Are the oldest rocks on the seafloor are much younger than the oldest rocks on the continents?
The oldest rocks on the seafloor are much younger than the oldest rocks on the continents. The oldest rocks of the oceanic crust are found in deep ocean trenches far away from active, mid-ocean ridges. In general, rocks of the continental crust are less dense than rocks of the oceanic crust.
Where lithosphere is sinking into the mantle?
When two oceanic lithospheres collide, one runs over the other which causes the latter to sink into the mantle along a zone called a subduction zone. The subducting lithosphere is bent downward to form a very deep depression in the ocean floor called a trench. The deepest ocean in the world is found along trenches.
Where are new oceanic crust and lithosphere formed at?
midocean ridges Oceanic lithosphere forms at midocean ridges, where hot magma upwells, and then cools to form plates as the material moves away from the spreading center. As the plate cools, heat flow decreases and the seafloor deepens (Figure 3).
Which plate boundary is characterized by arcs of volcanoes and deep ocean trenches?
Divergent boundaries are marked by mid-ocean ridges. At divergent boundaries, seafloor Page 2 spreading, a process that forms new oceanic lithosphere, takes place. Convergent boundaries are marked by deep-sea trenches and volcanic arcs.
When compared to the oldest rocks continental the oldest rocks on the ocean floor are quizlet?
The oldest rock in the ocean floor is about 200 million years old. In contrast, the oldest rock in the continents is about 4 billion years old.
Where are the oldest rocks on the seafloor found?
the Mediterranean Sea The oldest seafloor is comparatively very young, approximately 280 million years old. It is found in the Mediterranean Sea and is a remnant of an ancient ocean that is disappearing between Africa and Europe.
What is in the lithosphere?
The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth's structure. It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle) below.
What is in the asthenosphere?
The asthenosphere is a part of the upper mantle just below the lithosphere that is involved in plate tectonic movement and isostatic adjustments. It is composed of peridotite, a rock containing mostly the minerals olivine and pyroxene.
What is called asthenosphere?
asthenosphere, zone of Earth's mantle lying beneath the lithosphere and believed to be much hotter and more fluid than the lithosphere. The asthenosphere extends from about 100 km (60 miles) to about 700 km (450 miles) below Earth's surface.
What is continental and oceanic lithosphere?
Oceanic lithosphere is typically about 50-100 km thick (but beneath the mid-ocean ridges is no thicker than the crust). The continental lithosphere is thicker (about 150 km). It consists of about 50 km of crust and 100 km or more of the uppermost mantle.
Which type of zone is located at a deep ocean trench?
Ocean trenches occupy the deepest layer of the ocean, the hadalpelagic zone. The intense pressure, lack of sunlight, and frigid temperatures of the hadalpelagic zone make ocean trenches some of the most unique habitats on Earth.
What is a divergent boundary?
A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth's mantle to the surface, solidifying to create new oceanic crust.
Where are the oldest rocks found on the seafloor?
The oldest seafloor is comparatively very young, approximately 280 million years old. It is found in the Mediterranean Sea and is a remnant of an ancient ocean that is disappearing between Africa and Europe.
Where are the oldest seafloor rocks found quizlet?
The OLDEST seafloor rocks are found FAR AWAY FROM the mid-ocean ridge.
Where is the oldest seafloor found quizlet?
where is the oldest ocean floor located? the oldest ocean floor is located along in the pacific (farthest from the ridge).
What is the asthenosphere and where is it located?
asthenosphere, zone of Earth's mantle lying beneath the lithosphere and believed to be much hotter and more fluid than the lithosphere. The asthenosphere extends from about 100 km (60 miles) to about 700 km (450 miles) below Earth's surface.
What is in mesosphere?
Most meteors vaporize in the mesosphere. Some material from meteors lingers in the mesosphere, causing this layer to have a relatively high concentration of iron and other metal atoms.
Why is the upper mantle called asthenosphere?
The upper mantle is called asthenosphere, “astheno” is a Greek word meaning 'weak'. It is called weak layer because it is in liquid state where rock material deforms more readily, and magma formation takes place.
Why is the upper mantle called Theasthenosphere?
The upper mantle is called asthenosphere, “astheno” is a Greek word meaning 'weak'. It is called weak layer because it is in liquid state where rock material deforms more readily, and magma formation takes place.
Where is lithosphere and asthenosphere located?
The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth's structure. It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle) below.
What is continental crust and oceanic crust?
Continental crust is typically 40 km (25 miles) thick, while oceanic crust is much thinner, averaging about 6 km (4 miles) in thickness. The effect of the different densities of lithospheric rock can be seen in the different average elevations of continental and oceanic crust.
What is the deep ocean called?
The deepest part of the ocean is called the Challenger Deep and is located beneath the western Pacific Ocean in the southern end of the Mariana Trench, which runs several hundred kilometers southwest of the U.S. territorial island of Guam. Challenger Deep is approximately 10,935 meters (35,876 feet) deep.
What is the deepest zone of the ocean called?
hadalpelagic zone The deepest zone of the ocean, the hadalpelagic zone extends from 19,700 feet (6,000 meters) to the very bottom at 36,070 feet (10,994 meters) in the Mariana Trench off the coast of Japan.
What is continental continental divergent boundary?
A divergent plate boundary on land rips apart continents (Figure below). When plate divergence occurs on land, the continental crust rifts, or splits. This effectively creates a new ocean basin as the pieces of the continent move apart.
What is convergent boundary?
When two plates come together, it is known as a convergent boundary. The impact of the colliding plates can cause the edges of one or both plates to buckle up into a mountain ranges or one of the plates may bend down into a deep seafloor trench.
Why is the oldest crust located there?
One place where the crust is the oldest is at edge of a subduction zone. It is here that the oldest ocean crust is pushed under a continental crust and destroyed. In the image below, the oldest oceanic crust is pink/purple. As you can see, the newest crust (red) is adjacent to where there is seafloor spreading.
Where are the oldest rocks found quizlet?
The earth's oldest rocks are found along the Mid-Atlantic Ridge. The theory of plate tectonics states that the earth's crust is made up of a single massive plate. The Mid-Atlantic Ridge is an example of a divergent plate boundary.
What is the asthenosphere depth?
AsthenosphereThe asthenosphere is the denser, weaker layer beneath the lithospheric mantle. It lies between about 100 kilometers (62 miles) and 410 kilometers (255 miles) beneath Earth's surface. The temperature and pressure of the asthenosphere are so high that rocks soften and partly melt, becoming semi-molten.
What is known as stratosphere?
The stratosphere is a layer of Earth's atmosphere. It is the second layer of the atmosphere as you go upward. The troposphere, the lowest layer, is right below the stratosphere. The next higher layer above the stratosphere is the mesosphere.
What is in the exosphere?
The region above about 500 km is called the exosphere. It contains mainly oxygen and hydrogen atoms, but there are so few of them that they rarely collide – they follow "ballistic" trajectories under the influence of gravity, and some of them escape right out into space.