Geology Review

Processes of Rock and Soil Formation

Minerals are substances found in nature. Minerals are solid. Minerals are inorganic. Minerals are made of atoms. Some minerals are made of only one kind of

mineral. Most are made of different types of atoms There are more than 3,500 different kinds of

minerals on Earth.

Minerals

Hardness: Moh’s hardness scale: 1 to 10 Streak: The colored line a mineral makes on a

plate. Cleavage and fracture: How a mineral breaks. Luster: The amount of light refraction Crystal Shape: Atoms arrange in specific

patterns depending on the mineral Fluoresence: Glow in black light Magnetism: A force withing some minerals Color: Color is not the best identifying property

Mineral Properties

Rocks are made of minerals. Sheets of rock lie beneath Earth’s soil and

water. This part of the Earth we call the crust. Most of the rocks we see are pieces that have

broken off Earth’s crust.

Rocks

Igneous rocks are made deep inside Earth. These rocks are made from magma. Magma is melted rock deep inside Earth. When magma cools, it becomes solid rock. Sometimes magma flows out of holes in

Earth’s crust called volcanoes. When lava cools it hardens into rocks. Some cools slowly and some cools quickly.

Igneous Rocks

Types of Igneous Rocks

Obsidian

Scoria

Granite

Basalt Pillow Basalt Pumice

Sedimentary rocks form on Earth’s surface of

just beneath it. They are made of small pieces called

sediments. Sediments can be mud, sand, stones, shells or

bone. When sediments harden together, they

become sedimentary rock.

Sedimentary Rocks

Types of Sedimentary Rock

ShaleCoquina

Conglomerate

BrecciaChert

Bauxite

Metamorphic rocks are made out of other

kinds of rock. Heating and squeezing change the minerals

inside the rock and they become metamorphic.

Rocks are pushed and squeezed inside Earth. Sometimes the tectonic plates push against

one another forcing the rocks to be squeezed together.

Metamorphic Rock

Metamorphic rocks

MarbleGarnet

SlateRose Quartz

Gneiss

Rocks are part of a cycle, or pattern, that happens again and again.

The rock cycle changes old rocks into new ones.

Water, wind and ice change rocks. Heat changes rocks. Movement can push rocks inside Earth.

Rock Cycle

Forces within the Cycle

Erosion is response to changes in rock over

time. Rocks can be eroded by water, wind and ice.

EROSION

Weathering is the process that decomposes or

breaks down exposed rock. One type is chemical

Another type is mechanical

Weathering

Bridges and arches form when rocks have

been weathered and eroded.

Weathering Formations

Fossils are the hardened remains of plants

and animals. Fossils are also the traces and remain of

plants and animals that lived more than 10,000 years ago.

Fossils

Preserved remains Carbon Films

Mineral replacement Molds & casts

Fossil Types

Fossils are plant and animal remains that have

been naturally preserved. Most remains disappear over time. Fossils that remain usually get buried and the

remains are protected. They are hidden from animals and are safe

from water and wind.

Preserved Fossils

Deposition is when sediments that are carried

are deposited. It is because of deposition that many fossils

are preserved.

Deposition

This is a way of finding the relative order of

past events without determining their absolute age.

Fossils are often used to correlate on stratigraphic column with another.

Relative Age

Folding and Faulting

Folding occurs when rock is compressed

asit is along colliding

plateboundaries

Faulting occurs whenenormous stresses

Build up and push intactrock layers beyond their

limit.

These normally happen as a result of an earthquake

Energy traveling inside of Earth’s

InteriorMuch of what

we know aboutEarth’s interior

comes from seismic waves

Body wavestravel through

Earth’s interior in all directions.

Scientist haveinferred that primarywaves travel through solids and liquids, but secondary waves willonly travel through

solids.

An earthquake is what happens when two

blocks of Earth suddenly slip past each other. Where they slip is called the fault. The location directly above it on the surface of

the Earth is called the epicenter.

Earthquakes

The Earth has its own internal heat source that

provides energy for our dynamic planet.

A volcano is a vent in Earth’s crust through which lava, steam and ashes are expelled.

Volcanoes

Geothermal energy is produced within the

Earth’s core. Very high temperatures are continually

produced inside the Earth by the slow decay of radioactive particles.

Magma comes close to Earth’s surface by the edges of the plates where volcanoes occur.

Geothermal energy is a renewable source produced deep within the Earth.

Volcanoes and Energy