earth rocks science & minerals sedimentary & metamorphic rocks
TRANSCRIPT
Igneous RocksIgneous rock forms when hot, molten rock (melted rock) cools and hardens, becoming solid.
The melting of the rock happens deep within the Earth.
Sedimentary rock forms when layers of sediment settle on top of one another and harden over thousands, even millions of years.
Sedimentary Rock
These little bits of our earth are washed downstream where they settle to the bottom of the rivers, lakes, and oceans.
Sedimentary RockThese layers are pressed down more and more through time, until the bottom layers slowly turn into rock – Sedimentary Rock.
What is Sediment?
Sediment is made up of soil, shells, bits of rocks, and the remains of dead plants and animal matter.
Examples of Sedimentary RockFossils in the older, lower layers have older fossils.
Scientists who study the ages of rocks also study things that have lived on Earth in the past by studying fossils.
Examples of Sedimentary Rock
Mudstone is used to make cement.
Conglomerate has small gravel and pebbles.
Examples of Sedimentary Rock
Limestone can form from tiny bits of shells and skeletons of sea animals that lived long ago.
Limestone is used to make cement and glass.
Examples of Sedimentary Rock
Can find at the bottom of lakes or oceans.
Shale is made of very tiny clay particles called silt. Might contain fossils.
Metamorphic Rock
Metamorphic rockcan come from igneous, sedimentary,or metamorphicrocks.
Metamorphic rock forms heat and pressure changes how the particles of a rock are arranged forming a whole new rock.
Metamorphic RockMetamorphic means “change of form.”Heat and pressure causes the mineral crystals in the rock to change.
With heat and pressure: limestone becomes marble.
Geology for Kids
All about volcanos
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