2What Are Rocks?Rocks are a mixture of one or more minerals as well as mineraloids, glass or organic particlesOften several different minerals are mixed together, which gives a rock its color and texture.Often these minerals, mineraloids, glass or organic particles must be put under great pressure or heat.
3There Are Three Different Types of Rocks Igneous Rock2. Metamorphic Rock3. Sedimentary Rock
5Igneous rocks are rocks that are formed as molten material cools. They can form underground where magma cools slowly or above ground where lava cools quickly.
6There Are Two Types Of Igneous Rock Intrusive Igneous Rock2. Extrusive Igneous Rock
7Intrusive Igneous Rock Intrusive igneous rocks are rocks that are formed when magma cools beneath Earth’s surface.They are found when the rocks and soil that once covered them are removed by erosion.They are also found when forces like compression or tension push molten material to Earth’s surface.
8Extrusive Igneous Rock Extrusive igneous rocks are formed by lava that cools on Earth’s surface.The lava is exposed to air and moisture, and it cools quickly.Which igneous rock will have bigger crystals?
9Classifying Igneous Rocks Unless you’re near an erupting volcano, we can’t witness the formation of igneous rocks. So how do we know if the igneous rock is intrusive or extrusive?
10Look at the size of the crystals in the rock. If it has big crystals it means it cooled slowlyIf it has small crystals it means it cooled quicklyThis piece of ryholite cooled quickly on the surface, it has small crystals.This piece of granite cooled slowly below the surface, it has big crystals.
11Ways to Define Grain Size There are certain words used to describe the grain size in a rock. Some of the words are:Fine-grainedCoarse-grainedGlassyPorous
12Igneous rocks can also be grouped by their overall color. Light colored rocks must be composed of light colored minerals like quartz or feldspars.Dark colored rocks are composed of minerals like pyroxenes and amphibolesQuartzPyroxenes
13A Little More About Igneous Rocks These rocks are the most abundant type of rocks on Earth. They’ve been classified to make them easier to study. By studying them geologists and other scientists have been able to hypothesize how Earth formed. Kinda big deal? Yeah I think so.
14Metamorphic RocksSo you found a rock on the way to school, because you know so much about igneous rocks you are able to classify this as one. Will this rock remain unchanged forever?Can you think of some ways that rocks can change?
15Ways That Rocks Change There are different methods that rocks change. WeatheringHeatPressureAs well as the otherLets talk about lunch
16What Are Metamorphic Rocks? Metamorphic rocks are rocks that are changed by heat or pressure or both.
18BasicallyRocks under Earth’s surface are put under pressure from the layers above and they are exposed to heat from magma.If these are great enough, the rocks melt and magma forms.If these are not great enough to melt the rocks, mineral grains in the rock may change in size or shape.
19This picture is of pebbles that look like normal ones from the front but going to a right hand cut angle the pebbles are longer than expected. This is caused by the pebbles stretching during metamorphism, it became hot enough to behave like plastic and stretch.This is a picture of quartz grains that were probably originally rounded but have been recrystallized under high pressure and temperatures to which caused the grains to grow larger and infringed on each other.
20Classifying Metamorphic Rocks Metamorphic rocks that have a foliated texture form when minerals in the original rock flatten under pressureFoliated- texture of metamorphic rocks whos mineral grains have been flattened and lined up in parallel bands
21Examples of Foliated Rocks Some examples of foliated rocks include slate which forms from shale.
22Some metamorphic rocks the mineral grains change, combine, and rearrange, but do not form visible bands. This is known as non-foliated texture
23Difference Between Foliated and Non-foliated Foliated rocks will break easily into layers.Non-foliated rocks will fracture into pieces of random sizes and shapes.
24Sedimentary Rocks Where do sedimentary rocks come from? What are the two major processes that change Earth’s surface?WeatheringErosion
25Weathering of RocksThe weathering of rocks is when rocks or remains of plants and animals are broken down into smaller pieces called sediments
26Erosion of RocksWhen rocks are transported by water, wind, ice and gravity.Once they are transported they are deposited somewhere, or dropped off.This rock, Siwash Rock, was once apart of Stanley Park but became separated through the process of erosion and weathering.
27What are Sedimentary Rocks? Under certain conditions deposited sediments recombine to form a solid rock.
28How do Sedimentary Rocks form? Layer after layer sediments are deposited. As more and more layers form, the pressure they apply to the layers beneath them causes the sediments to compress.This is called compaction.
30Classifying Sedimentary Rocks Sedimentary rocks can be composed of any type of weathered and eroded rock material and sometimes even particles from plants and animals.To classify these rocks we must look at the sediment they contain and the way that the rock was formed.
32Detrital Sedimentary Rocks These rocks are made of broke fragments of other rocks.The fragments have been compacted and cemented together.
33ShaleShale is a detrital sedimentary rock. It requires little cementation to hold its particles together. The sediments are clay-sized minerals which are even smaller than sand-sized particles. These sediments can compact together by pressure from overlying layers.Can you think of another detrital sedimentary rock?
35The sediments from detrital rocks come from weather and are transported as solid particles. Does this happen with all sedimentary rocks?LimestoneRock Salt or Halite
36Chemical Sedimentary Rocks Some sedimentary rocks come from minerals that were once chemical compounds dissolved in solution.So if these minerals are in solution form how can we get them to be in sedimentary form?Evaporation
37Chemical Sedimentary Rocks When the water in lakes and seas evaporates they leave behind the chemical compound in concentrated amounts.What are some of the rocks that can form from this task?Gypsum, rock salt, and limestone are some of the chemical sedimentary rocks!
38Organic Sedimentary Rocks What are the materials that sedimentary rocks form from?Fragments of other rocksChemical compoundsMineralsFOSSILS!!!
39Organic Sedimentary Rocks Organic sedimentary rocks have large amounts of remains known as fossils.What are fossils?These rocks are classified as organicsedimentary rocks.- One of the most common is limestone which consists mostly of the remains of once living aquatic organisms.
40Organic Sedimentary Rocks Ocean animals like mussels and snails make their shells from calcite and other minerals. When they die their shells accumulate on the ocean floor where they can be compacted together and form sedimentary rocks.
41Rock CycleThe process by which Earth’s materials change to form different kinds of rocks makes up different kinds of rocks.
43Rock Jokes What does a rock want to be when it grows up? A rock starWhat do you do to a baby rock?--Rock itWhat do you call a dog who collects rocks?A RockhoundHow do rocks wash their clothes?In the Rock Cycle