Rock Cycle Part 1: Minerals and Rock Types Notes Student Learning Objective: By the end of the lesson, students should be able to: Define and explain the properties of minerals. Identify processes and forces that change one rock type into another. Explain the role of tectonic forces in the rock cycle. Identify the sources of energy that drive the rock cycle.

What is a Mineral? •Natural, solid material found on Earth that are the building blocks of rock; each has a certain chemical makeup and set of properties that determine their use and value.

Properties of Minerals There are more than 4000 different minerals, but only about 400 are common To be classified as a mineral, a substance must have the following characteristics: 1.Must occur naturally (not man made) •Cement and brick consist of natural substances, but they are made by humans.

Properties of Minerals 2. Inorganic - cannot be formed from things that were once living •Coal forms naturally, but it is made from plant and animal remains. 1.Solid - must be a object with a definite shape and volume 4. Crystal structure –the particles in a mineral line up in a pattern that repeats itself over and over Ex.Cubic,Tetragonal, Hexagonal

Mineral Properties Definite chemical composition – always contains the certain elements in definite proportions

Identifying Minerals Each mineral has its own specific Physical properties that can be used to identify it. -Hardness - Density -Color -Crystal System -Luster - Cleavage and Fracture -Streak - Texture -Special Property

Physical Properties 1. Hardness Mohs hardness scale Used to rank 10 minerals from softest to hardest

Mohs Hardness Scale Mineral Rating Testing Method Talc 1 Softest known mineral. Scratched by fingernail Gypsum 2 A fingernail can easily scratch. Calcite 3 A fingernail cannot scratch, but a penny can. Fluorite 4 A steel knife can easily scratch it. Apatite 5 A steel knife can scratch it. Feldspar 6 Steel knife cannot scratch it, it can scratch glass Quartz 7 Can scratch steel and hard glass Topaz 8 Can scratch quartz Corundum 9 Can scratch topaz Diamond 10 Hardest known mineral. Can scratch all other substances.

Physical Properties 2. Color- can be used only to identify those minerals that have their own special color Can be easily observed. Some minerals maintain the same color. Azurite is always blue. Some minerals can occur in a variety of colors. Calcite comes in many colors

Physical Properties 3. Streak-The streak of a mineral is the color of it’s powder. Observe streak by rubbing a mineral against a piece of tile. Streak color and mineral color are often different. Streak color does not vary!!

Physical Properties 4. Luster is the term used to describe how a mineral reflects light from its surface. Words used to describe luster are listed below: Shiny - Earthy Glassy - Pearly Waxy - Metallic

Physical Properties 5. Density – no matter how large or small a mineral is its density is always the same 6. Crystal system – sometimes you can see the crystal pattern, but many times it is visible only under a microscope

Physical Properties Cleavage / fracture – the way a mineral breaks apart. Cleavage (smooth flat surfaces). Fracture (jagged or rough edges) Special properties – some minerals have special properties such as magnetism, electrical properties, radioactivity and fluorescence

B. How Are Different Rock Types Formed by the Rock Cycle? Earth is made of natural solid materials known as rocks. For example, granite, basalt, limestone, sandstone, marble, and gneiss are common types of rock found in Earth’s crust. When we think of rocks, many of us think of objects that are solid, stable, and unchanging. All rocks form from other rocks. Thus, old or stable rocks must also change into new rocks over time.

B. How Are Different Rock Types Formed by the Rock Cycle? There are three basic types of rock: sedimentary, igneous, and metamorphic. These categories are based on origin, or how the rocks formed. The new and old rocks are also classified based on their composition and characteristics. Igneous rocks form when molten, liquid rock turns solid. Volcanic (extrusive) rocks are igneous rocks that form on Earth’s surface. Plutonic (intrusive) rocks are igneous rocks that form underground.

B. How Are Different Rock Types Formed by the Rock Cycle? Sedimentary rocks form when broken pieces of other rocks (called sediment) accumulate and are then cemented together naturally to form a new rock. Other Earth materials–such as pieces of plant material or shells–can also be considered sediment and can become part of sedimentary rocks. Some sedimentary rocks form when minerals that are dissolved in water crystallize out of the water. Metamorphic rocks form when rocks or minerals are exposed to high temperatures and tremendous pressure over time. Pressure can also cause changes to a rock’s texture, producing a new metamorphic rock.

B. How Are Different Rock Types Formed by the Rock Cycle? Rocks are further classified based on their composition (the types of minerals and/or other materials that a rock is made of) and texture (the size, shape, and arrangement of the mineral grains and/or other materials in the rock). All three types of rock may be changed by the processes of the rock cycle. These processes continuously recycle rocks, changing them from one type to another, or to new varieties of the same type. The rock cycle is the process by which rocks are created, transformed, and recycled to form new rocks.

B. How Are Different Rock Types Formed by the Rock Cycle? Overall, three fundamental forces drive the rock cycle. These forces are the sun, Earth's gravity, and Earth's internal heat. Other processes that play a role in the rock cycle include tectonic plate movement, metamorphism, and volcanism. The rock cycle has been at work since Earth formed more than 4.5 billion years ago. Rocks will continue to transform into other rocks for billions of years to come. Minerals Types of Rocks

Rock Cycle Part 2: Rock Cycle and its Processes Notes Student Learning Objective: By the end of the lesson, students should be able to: Identify processes and forces that change one rock type into another. Explain the role of tectonic forces in the rock cycle. Identify the sources of energy that drive the rock cycle.

What Processes Cause Rocks to Transform into Other Types of Rock? As existing rock moves through the rock cycle, it can be physically moved, broken, dissolved, or melted. The existing rock or remains of existing rock can be precipitated, solidified, compressed and cemented, or physically or chemically rearranged to form new rock. Each of these transformations is one part of the rock cycle. The main processes that alter and transform rocks as part of the rock cycle are: Weathering, Erosion, and Deposition: Responsible for turning existing rock into sediment and transporting it to new locations Compaction or Compression and Cementation: Responsible for turning sediment into sedimentary rock

What Processes Cause Rocks to Transform into Other Types of Rock? Melting: Responsible for turning existing rock into magma or lava Solidification or Crystallization: Responsible for turning magma or lava into igneous rock Heat and/or Pressure: Responsible for causing physical and/or chemical changes that alter the composition and/or texture of existing rock to form new metamorphic rock

What Processes Cause Rocks to Transform into Other Types of Rock? Rock Cycle Process: There is no one particular start or end point in the rock cycle, however, it is a process. When rock is exposed on Earth’s surface, weathering will break it down. If the rock is subjected to chemical weathering, it may be dissolved into a solution.

What Processes Cause Rocks to Transform into Other Types of Rock? The solution will flow somewhere else (erosion). When the solution evaporates, it will deposit the dissolved material as crystals of evaporite minerals (minerals made through evaporation). These crystals will build up over time to become new sedimentary rocks classified as chemical sedimentary rocks. If the rock is subjected to mechanical weathering (also known as physical weathering), it will be broken into smaller pieces.

What Processes Cause Rocks to Transform into Other Types of Rock? The pieces will be eroded (carried away) and deposited as sediment somewhere else. If this sediment is buried and compacted, then cemented together, it will become a new sedimentary rock. If existing rock is buried under enough layers of other rock and sediment, it can be exposed to Earth's internal heat and pressure. If rock is exposed to enough heat, it can melt completely, forming magma. Magma can rise higher within the lithosphere, where it will cool slowly, forming igneous rocks with large crystals.

What Processes Cause Rocks to Transform into Other Types of Rock? Magma can also rise all the way through and onto Earth’s surface, becoming lava and cooling very quickly to form igneous rocks with small crystals or glassy textures. This process is called volcanism. If rock is exposed to some heat, but not enough to melt, it can still change. Heat can cause chemical changes that alter the composition of the rock. These chemical changes can also occur through the release of fluids within the rock, or the addition of fluids from the surrounding lithosphere.

What Processes Cause Rocks to Transform into Other Types of Rock? Pressure can cause chemical changes by squeezing rocks hard enough to cause the release of fluids, or by rearranging the internal atoms within the minerals in the rock. Pressure can also cause changes to the texture of a rock by creating a much denser arrangement of grains. For example, shale is a sedimentary rock made of loosely arranged mud grains, and produces a dull thud when you tap on it with your knuckles. When shale is exposed to high pressure, the grains are compressed into a much denser arrangement, producing the metamorphic rock slate. The process of turning existing rocks into metamorphic rocks is called metamorphism.

B. How Does the Movement of Tectonic Plates Contribute to the Rock Cycle? Earth's crust is broken into several large landmasses known as tectonic plates. As tectonic plates float on the denser mantle below, they slowly move across Earth’s surface. The motions of tectonic plates result in processes that are important in the rock cycle. Putting It All Together Plate tectonics is a major driving force of the rock cycle. It is the main cause of the pressure involved in metamorphism. Through uplift, rocks are brought to the surface to be exposed to weathering and erosion. Through subduction, rocks are brought below the surface to be exposed to heat, causing metamorphism and melting. These and the other processes of the rock cycle create, alter, and destroy rocks, constantly cycling rocks within and between the igneous, metamorphic, and sedimentary rock types.

C. Where Does the Energy That Drives the Rock Cycle Com From? All changes in nature require energy to flow from one place to another. The rock cycle is no exception. Overall, two fundamental forces drive the rock cycle: thermal energy and gravity. Thermal Energy The flow of thermal energy, commonly known as heat, is particularly important in the rock cycle. The thermal energy that drives the rock cycle comes from two main sources: Earth’s interior and the sun.

C. Where Does the Energy That Drives the Rock Cycle Com From? The sun provides the thermal energy that heats Earth’s atmosphere and surface. This thermal energy drives Earth’s weather and the water cycle. Wind and water are both powerful agents of weathering and erosion. Earth’s interior is also a source of thermal energy that drives the rock cycle. This thermal energy is the result of radioactivity within Earth’s crust, mantle, and core. Thermal energy in Earth’s interior causes convection in the soft material in the mantle. This, in turn, causes the tectonic plates floating on the mantle to move.

C. Where Does the Energy That Drives the Rock Cycle Com From? Thermal energy causes rocks to change and melt. When magma moves closer to the surface, the transfer of thermal energy causes it to cool and solidify into igneous rocks. Gravity pulls denser rocks down toward Earth’s center. This causes less dense rocks and magma to move upward toward the surface. Rocks are lifted up from underground through tectonic plate movement. Ultimately, it takes gravity and thermal energy working together to drive the rock cycle. Watch