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