Geology Review

Geology ReviewProcesses 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 atomsThere are more than 3,500 different kinds of minerals on Earth.

Minerals

Hardness: Mohs hardness scale: 1 to 10Streak: The colored line a mineral makes on a plate.Cleavage and fracture: How a mineral breaks.Luster: The amount of light refractionCrystal Shape: Atoms arrange in specific patterns depending on the mineralFluoresence: Glow in black lightMagnetism: A force withing some mineralsColor: Color is not the best identifying propertyMineral Properties

Rocks are made of minerals.Sheets of rock lie beneath Earths soil and water.This part of the Earth we call the crust.Most of the rocks we see are pieces that have broken off Earths 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 Earths crust called volcanoes.When lava cools it hardens into rocks.Some cools slowly and some cools quickly.Igneous Rocks

Types of Igneous Rocks

ObsidianScoriaGraniteBasaltPillow Basalt

PumiceSedimentary rocks form on Earths 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

ShaleCoquinaConglomerateBrecciaChertBauxiteMetamorphic 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

MarbleGarnetSlateRose QuartzGneissRocks 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 remainsCarbon Films

Mineral replacementMolds & 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 plateboundariesFaulting occurs whenenormous stressesBuild up and push intactrock layers beyond theirlimit.These normally happen as a result of an earthquakeEnergy traveling inside of Earths Interior

Much of whatwe know aboutEarths interiorcomes from seismic wavesBody wavestravel throughEarths interior in all directions.Scientist haveinferred that primarywaves travel through solids and liquids, but secondary waves willonly travel throughsolids.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 Earths crust through which lava, steam and ashes are expelled.Volcanoes

Geothermal energy is produced within the Earths core.Very high temperatures are continually produced inside the Earth by the slow decay of radioactive particles.Magma comes close to Earths surface by the edges of the plates where volcanoes occur.Geothermal energy is a renewable source produced deep within the Earth.

Volcanoes and Energy