00:00So students, I am going to tell you the basic definitions of sedimentary rock and igneous rock.
00:08The third one is metamorphic rock.
00:12Metamorphic rock, as you can see, the word that we have here,
00:16it means metamorphism.
00:18It means to change.
00:20To change.
00:22It means that this rock is formed due to the change of igneous and sedimentary rocks.
00:28The condition of the sedimentary rock is not the same as that of the igneous rock.
00:32Instead, a new rock has been formed.
00:33We call it metamorphic rock.
00:35Basically, either the metamorphic rock is of igneous or sedimentary rock.
00:38But its new characteristics and properties do not match with either igneous rock or sedimentary rock.
00:43That is why we call it metamorphic rock.
00:46There are two processes of metamorphic rock.
00:48One is thermal metamorphism.
00:59Thermal metamorphism.
01:01And the second one is contact metamorphism.
01:09Thermal metamorphism is the process of modifying the source of heat.
01:14Temperature.
01:15Heat.
01:16It means that the surface of the earth is being directed by a volcano.
01:20And the magma is in its way towards the surface of the earth in any specific direction.
01:26So, during the journey, when the magma crosses this area,
01:29and if there is an igneous or sedimentary rock present there,
01:31then due to its heat, the rocks on the sides burn or change their properties.
01:36So, for example, if we have a granite rock there,
01:42then magma passes near the granite rock.
01:45Due to its heat, the granite changes its properties and changes in the genesis.
01:49So, genesis is a metamorphic rock.
01:51Similarly, in the second case, contact metamorphism.
01:54In this, the pressure of the tectonic plates develops.
02:01That's why it happens that when our plate is tectonic,
02:04when it moves due to any reason,
02:06specifically, you can say that the energy stored in the plates,
02:10there is a method to release that energy.
02:12So, when it is released, the plates move.
02:14So, due to the movement, the area where the plates are lying,
02:18due to their pressure, the rocks that are already present there,
02:21or if there is an igneous or sedimentary rock present there,
02:23they change their properties.
02:25Due to intense pressure.
02:27So, due to this, a new rock is being formed.
02:29It is neither igneous nor sedimentary,
02:31but it is a metamorphic rock due to contact metamorphism.
02:33Now, if you want to take an example of this,
02:35then we have slate.
02:37Slate is a metamorphic rock,
02:39which is a clay or sandstone.
02:41Due to its metamorphism, due to the pressure of the tectonic plate,
02:45due to the pressure, the sandstone or mud clay
02:48gets converted into the slate.
02:50Is it clear, student?
02:51So, this was the contact metamorphism.
02:53So, student, we have done an overview in general
02:55about rocks and their types.
02:57So, I will brief you a little.
02:59We have defined the rock.
03:00Rock is a natural substance.
03:02It is an organic origin.
03:04It is a part of our planet.
03:06In the opposite, we have seen the mineral.
03:08We have a unique combination of chemical and physical properties.
03:12Its structure is unique.
03:14There are two or more minerals in a rock.
03:17So, the difference is also that the mineral is of rock.
03:19We have defined it.
03:20Then we talked about the types.
03:21Basically, sedimentary, igneous, and metamorphic.
03:24We have three types of rocks.
03:25We have defined those rocks separately.
03:27There are 21 types of rocks,
03:28which are formed by cooling and solidification of magma or lava.
03:32Their further types are protonic rocks,
03:34i.e., 2C rocks, 2C rocks, and hyperbosal rocks.
03:37In their example, we have basalt.
03:39Lava basalt is an important example.
03:40Similarly, the right one is obsidian.
03:42Obsidian is an igneous rock.
03:44In ancient times, obsidian was used to kill animals, to make tools.
03:51So, obsidian was used as a cutting tool.
03:55Similarly, we have granite and pumice.
03:59You must have heard about pumice.
04:01It is a rock that floats on water.
04:03It is well-known that pumice floats on water.
04:07The second type is sedimentary rock.
04:11We have defined three types of sedimentary rocks.
04:13They are mechanical-formed sedimentary rocks,
04:15chemically-formed sedimentary rocks,
04:16and organic-formed sedimentary rocks.
04:18There are many types of these rocks.
04:19We have a lot of sedimentary rocks in our surface.
04:23For example, we have china clay, muddy clay, chalk,
04:26coal, rock salt, and chypsum.
04:28We have many examples of these rocks.
04:30The third type is metamorphic rocks.
04:32We have defined metamorphic rocks to change igneous and sedimentary rocks into metamorphic rocks.
04:37We have defined metamorphic rocks to change igneous and sedimentary rocks into metamorphic rocks.
04:41There are many types of these rocks.
04:43For example, we have the genesis rock, which is in the form of granite.
04:46Similarly, we have the slate rock, which is in the form of clay.
04:53Similarly, we have the marble rock.
04:55Taj Mahal is made up of marble.
04:58Marble is also a metamorphic rock.
05:00Basically, it is made up of limestone.
05:02It is a thermal metamorphic rock.
05:04Okay students, this is our lecture about rocks and their types.
05:08Hopefully, you have understood this.
05:10If you have any questions, you can ask them.
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