Download presentation
Presentation is loading. Please wait.
1
Rock Cycle How do rocks form?
2
Chapter 4:Rocks: Mineral Mixtures
Section 1: The Rock Cycle Section 2: Igneous Rock Section 3: Sedimentary Rock Section 4: Metamorphic Rock
3
Rock Cycle A rock is a naturally occurring solid mixture of
one or more minerals.
4
Weathering, Erosion, and Deposition
Weathering is the breaking down or dissolving of rocks and minerals on the Earth’s surface. Water, ice, acids, salt, plants, animals, and changes in temperature are all agents of weathering.
5
Education National Geographic on Weathering
6
Erosion When water, wind, ice, or gravity move sediments over the Earth’s surface, this is called erosion.
7
Deposition: Deposition is when sediments stops moving and is deposited.
8
ROCK CYCLE
9
Rock Cycle
10
Rock Cycle
11
Igneous Rock
12
Igneous Rock Igneous rock is formed from lava or magma.
Magma is hot, melted rock inside the Earth. (1300 to degrees Fahrenheit or 700 to 1,250 degrees Celsius) Lava is magma that has erupted from a volcano.
13
3 Ways that Magma Forms 1. Increase in temperature
2. Decrease in Pressure 3. Addition of Fluids
14
Classification of Igneous Rock
1. Composition 2. Texture
15
Classification of Igneous Rock: Composition
Felsic Rock Elements – sodium, potassium, and aluminum Most felsic rocks are light color e.g. granite, rhyolite Mafic Rock Elements – iron, calcium, and magnesium Most mafic igneous rocks are dark colored. e.g. basalt and gabbro
16
How are basalt and gabbro different
For more in formation, read this article to see why they are different.
17
Classification of Igneous Rock: Texture
The texture depends on the size of grains in the rock. The texture of igneous rocks depends on fast the magma cools. Intrusive Igneous Rock Extrusive I gneous Rock
18
Intrusive verses Extrusive
Intrusive – inside Earth’s surface Extrusive- Outside Earth’s surface The magma cools slowly below the Earth’s surface. Magma is called lava when it reaches the Earth’s surface. Extrusive igneous rock forms when lava cools, which is quicker on the surface of the Earth.
19
Rock Cycle
20
Sedimentary Rock Sedimentary is formed by compaction and/or cementation. When new layers sand, dirt, mud, and pebbles are deposited on top of older layers, the weight causes the grains to squish together tightly. This is compaction. Cementation happens when the grains stick together like the cement walkways outside this building. Go to or for more information.
21
Strata and Stratification
Sedimentary rocks are formed in layers. The formal term for layers is strata (or stratum for short). Stratification means the act of making strata or layers. Go to for more information.
22
Rock Cycle
23
Metamorphic Rock Metamorphic rock forms when the chemical composition of a rock changes because of heat and pressure.
24
Rock Cycle Interactive Activity
Go to this web site. Try it out.
25
Rocks I hope you have a better understanding of the rock cycle.
Powerpoint created by Sallie Muckenfuss Salazar
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.