Magma
The molten mixture of rock-forming substances, gases, and water from the mantle.
Lava
Liquid magma that reaches the Earth's surface
Weathering
The chemical and physical processes that break down rock at the Earth's surface.
Erosion
The process by which water, wind, or gravity moves fragments of rock and soil
Deposition
The process by which sediments settle out of the water or wind that is carrying it, and is laid down in a new location
Sediment
Small, solid particles of materials from rocks or organisms which are moved by water or wind, resulting in erosion or deposition
Rock cycle
Set of natural processes that form, change, break down, and re-form rocks
How long does it take for rocks to change into different kinds of rocks?
Usually over a huge span of time: thousands to millions of years
Does the rock cycle have a beginning or end?
It has no beginning or ending but goes on continually; allows rocks to change from one form to another
How are igneous rocks formed?
Forms when molten rock cools and becomes solid.
Where can igneous rocks form?
Form on the surface of the Earth (extrusive) and on the inside of the Earth (intrusive)
How are sedimentary rocks formed?
Forms when pieces of older rocks, plants, and other loose material get pressed or cemented together
Where are older and younger layers of sediment located?
younger layers are found toward (or on) the surface of the Earth and older are found toward (or at) the bottom of the rock
Metamorphic rocks formation
This type of rock forms when heat or pressure cause older rocks (igneous or sedimentary) to change into new types of rocks.
Metamorphic rocks are located
These rocks can be found inside the Earth and/or raised to Earth's surface over time.
The layers of the Earth
inner core, outer core, mantle, crust
inner core
ball of hot, solid metals at the center of the Earth
Metals found in the inner core
Iron and nickel
How Earth's core be solid AND hot at the same time.
There is enormous pressure at the center of Earth. This squeezes the atoms of the metals so closely together that the core remains solid despite the intense heat
Pressure, temperature, and density change as move from the crust to the core.
It increases as you move from the crust to the core
Temperature, pressure, density change as move from the core to the crust.
It decreases as you move from the core to the crust
outer core
A layer of liquid metals that surrounds the inner core
Why the outer core is liquid.
The lower pressure allows the metals to remain liquid
Mantle
Earth's thickest layer, made of hot rock that is less dense than the metallic core
Describe the top part of the mantle and the region just below it.
The very top part of the mantle is cool and rigid. Just below that, the rock is hot and soft enough to move like a thick paste.
crust
Thinnest layer of the Earth. Made of cool rock
Two basic types of crust.
oceanic crust and continental crust
continental crust
Includes all continents and some major islands
oceanic crust
Includes all the ocean floors
Where the Earth's crust the thinnest.
Under the oceans (oceanic crust)
Where the Earth's crust the thickest.
Under continental mountain ranges (continental crust)
lithosphere
Earth's crust and the very top of the mantle
Most rigid of all the layers *Sits on top of the asthenosphere
asthenosphere
*Layer of hotter, softer rock in the upper mantle.
*Soft enough to flow slowly like hot tar
tectonic plates
Many broken large and small slabs of rock (lithosphere)
The crust make up most tectonic plates.
Continental crust (rises above the ocean) and oceanic crust (ocean floor)
Description of Earth 4.6 billion years ago.
Earth was a spinning mass of rocks and dust loosely held together.
Events over time to change the Earth to change the Earth's mass and turn it into a glowing ball of rock.
Many comets and asteroids crashed into its surface and added to its mass. These impacts, along with radioactive decay and Earth's gravity, produced intense heat. The young planet became a glowing ball of melted rock.
Where materials with greater density ended up. Give 2 examples of these denser materials.
Denser materials, such as iron and nickel, sank toward the center of Earth.
Where less dense materials that make up the Earth eventually ended up.
Less dense materials moved toward the surface.
Where materials that were not the most dense nor the least dense ended up during the formation of the Earth.
-Other materials settled between the planet's center and its surface.
-Slowly, Earth's main layers formed�the core, the mantle, and the crust
Pangaea
name of the super continent that existed 200 million years ago, the name means "all land
continental drift
the hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations
seafloor spreading
Hess's theory that new seafloor is formed when magma is forced upward toward the surface at a mid-ocean ridge, forcing the plates away from each other
convection current
the movement of a fluid, caused by differences in temperature and density, that transfers heat from one part of the fluid to another