CHAPTER-2 INSIDE OUR EARTH PRESENTED BY Dr. SWASTI SINHA
ABOUT MYSELF . Dr. Swasti Sinha . B.D.S. ESIC Dental College Delhi . Avid reader . Art and Craft Enthusiast . Unacademy Educator since 2017
Crust Mantle Outer Core Inner Core
Lithosphere (crust and upper- most solid mantle) Crust 0-100 km thick Asthenosphere Mantle Crust Mantle 2900 km Liquid Outer core Core 5100 km Inner core Solid Not to scale 6378 km To scale
CRUST Uppermost layer * Thinnest 35km on the continents and only 5km on ocean floors . Sial-> main minerals on the continental crust . Sima-> main minerals on the oceanic crust
MANTLE Depth of 2900 km below crust
CORE Radius of 3500km * Innermost layer Made of NiFe . Very high temperature and pressure Deepest mine is in South Africa (4km Deep)
Continental Crust Sedimentary Deposits Oceanic Crust 10 km 100 km Lithosphere Plastic Asthenosphere 200 km Upper Mantle (down to 670 km)
crust forms only 0.5% volume ofthe earth 16% consists of the mantle and 83% makes the core Radius of earth is 6371km
ROCKS AND MINERALS ROCK-> Any natural mass of mineral matter that makes up the earth's crust is called a rock. Different types: 1. lgneous 2. Sedimentary 3. Metamorphic rocks
IGNEOUS ROCKS . Formed by the solidification of molten magma Primary rocks . Two types> intrusive and extrusive. * Igneous-Latin word meaning fire.
Extrusive lgneous Rock (Magma comes out as lava and cools on the surface) Intrus ive Igneous Rock (Magma cools off beneath the surface ) Earth's surface Magma
METAMORPHIC ROCKS . Under great heat and pressure the igneous and sedimentary rocks change into metamorphic rocks, Example-clay changes into slate and limestone into marble.
3. Metamorphic Rocks Pressure vetomorhiG ROk 0
USES OF ROCKS Hard rocks-> roads, houses, buildings Games like seven stones etc. . Red Fort is made up of Red Sandstone and Taj Mahal is made up of White Marble.
THE ROCK CYCLE Sedimentary Rock Metamorphic Rock Changed by Hoat Pressure andlor Chemical Action Igneous Rock Magma Martie