What was the early theory of continental drift?
Continental drift was a theory that explained how continents shift position on Earth’s surface. Set forth in 1912 by Alfred Wegener, a geophysicist and meteorologist, continental drift also explained why look-alike animal and plant fossils, and similar rock formations, are found on different continents.
What German scientist first proposed the theory of continental drift in 1912 hypothesizing that the continents moved around the Earth?
Alfred Wegener
Who was the German scientist credited with the theory of continental drift?
Alfred Lothar Wegener
Where did early recognition of continental drift come from?
Alfred Wegener first presented his hypothesis to the German Geological Society on 6 January 1912. His hypothesis was that the continents had once formed a single landmass, called Pangaea, before breaking apart and drifting to their present locations.
Why was Pangea not accepted?
Despite having this geological and paleontological evidence, Wegener’s theory of continental drift was not accepted by the scientific community, because his explanation of the driving forces behind continental movement (which he said stemmed from the pulling force that created Earth’s equatorial bulge or the …
What are the 4 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.
How fast did Pangea break apart?
This is most dramatically seen between North America and Africa during Pangea’s initial rift some 240 million years ago. At that time, the slabs of rock that carried these present-day continents crawled apart from each other at a rate of a millimeter a year. They remained in this slow phase for about 40 million years.
What is the best piece of evidence for plate tectonics?
Evidence from fossils, glaciers, and complementary coastlines helps reveal how the plates once fit together. Fossils tell us when and where plants and animals once existed. Some life “rode” on diverging plates, became isolated, and evolved into new species.
What is the evidence for Pangea?
Glacial deposits, specifically till, of the same age and structure are found on many separate continents that would have been together in the continent of Pangaea. Fossil evidence for Pangaea includes the presence of similar and identical species on continents that are now great distances apart.
What are the 3 major pieces of evidence for Pangea?
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 are the four pieces of evidence for Pangaea?
Terms in this set (4)
- Fossil Correlation. unique remains in distant places.
- Rock Correlation. identical rocks, mountains and structures.
- Apparent Fit. continents look like puzzle pieces and seem to fit together.
- Paleoclimate Data. coal found in cold regions, glacial evidence found in warm regions.
What are 2 pieces of evidence for plate tectonics?
There is variety of evidence that supports the claims that plate tectonics accounts for (1) the distribution of fossils on different continents, (2) the occurrence of earthquakes, and (3) continental and ocean floor features including mountains, volcanoes, faults, and trenches.
What is the force that moves the continents?
The movement of these tectonic plates is likely caused by convection currents in the molten rock in Earth’s mantle below the crust. Earthquakes and volcanoes are the short-term results of this tectonic movement. The long-term result of plate tectonics is the movement of entire continents over millions of years (Fig.
What are the evidence of seafloor spreading?
Abundant evidence supports the major contentions of the seafloor-spreading theory. First, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge.
What are the 3 pieces of evidence for seafloor spreading?
Look at Figure 19 to see the process of sea-floor spreading. Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material, magnetic stripes, and drilling samples. This evidence also led sci- entists to look again at Wegener’s theory of continental drift.
What is the first step of seafloor spreading?
A crack forms in oceanic crust. Molten rock rises up through oceanic crust. Molten rock solidifies at the center of the ridge.
What is the importance of seafloor spreading?
Today it refers to the processes creating new oceanic lithosphere where plates move apart. Seafloor spreading replaces the lithosphere destroyed by subduction, and exerts important influences on Earth’s chemical and biological evolution.
What is the importance of seafloor spreading How does it affect the earth?
Mid-ocean ridges and seafloor spreading can also influence sea levels. As oceanic crust moves away from the shallow mid-ocean ridges, it cools and sinks as it becomes more dense. This increases the volume of the ocean basin and decreases the sea level.
What are the features of seafloor?
Features of the ocean include the continental shelf, slope, and rise. The ocean floor is called the abyssal plain. Below the ocean floor, there are a few small deeper areas called ocean trenches. Features rising up from the ocean floor include seamounts, volcanic islands and the mid-oceanic ridges and rises.
Where is active seafloor spreading occurring today?
Where is active sea floor spreading occurring today? Seafloor spreading is the movement of old rock that is being pushed by the new young oceanic crust. This would be a divergent since the plates are separating from each other. Active seafloor spreading is occurring at mid-ocean ridges.
Which boundary is seafloor destroyed?
COnvergent Boundary
What causes tectonic plates to move?
The heat from radioactive processes within the planet’s interior causes the plates to move, sometimes toward and sometimes away from each other. This movement is called plate motion, or tectonic shift.
Who proposed seafloor spreading?
Harry Hess
Where is seafloor destroyed?
You are correct that the seafloor is destroyed at subduction zones, but it is simultaneously being created at mid-ocean ridges. see figure 1 . Figure 1: Seafloor spreading at a mid-ocean ridge(where new crust is being created) and it’s destruction at a subduction zone.
Where is the oldest seafloor found?
Mediterranean Sea
Who first discovered seafloor spreading and what was the new technology used?
Why was Continental Drift rejected?
The main reason that Wegener’s hypothesis was not accepted was because he suggested no mechanism for moving the continents. He thought the force of Earth’s spin was sufficient to cause continents to move, but geologists knew that rocks are too strong for this to be true.
How does seafloor spreading prove continental drift?
Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere. At a spreading center, basaltic magma rises up the fractures and cools on the ocean floor to form new seabed.
What process recycles the crust?
Crustal recycling is a tectonic process by which surface material from the lithosphere is recycled into the mantle by subduction erosion or delamination.