Introduction to Rocks
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Transcript of Introduction to Rocks
INTRODUCTION TO ROCKS
Geology Unit 2
What are Rocks?
Rocks are simply aggregates (combinations) of one or more minerals.
Rocks can be hard or soft, vary in size. Integral part of human history
First tools were made of stone Shelter Monuments, etc.
The study of rocks is the science of petrology.
Rock system of classification There are many types of rocks,
geologists classify rocks based on HOW the rocks were formed.
There are three categories of rocks: 1. Igneous 2. Sedimentary 3. Metamorphic
Igneous Rock
How do they form? Forms directly from liquid rock (magma). Liquid rock cools and hardens to form
Igneous rock. Liquid rock inside the earth is Molten magma Liquid rock that exits onto the earth’s surface is
known as lava.
Examples of Igneous Rock
Source: http://www.geog.ucsb.edu/~dylan/mtpe/geosphere/topics/rx/igneous.html
Sedimentary Rock
Result from pre-existing rock Sedimentary Rock = layered rock.
Rocks break down into pieces due to environmental forces (wind, water, ice)….more on this later
Pressure (due to weight of sediments) solidify these rock particles together. This happens continuously, forming layered rock.
Examples of Sedimentary Rock Gros Morne National Park, Newfoundland
Examples of Sedimentary Rock Parrsboro,
Nova Scotia
Examples of Sedimentary Rock… Hopewell Rocks, NB
Examples of Sedimentary Rock..
Source: http://www.geog.ucsb.edu/~dylan/mtpe/geosphere/topics/rx/sedimentary.html
Metamorphic Rock
Form from pre-existing igneous & sedimentary rocks
High temperatures & pressure cause the pre-existing rock to become physically or chemically altered. Pre-existing rock becomes warped,
deformed, compressed/compacted into a smaller volume of space. They become more dense Metamorphic rocks are less susceptible to
erosion.
Examples of Metamorphic Rock…
Source: http://www.geog.ucsb.edu/~dylan/mtpe/geosphere/topics/rx/metamorphic.html
Your Task
Become familiar with the three types of rocks, their characteristics and how we can identify them.
How? by completing worksheets and visiting my website. Igneous Rocks Sedimentary Rocks Metamorphic Rocks