Plate Tectonics, And Continental Drift Quiz

Alfred Wegner named the one large continent Pangaea. This supercontinent existed approximately 300 million years ago and was made up of all the current continents combined. Wegner proposed the theory of continental drift, suggesting that the continents were once connected and have since moved apart. He used geological evidence such as the fit of the continents' coastlines, the distribution of fossils, and the similarity of rock formations to support his theory. The name Pangaea comes from the Greek words "pan" meaning all, and "gaea" meaning earth, representing the idea of a single landmass.

The correct answer is "translate boundary." This is because "translate boundary" is not a recognized type of plate boundary. The three main types of plate boundaries are convergent boundaries, where plates collide; divergent boundaries, where plates move apart; and transform boundaries, where plates slide past each other horizontally.

At a divergent plate boundary, the plates move apart. This occurs when two tectonic plates are moving away from each other, creating a gap in between. As the plates separate, magma rises from the mantle to fill the gap, creating new crust. This process is known as seafloor spreading and is responsible for the formation of mid-ocean ridges. The movement of plates apart at divergent boundaries is a key factor in the theory of plate tectonics and the formation of new crust on Earth's surface.

The correct answer is convection currents. Convection currents refer to the circular movement of heated material within the mantle of the Earth. As the mantle is heated from below by the core, the hot material rises towards the surface, while the cooler material sinks back down. This continuous cycle of heating and cooling creates convection currents, which play a crucial role in the movement of tectonic plates and the process of mantle convection.

The lithosphere is the rigid outer layer of the Earth, consisting of the crust and the uppermost part of the mantle. The crust is the thin, solid outermost layer, while the upper mantle is the layer beneath the crust. Together, they form the lithosphere, which is responsible for the movement of tectonic plates and the formation of landforms on Earth's surface. The other options, such as the inner and outer core, are incorrect as they are deeper layers of the Earth and not part of the lithosphere.

A subduction zone is the correct answer because it refers to the specific area where one tectonic plate is forced beneath another plate during the process of plate tectonics. This occurs when two plates converge, or come together, and one plate is pushed beneath the other due to the difference in density. Subduction zones are characterized by intense geological activity, such as earthquakes and volcanic eruptions, making them important areas for studying the Earth's dynamic processes.

Mesosaurus is the correct answer because its fossil remains were found in both South America and Africa, suggesting that these continents were once connected. This discovery provided evidence for the theory of continental drift, which states that the Earth's continents were once joined together in a single landmass called Pangaea and have since moved apart. The presence of Mesosaurus fossils in both continents supports the idea that they were once connected and later separated.

A transform boundary is the correct answer because it describes a plate boundary where two plates slide past each other horizontally. This type of boundary is characterized by intense friction and shear stress, which can result in earthquakes. Unlike convergent or divergent boundaries, where plates are moving towards or away from each other, a transform boundary does not involve the creation or destruction of crust. Instead, it is solely focused on the horizontal movement of the plates.

Alfred Wegner's theory of continental drift was not accepted because it could not explain how or why the continents were drifting. Despite presenting evidence of similar rock formations and fossils on different continents, Wegner was unable to provide a mechanism that could account for the movement of the continents. This lack of a plausible explanation hindered the acceptance of his theory until the development of plate tectonics in the 1960s, which provided a comprehensive explanation for continental drift.

B is correct because continental crust is less dense than oceanic crust. The lower density of continental crust, which is primarily composed of granite, causes it to float higher on the Earth's mantle compared to the denser, basaltic oceanic crust. This difference in density affects the Earth's geology, including the formation of mountains and ocean basins.

A divergent boundary occurs when two tectonic plates move away from each other. The mid-ocean ridge is a prime example of this as it is a continuous underwater mountain range formed by the separation of two oceanic plates. The San Andreas Fault is a transform boundary where two plates slide past each other horizontally, and the Himalaya Mountains are formed by the collision of two continental plates, making them an example of a convergent boundary.

The correct answer is "found far from the mid ocean ridges." This is because as new oceanic crust is formed at the mid ocean ridges, older crust is pushed away, creating a pattern of younger rocks towards the center and older rocks further away from the ridges.

Volcanoes can form above subduction zones. Subduction zones occur when one tectonic plate is forced beneath another, creating a deep trench. As the subducting plate sinks into the Earth's mantle, it begins to melt due to the intense heat and pressure. This molten rock, or magma, rises to the surface and forms volcanoes. The volcanoes can release the built-up pressure in the Earth's crust through volcanic eruptions, leading to the formation of new land and the release of gases and ash into the atmosphere.

The theory of plate tectonics is not the idea that the continents are slowly drifting further away from each other. This statement is false because plate tectonics explains that the Earth's crust is broken into plates that float on the asthenosphere and that these plates move and interact with each other. The theory combines the seafloor spreading theory, which explains the formation of new oceanic crust at mid-ocean ridges, and the continental drift theory, which explains the movement of continents over time.

When two oceanic plates collide, they create a subduction zone where one plate is forced beneath the other. As the subducting plate sinks into the mantle, it begins to melt, forming magma. This magma rises to the surface, creating a line of volcanic islands known as an island arc. These volcanic islands are formed due to the intense heat and pressure caused by the subduction process. Therefore, the correct answer is "island arc."