Rocks What are they?
The Rock Cycle 4/15/15 Key Question: What are rocks and where do rocks come from? Initial Thoughts:
Evidence #1 What is a rock? A rock is a mixture of minerals, rock fragments, volcanic glass, organic matter, or other natural materials. Most rock used for building stone contains one or more common minerals, called rock-forming minerals, such as quartz, feldspar, mica, or calcite When you look closely, the sparkles you see are individual crystals of minerals.
Rock Types Igneous Sedimentary Metamorphic There are three types of rocks Igneous Sedimentary Metamorphic
What is the rock cycle? To show how rocks slowly change through time, scientists have created a model called the rock cycle. It illustrates the processes that create and change rocks.
Rock Cycle Continued The rock cycle shows the three types of rock— igneous, metamorphic, and sedimentary—and the processes that form them.
The Rock Cycle explains how Rocks and Natural Processes are related weathering Sedimentary Metamorphic Is the rock cycle really this simple, neat and colorful? (NO) Created October 2, 2000, revised September 2001 melting pressure, heat Igneous
What is the law of conservation of matter? Law of conservation of matter states that matter cannot be created or destroyed. The changes that take place in the rock cycle never destroy or create matter. The elements are just redistributed in other forms.
Evidence #2: Dice Game Paste your log into your journal You will roll a minimum of10 times, and follow the directions on the dice at each station. Record each step in your log.
Stations #1 Compaction and Cementation #2 High Temperature and Pressure #3 Sediments #4 Igneous Rock #5 To The Surface #6 Metamorphic Rock #7 Sedimentary Rock #8 Melting #9 Cooling and Hardening #10 Magma #11 Weathering and Erosion
Evidence #3:What are Rocks? A rock is a naturally occurring solid mixture of one or more minerals, or organic matter Rocks are classified by how they are formed, their composition, and texture Rocks change over time through the rock cycle
ROCKS
Rock Types
Rock Types
Rock Types
Rock Types Believe it or not , rocks can be classified into groups -Just like living organisms The three main groups are: IGNEOUS SEDIMENTARY METAMORPHIC What are the clues to help classify rocks?
The Rock Cycle melting
The Rock Cycle
Igneous means “born of fire” Igneous Rocks Igneous means “born of fire”
Igneous Rocks Igneous rock begins as magma. Magma can form: When rock is heated When pressure is released When rock changes composition Magma freezes between 700 °C and 1,250 °C Magma is a mixture of many minerals http://www.fi.edu/fellows/payton/rocks/create/igneous.htm
VOLCANOES!!! Igneous!
Fig. 2.9 LAVA!!! MAGMA
Igneous Rocks Felsic: light colored rocks that are rich in elements such as aluminum, potassium, silicon, and sodium Mafic: dark colored rocks that are rich in calcium, iron, and magnesium, poor in silicon Coarse-grained: takes longer to cool, giving mineral crystals more time to grow Fine-grained: cools quickly with little to no crystals
Igneous Rocks - examples Coarse-Grained Fine-Grained Felsic Granite Rhyolite Mafic Gabbro Basalt
Igneous Rocks Intrusive Igneous Rocks: magma pushes into surrounding rock below the Earth’s surface Extrusive Rocks: forms when magma erupts onto the Earth’s surface (lava), cools quickly with very small or no crystals formed http://www.windows.ucar.edu/tour/link=/earth/geology/ig_intrusive.html&edu=high&fr=t
Mafic, fine grained, extrusive Obsidian What is Obsidian? Obsidian is a dark-colored volcanic glass that forms from the very rapid cooling of molten rock material. It cools so rapidly that crystals do not form. Igneous Rocks Obsidian is a dark-colored volcanic glass that forms from the very rapid cooling of molten rock material. It cools so rapidly that crystals do not form. Is this rock Felsic or Mafic? Is it fine-grained or coarse-grained? Is this rock Intrusive or Extrusive? Mafic, fine grained, extrusive
The Rock Cycle melting
The Rock Cycle
But then the EARTH’S elements Won’t leave The poor rock alone!
Ice wind Water ice wind water
They break up the stone
Sedimentary Rocks Sedimenary rock is formed by erosion Sediments are moved from one place to another Sediments are deposited in layers, with the older ones on the bottom The layers become compacted and cemented together http://www.fi.edu/fellows/payton/rocks/create/sediment.htm
Sedimentary Rock Sedimentary Rocks are formed at or near the Earth’s surface No heat and pressure involved Strata – layers of rock Stratification – the process in which sedimentary rocks are arranged in layers
Sedimentary Rock Chemical sedimentary – minerals crystallize out of solution to become rock Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO3) in the form of the mineral calcite. It most commonly forms in clear, warm, shallow marine waters. It is usually an organic sedimentary rock that forms from the accumulation of shell, coral, algal and fecal debris.
Sedimentary Rock Organic sedimentary – remains of plants and animals Coal is an organic sedimentary rock that forms from the accumulation and preservation of plant materials, usually in a swamp environment. Coal is a combustible rock and along with oil and natural gas it is one of the three most important fossil fuels.
Sedimentary Rock Clastic – made of fragments of rock cemented together with calcite or quartz Breccia is a term most often used for clastic sedimentary rocks that are composed of large angular fragments (over two millimeters in diameter). The spaces between the large angular fragments can be filled with a matrix of smaller particles or a mineral cement that binds the rock together.
The Rock Cycle melting
The Rock Cycle
Metamorphic Rock Meaning to change shape Changes with temperature and pressure, but remains solid Usually takes place deep in the Earth http://www.fi.edu/fellows/payton/rocks/create/metamorph.htm
Metamorphic Rocks Contact Metamorphism – heated by nearby magma Increased temperature changes the composition of the rock, minerals are changed into new minerals Hornfels is a fine-grained non-foliated metamorphic rock produced by contact metamorphism http://www.windows.ucar.edu/tour/link=/earth/geology/meta_contact.html&edu=h igh&fr=t
Metamorphic Rocks Regional Metamorphism – pressure builds up in rocks that is deep within the Earth Large pieces of the Earth’s crust collide and the rock is deformed and chemically changed by heat and pressure http://www.windows.ucar.edu/tour/link=/earth/geology/meta_regional.html&edu=high&fr=t
Metamorphic Rock Foliated - contain aligned grains of flat minerals Gneiss is foliated metamorphic rock that has a banded appearance and is made up of granular mineral grains. It typically contains abundant quartz or feldspar minerals.
Metamorphic Rock Non-Foliated – mineral grains are not arranged in plains or bands Marble is a non-foliated metamorphic rock that is produced from the metamorphism of limestone. It is composed primarily of calcium carbonate.
Metamorphic Rock Determine if the following rock samples are foliated or non-foliated: Quartzite Amphibolite Phyllite Foliated
The Rock Cycle melting
The Rock Cycle
Analysis Questions Reminder: Answer in complete sentences. What are rocks, and how are they created? What are the 3 natural processes involved in the rock cycle? How many times did you change into a different kind of rock? Describe 1 of the changes, naming the proccess(es) that caused the change.
Summary What did you think about what rocks are and where they come from before this lesson? What did you learn about what rocks are and where they come from from this lesson? (Minimum of 3 sentences!!!) What are some further thoughts or questions you have about what rocks are and where they come from?
Reflection Write a poem, narrative, or comic about a rock going though the rock cycle.
Big Idea Rocks are created and changed through a process called the rock cycle.