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