Rocks Flashcards
What are the three main components of Earth
Lithosphere
hydrosphere
atmosphere
What is biosphere
Biosphere is the area/region in which all the three main components of Earth interact meet and overlap
This is the zone in which most living creatures exist
Types of forces on the earth surface
Internal and external
What do external forces do
They smoothen the landforms on the earth surface
example-
wind and running water
What do internal forces do
they originate under the Earth’s surface
They are related to the volcanoes and earthquakes
What are rocks
Rocks are aggregates of minerals with no definite chemical composition
They form most of the solid material in the lithosphere
What is a mineral
Minerals are the raw materials of rocks
They have a definite chemical composition, chemical properties and physical properties
Example-
Silicates and quartz
Rocks that contain metals in large quantities are known as
Ores
Importance of rocks
Rocks are used for building material
They supply raw materials for manufacturing industries
They supply precious metals such as gold and silver
On disintegration they form smaller particles which are known as soil
Types of rocks
Igneous
metamorphic
sedimentary
Other name for igneous rocks
Parent rocks
Primary rock
How are igneous rocks formed
Igneous rocks are formed when molten magma produced from a volcano solidifies and crystallizes inside the Earth or on the Earth’s surface
Why are igneous rocks called parent rocks
Igneous rocks make up 85% of the earth’s crust
They help in the formation of sedimentary rocks
Types of igneous rocks
Intrusive igneous rocks
Extrusive igneous rocks
Example of intrusive igneous rock
Granite and gabbro
Example of extrusive igneous rocks
Basalt and Pumice
Characteristics of igneous rocks
Igneous rocks are granular and crystalline They are hard and compact They are non fossiliferous They do not wear out easily They do not have layers
Uses of igneous rocks
Jewellery making-obsidian
flooring and kitchen worktop- granite
Used as concrete- basalt
What are intrusive igneous rocks
Igneous rocks the Magma that solidify is under great pressure inside the earth
What are extrusive igneous rocks
Extrusive igneous rocks are igneous rocks that get formed on the Earth’s surface when Magma rapidly cools and solidifies
What are sedimentary rocks
sedimentary rocks are rocks that are formed when the waste products of the older rocks get broken down by agents of denudation such as wind running water and glacier
They are found in lakes and oceans
They are formed in layers or strata
Types of sedimentary rocks
Mechanically formed-sandstone shale and clay
Chemically formed - rock salt and gypsum
organically formed - coal and petroleum
Characteristics of sedimentary rocks
They are in layers
they contain fossils
they are not crystalline and not very hard
they are permeable rocks
