Characteristics of continental drift
What were the 4 main evidence of continental drift?
They based their idea of continental drift on several lines of evidence: fit of the continents, paleoclimate indicators, truncated geologic features, and fossils.
What are the 3 continental drift?
The processes of seafloor spreading, rift valley formation, and subduction (where heavier tectonic plates sink beneath lighter ones) were not well-established until the 1960s. These processes were the main geologic forces behind what Wegener recognized as continental drift.
What are the 5 evidence of continental drift?
The evidence for continental drift included the fit of the continents; the distribution of ancient fossils, rocks, and mountain ranges; and the locations of ancient climatic zones.
What is the main idea of continental drift?
Continental drift was a revolutionary theory explaining that continents shift position on Earth’s surface. The theory was proposed by geophysicist and meteorologist Alfred Wegener in 1912, but was rejected by mainstream science at the time.
What is continental drift and plate tectonics?
Plate tectonics is the theory that Earth’s land masses are in constant motion. The realization that Earth’s land masses move was first proposed by Alfred Wegener, which he called continental drift.
What is the conclusion of continental drift?
Wegener took the areas that had been covered by ice sheets and fitted them together around the south pole. HIS CONCLUSION – the continents were once part of a single larger continent that then split apart, drifting to their present positions over the last 300 million years.
How did Alfred Wegener explain the movement of continents?
Alfred Wegener’s curiosity toward the possibility of continental drift came in 1910 after he noticed how Earth’s continents resembled pieces of a jigsaw puzzle. For example, he noted how South America coast correctly lined up with the coast of Northwest Africa.
Who gave the continental drift theory?
In the early 20th Century, Alfred Wegener, a German meteorologist and geophysicist, proposed the Continental Drift theory that partially explained the present arrangement of continents and ocean basins on the Earth.
What are the 3 types of plate tectonic boundaries?
Divergent boundaries — where new crust is generated as the plates pull away from each other. Convergent boundaries — where crust is destroyed as one plate dives under another. Transform boundaries — where crust is neither produced nor destroyed as the plates slide horizontally past each other.
What is the 7 major plates?
There are major, minor and micro tectonic plates. There are seven major plates: African, Antarctic, Eurasian, Indo-Australian, North American, Pacific and South American.
Why is it called Pangea?
Pangea’s existence was first proposed in 1912 by German meteorologist Alfred Wegener as a part of his theory of continental drift. Its name is derived from the Greek pangaia, meaning “all the Earth.”
Who gave the continental drift theory?
The first truly detailed and comprehensive theory of continental drift was proposed in 1912 by Alfred Wegener, a German meteorologist. Bringing together a large mass of geologic and paleontological data, Wegener postulated that throughout most of geologic time there was only one continent, which he called Pangea.
Are there 15 tectonic plates?
There are a total of seven major tectonic plates which cover nearly 95% of the Earth’s surface.
Which plate is the smallest?
The Juan de Fuca Plate
The Juan de Fuca Plate is the smallest of earth’s tectonic plates. It is approximately 250,000 square kilometers. It is located west of Washington State and British Columbia, under the Pacific Ocean.
How many plates did you see?
How Many Tectonic Plates are there? Scientists identify 7 major tectonic plates. In order from largest to smallest they are: the Pacific Plate, the North American Plate, the Eurasian Plate, the Antarctic Plate, the Indo-Australian Plate, and the South American Plate.
How many plates does Earth have?
Earth’s crust, called the lithosphere, consists of 15 to 20 moving tectonic plates. The plates can be thought of like pieces of a cracked shell that rest on the hot, molten rock of Earth’s mantle and fit snugly against one another.
How thick is the crust?
Global observations show that the crustal thickness varies through the tectonic regions. While the continental crust is 30–70 km thick, the oceanic crustal thickness is 6–12 km. The oceanic crust is also denser (2.8–3.0 g/cm3) than the continental crust (2.6–2.7 g/cm3).
How heavy is a tectonic plate?
From the figures above, the mass of the plate is 2.85 × 1022 kg.