What Are The Two Types Of Crust?

What are the 2 types of mantle?

Two parts of the upper mantle are often recognized as distinct regions in Earth’s interior: the lithosphere and the asthenosphere.

The lithosphere is the solid, outer part of the Earth, extending to a depth of about 100 kilometers (62 miles)..

What are the two parts of crust What is the basis of classification?

Earth’s crust is divided into two types: oceanic crust and continental crust. The transition zone between these two types of crust is sometimes called the Conrad discontinuity. Silicates (mostly compounds made of silicon and oxygen) are the most abundant rocks and minerals in both oceanic and continental crust.

Which crust is thicker?

Continental crustContinental crust is much thicker than oceanic crust. It is 35 kilometers (22 miles) thick on average, but it varies a lot. Continental crust is made up of many different rocks (Figure below). All three major rock types—igneous, metamorphic, and sedimentary—are found in the crust.

What is the top layer of the mantle called?

Earth’s mantleThe Earth’s mantle is a layer of silicate rock between the crust and the outer core. … The Earth’s mantle is divided into two major rheological layers: the rigid lithosphere comprising the uppermost mantle, and the more viscous asthenosphere, separated by the lithosphere-asthenosphere boundary.More items…

Is the lower mantle solid or liquid?

Lesson Summary The lower mantle is the liquid inner layer of the earth from 400 to 1,800 miles below the surface. The lower mantle has temperatures over 7,000 degrees Fahrenheit and pressures up to 1.3 million times that of the surface near the outer core.

What are earth’s layers?

Starting at the center, Earth is composed of four distinct layers. They are, from deepest to shallowest, the inner core, the outer core, the mantle and the crust. Except for the crust, no one has ever explored these layers in person.

Which of the two types of crust is denser?

There are two types of crust; oceanic and continental. Oceanic crust is denser and thinner and mainly com​posed of basalt. Continental crust is less dense, thicker, and mainly composed of granite. The mantle lies below the crust and is up to 2900 km thick.

How thick is Earth’s crust?

The crust thickness averages about 18 miles (30 kilometers) under the continents, but is only about 3 miles (5 kilometers) under the oceans. It is light and brittle and can break.

What is the physical properties of the earth’s crust?

Crust and Lithosphere Earth’s outer surface is its crust; a cold, thin, brittle outer shell made of rock. The crust is very thin, relative to the radius of the planet.

How old is the crust?

about 2.0 billion yearsThe average age of the current Earth’s continental crust has been estimated to be about 2.0 billion years. Most crustal rocks formed before 2.5 billion years ago are located in cratons.

How is crust formed?

Currently oceanic crust forms by the eruption of basaltic lava along a globe-encircling network of mid-ocean ridges. More than 18 cubic kilometers of rock are produced every year by this process. The slab of newly formed crust rides on top of an outer layer of the mantle, which together make up the rigid lithosphere.

What are 2 facts about the crust?

The crust is the thinnest layer of the Earth. It has an average thickness of about 18 miles (30km) below land, and around 6 miles (10km) below the oceans. The crust is the layer that makes up the Earth’s surface and it lies on top of a harder layer, called the mantle.

What is the basis of classification?

Basis of Classification– The characteristics based on which the living organisms can be classified. Characteristic: A distinguishing quality, trait or feature of an individual seen in all members of the same species.

Where is Earth’s crust thinnest?

PROVIDENCE, R.I. — Scientists say they have discovered the thinnest portion of the Earth’s crust — a 1-mile thick, earthquake-prone spot under theAtlantic Ocean where the American and African continents connect.

What is Earth’s thinnest layer?

crustThe crust is what you and I live on and is by far the thinnest of the layers of earth. The thickness varies depending on where you are on earth, with oceanic crust being 5-10 km and continental mountain ranges being up to 30-45 km thick.

Why is the mantle divided into 2 layers?

Explanation: The difference between these two layers of the mantle comes from the predominant mineral phases in the rock. Both the upper and lower mantle consist primarily of silicate minerals. … Asthenosphere: Most of the upper mantle is hot enough, above 1300°C, for its rock to undergo plastic flow.

What is the purpose of the crust?

The crust is a thin but important zone where dry, hot rock from the deep Earth reacts with the water and oxygen of the surface, making new kinds of minerals and rocks. It’s also where plate-tectonic activity mixes and scrambles these new rocks and injects them with chemically active fluids.