Types of Rocks

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Shri Chhatrapati Shikshan and Arogya Prasark Mandal’s,
Shri Sant Gajanan Mahavidyalaya, Kharda
Tal. Jamkhed, Dist. Ahmednagar
DEPARTMENT OF GEOGRAPHY
Class: FYBA Element of Geomorphology
Mr. S.T. JADHAV M.A; NET (Geog)
Types of Rocks
Types of Rocks
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Types of Rocks
There are 3 types of
rocks found on Earth:
• Igneous
• Sedimentary
• Metamorphic
Knowing the differences
between these 3 types of
rocks allows us to learn
about Earth’s past.
Igneous Rocks
Igneous Rocks are formed by melting, cooling, and crystallization of other
rocks.
Igneous rocks form as a result of volcanic activity, hot spots, and melting
that occurs in the mantle.
Igneous rocks are common along plate boundaries or mantle hot spots
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Types of Igneous Rocks
The most common types of igneous rocks include:
Rhyolite
Andesite
Basalt
Granite
Diorite
Gabbro
Sedimentary Rocks
Sedimentary rocks are formed by weathering, erosion,
deposition, compaction, and cementation of other rocks.
Sedimentary rocks form in areas where water, wind, or gravity
deposit sediments.
Sedimentary rocks are likely to form in areas such as:
Deltas
Beaches
Rivers
Glaciers
Sand dunes
Shallow seas
Deep oceans
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Structures and formations seen in sedimentary rocks
include:
Stratification
Cross bedding
Graded bedding
Ripple marks
Mud cracks
Fossils
Types Sedimentary rocks
Some of the most common types of sedimentary rocks include:
• Conglomerate
• Sandstone
• Shale
• Limestone
• Gypsum
• Oolites
• Chert
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Metamorphic rocks
Metamorphic rocks are formed by heat and pressure changing one type of
rock into another type of rock.
Metamorphic rocks form near lava intrusions, at plate subduction zones,
and in deep mountain roots.
Lava intrusions can provide heat that causes metamorphic rocks to form.
These small areas of metamorphic rock form from contact
metamorphosis.
Some common types of metamorphic rock include:
 Slate
 Schist
 Gneiss
 Amphibolite
 Marble
 Quartzite
 Metaconglomerate
Types Metamorphic rocks
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