• 4 months ago
Transcript
00:00Hi kids! Today we will learn about rock cycle. So let's start!
00:09Kids, we learned that there are three types of rocks.
00:14Igneous rocks, metamorphic rocks, and sedimentary rocks.
00:20Igneous rocks, lava or magma forms igneous rocks on hardening.
00:29Sedimentary rocks.
00:31The weathering of all types of rocks creates small sediments that harden into sedimentary rocks.
00:40Metamorphic.
00:42Sedimentary rocks and igneous rocks may get trapped at great depth beneath the Earth's surface under high temperature and pressure.
00:54And this extreme temperature and pressure makes the rocks undergo physical and chemical changes, which is called metamorphosis.
01:06And sedimentary and igneous rocks changes to metamorphic rocks.
01:13Now here we have the formation of different types of rocks in a cyclic manner.
01:20Let's have a look.
01:23Firstly, there is molten matter inside the Earth, which is called magma.
01:30And this magma cooling and crystallization forms intrusive igneous rocks with bigger crystals as magma cools down very slowly.
01:45And when this magma comes out of the Earth and cools down and crystallizes, it forms extrusive igneous rocks.
01:56Lava coming out of the Earth forms extrusive igneous rocks and smaller crystals that shine.
02:06The process of weathering breaks all types of rocks and creates small sediments.
02:14These sediments are carried away by the process of erosion and form layers on the beds of the rivers.
02:23And with the processes of sedimentation and compaction, these layers create sedimentary rocks.
02:34And these igneous and sedimentary rocks get trapped under high temperature and pressure.
02:42And this extreme temperature and pressure makes the rocks undergo physical and chemical changes, which is called metamorphosis.
02:55And these sedimentary and igneous rocks change to metamorphic rocks.
03:03Metamorphic rocks can be low-grade or high-grade, depending on how much they have changed.
03:12Low-grade metamorphic rocks still appear very similar to the parent rock,
03:19while high-grade metamorphic rocks have been changed so much that they look very different from the parent rock.
03:30And metamorphic rocks are melting again, form magma.
03:35Our Earth's crust constantly changes.
03:40So, three types of rocks are found on the Earth, that is, igneous rocks, sedimentary rocks, and metamorphic rocks.
03:51And all these types of rocks change to other types of rocks.
03:56And this is what we call rock cycle.
04:03Now let's revise.
04:05What is this rock cycle, and how different types of rocks change to other types of rocks?
04:12We have all the three types of rocks already present on the Earth.
04:20And upon weathering, that is, by breaking down of any rock into smaller pieces,
04:27rocks change to sediments that get settled on the beds of rivers, seas, and oceans.
04:35And ultimately change to sedimentary rocks by the process of compaction and cementation.
04:46And every type of rock, whether it is igneous or sedimentary or metamorphic,
04:54when trapped beneath the Earth's surface at a great depth,
04:58experiences great pressure and temperature that change it to metamorphic rocks by the process of metamorphosis.
05:08So, till now we have learned that weathering changes rocks into small sediments that changes into sedimentary rocks.
05:20And every type of rock, whether it is igneous or sedimentary or metamorphic,
05:27when trapped beneath the Earth's surface at a great depth, experiences great pressure and temperature.
05:34And this process and temperature starts the process of metamorphosis in the rocks
05:41that changes the types of rocks to metamorphic rocks.
05:47Now let's learn how igneous and sedimentary or metamorphic rocks get changed into lava or magma.
05:57If any type of rock experiences very high temperature and pressure,
06:03it gets changed into magma.
06:06That is, it gets melted down to magma.
06:11And we know that magma changes to two types of igneous rocks.
06:16It can be intrusive igneous rocks and extrusive igneous rocks.
06:23And there is continuous transformation from one type of rock to another type of rock.
06:30And this is called rock cycle.
06:34So kids, today we learned what is rock cycle.
06:39Now you may go ahead and take a quiz to learn more.
06:43Bye-bye!