Rocks What are they The Rock Cycle 41515

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 rockforming minerals, such as quartz, feldspar, mica, or calcite • When you look closely, the sparkles you see are individual crystals of minerals.

Rock Types • There are three types of rocks Igneous Sedimentary Metamorphic

What is the rock cycle? • To show 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.

Ro c k C y c l e explains how Rocks and Natural Processes are related Metamorphic ng su lti re , me he at Sedimentary weathering pr es The 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 of 10 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 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!!!

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

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 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 (Ca. CO 3) 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 nonfoliated 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 nonfoliated metamorphic rock that is produced from the metamorphism of limestone. It is composed primarily of calcium

Metamorphic Rock • Determine if the following rock samples are foliated or non-foliated: Amphibolite Quartzite Phyllite Foliated

The Rock Cycle melting

The Rock Cycle

Analysis Questions Reminder: Answer in complete sentences. 1. What are rocks, and how are they created? 2. What are the 3 natural processes involved in the rock cycle? 3. 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 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.