved
What two specific continents fit together most noticeably?
South America and Africa
The Earth’s lithosphere is divided into a number of major and minor tectonic plates. How many major tectonic plates are there?
7
Which tectonic plate below is NOT one of the major tectonic plates?
- Caribbean plate
- North American plate
- Antarctic plate
- Eurasian plate
Caribbean plate
What mountain ranges in Europe and North America serves as evidence of continental drift
theory?
Caledonian and Appalachians
Which explains the rejection of the theory of continental drift before the discovery of seafloor spreading?
Absence of concept explaining the mechanism of plate movements.
Which argument was presented by Wegener’s opponents regarding the distribution of identical fossils of Mesosaurus sp., a freshwater reptile, in South America, Africa, Antarctica, and Australia?
Presence of land bridges, isthmian links that allowed animals to cross vast ocean.
Which freshwater reptile whose fossils were found only in black shales about 260 million years of age (Permian) in South Africa and Brazil?
Mesosaurus
Which is NOT an evidence of continental drift? • Continental jigsaw puzzle • Hieroglyphics of ancient alphabets • rock types and geologic features • Fossil matching across the sea
Hieroglyphics of ancient alphabets
Explain the Continental Jigsaw Puzzle
Suspected that the continents might once have been joined when he noticed the remarkable similarity between the coastlines on opposite sides of the Atlantic Ocean.
Who constructed a map that pieced together the edges of the continental shelves of South America and Africa?
Sir Edward Bullard (early 1960s)
Explain the Rock Types and Geologic Features
Discovered that rocks on both sides of the Atlantic Ocean were identical in terms of type and age. He also matched up mountain ranges with the same rock types, structures, and ages, that were now on opposite sides of the Atlantic Ocean.
Explain the Fossil Matching Across the Sea
Learned that most paleontologists (scientists who study the fossilized remains of ancient organisms) were in agreement that some type of land connection was needed to explain the existence of similar Mesozoic age life-forms on widely separated landmasses. Just as modern life-forms native to North America are quite different from those of Africa and Australia, during the Mesozoic era, organisms on widely separated continents should have been distinctly different.
What are the land reptiles whose fossils were discovered across South America, Africa, India, Antartica.
Lystrosaurus and Cynognathus
Regardless of the flowing information and proofs some geologists suggests that the following must be the reason why fossils of those organisms can be found in different continents. What are the following reasons?
- Rafting
- Isthmian links (transoceanic land bridges)
- Island stepping stones
‘seed fern’ that grew only in a subpolar region, fossils of which were widely distributed over Australia, Africa, India, and South America (later on discovered in Antarctica).
Glossopteris flora
• Learned that these seed ferns grew only in cool climates (similar to central Alaska). Therefore, he concluded that when these landmasses were joined, they were located much closer to the South Pole.
The creator of CDT is also a?
Meteorologist
Explain Ancient Climates
He learned that evidence for a glacial period that dated to the late Paleozoic had been discovered in southern Africa, South America, Australia, and India. This meant that about 300 million years ago, vast ice sheets covered extensive portions of the Southern Hemisphere as well as India.
How could extensive ice sheets form near the equator?
Southern continents are joined together and located near the South Pole. This would account for the conditions necessary to generate extensive expanses of glacial ice over much of these landmasses. At the same time, this geography would place today’s northern continents nearer the equator and account for the tropical swamps that generated the vast coal deposits.
