1. SOLID EARTH Prepared by Pat Davis, Science Teacher,
Durham Middle School, Lewisville ISD

2. The Science of Geology
Geology is the study of planet Earth, including Earth’s surface and interior.
Geologists study the physical and chemical characteristics of minerals and rocks, plus the processes that have shaped Earth.
Geologists study physical conditions, such as temperature and pressure, inside Earth. Geologists also study the forces inside Earth that affect the surface.

3. Inside Earth
Rock is the material that makes up Earth’s hard outer surface.
A layer of solid rock called the crust surrounds Earth’s surface like the tough shell of a walnut.

4. Rocks and the Rock Cycle
Rock forms Earth’s crust.
Rock is a solid material made up of one or more minerals or other substances, including the remains of once-living things.
Most of Earth’s rocks are made up of about 20 common minerals
Called rock-forming minerals.

5. Igneous Sedimentary Metamorphic Classifying Rocks How they are formed:
Three ways:
Igneous
Sedimentary
Metamorphic

6. Igneous Rock forms when magma or lava cools and hardens
Magma rises through cracks in rock deep beneath the surface.
Cools very slowly
Geologists classify igneous rocks according to whether the rocks formed above or beneath Earth’s surface
intrusive rock – formed beneath the surface
granite
extrusive rock – formed above the surface
basalt
Basalt
Granite
Two common igneous rocks are basalt and granite. Basalt is a dark, extrusive rock that makes up much of the oceanic crust. Granite is a light-colored intrusive rock that is common in continental crust.

7. Igneous Rocks: Granite

8. Sedimentary Rock
forms when particles of rock and other materials are pressed and stuck together.
sediment --- particles of rock or material from living things.
sand and gravel on a beach and the mud on a riverbank are sediments.
All of these can make sedimentary rock.
erosion moves sediment from place to place
sediment is laid down in a process called deposition.

9. Horizontal Beds of Sedimentary Rock
Source: William E. Ferguson

10. How Sedimentary Rock is Formed
Layers of sediment build up
Weight of the layers above presses down
Compaction, squeezes the layers
Cementation, glues the sediment together
Occurs when water dissolves some of the sediment
Compaction and cementation may continue for millions of years.
The sediment changes to sedimentary rock
Sedimentary rocks form through the erosion, deposition, compaction, and cementation of sediments. (A) Water or wind deposits sediment. (B) The heavy sediments press down on the layers beneath. (C) Dissolved minerals flow between the particles and cement them together.

11. Metamorphic Rock
Created by heat and great pressure deep beneath Earth’s surface.
Sometimes, heat from a volcano.
Any kind of rock can become a metamorphic rock
Heat and pressure can change any rock into metamorphic rock. For example, granite becomes gneiss, and sandstone changes to quartzite.

12. Types of Rocks Sedimentary Igneous Metamorphic NAME (Examples) CAUSE
LOCATION
CHARACTERISTICS
Sedimentary
limestone; sandstone; chalk; coal; rock salt; shale; dolomite; conglomerate
created when layers of sediment (mud, sand, gravel and minerals) settle to the bottom of the ocean and then compacted (pressed together) over thousands of years
where oceans or bodies of water once existed or still exist
soft, layered, may contain fossils
Igneous
quartz; pumice; granite; basalt; obsidian
created when molten rock (lava) inside the Earth pushes through the crust (like in a volcanic eruption) and then cools
where volcanoes have or do exist
crystalline, glossy, coarse-grained
Metamorphic
marble; slate; gneiss; schist; quartzite; eclogite
created when sedimentary or igneous rocks undergo metamorphosis (change) caused by pressure, heat, and water acting on the rocks
deep within the earth (where pressure and heat have a very large affect)
hard, may contain bands or layers, may contain crystals

13. Forces inside Earth and at the surface produce a rock cycle that builds, destroys, and changes the rocks in the crust.
rock cycle is a series of processes on and beneath Earth’s surface that slowly change rocks from one kind to another.
The Rock Cycle

14. The Rock Cycle
Igneous, sedimentary, and metamorphic rocks change continuously through the rock cycle.

15. Key Ideas
Geologists study Earth and the processes that have shaped Earth over time. They study the minerals and rocks that make up Earth, physical conditions inside Earth, and the forces inside Earth that affect the surface.

16. Key Ideas
The three major groups of rocks are igneous, sedimentary, and metamorphic.
The series of processes on and beneath Earth’s surface that change rocks from one type to another is called the rock cycle.
Rocks can be formed when magma or lava hardens, when sediments are cemented and compacted together, or when heat and pressure change rock deep beneath Earth’s surface.