The Solid Earth Unit Two Part One Big

The Solid Earth Unit Two Part One

Big Ideas Solid Earth is comprised of: - The Rock Cycle - Rocks and Minerals - Soils and Landforms - Plate Tectonics Theory - Layers of Our Planet - Earthquakes and Volcanoes

LET’S GO! We will start with - The Rock Cycle - How to Identify Rocks and Minerals - Weathering and Erosion

The Rock Cycle

The Rock Cycle is made up of three types of rocks. - Igneous - Sedimentary - Metamorphic

What’s a Rock? Rocks are any solid mass of mineral or minerallike matter that occurs naturally as part of our planet. Rocks give us a basic knowledge of the Earth. So time, weathering, climate patterns, etc. Why are they important?

The Rock Cycle Because Earth is a system and works off of itself, this cycle was formed.

The interactions between Earth’s water, air, and land can cause rocks to change from one type to another. The continuous processes that cause rocks to change is what makes the rock cycle.

Once weathered, these sediments form sedimentary rock When rock is changed by heat and pressure, it forms Metamorphic rocks Magma is molten material that forms deep beneath Earth’s surface. These igneous rocks travel to Earth’s surface, where they are weathered and turned into sediments When magma cools, Igneous rocks are formed

Alternative Paths

Three Major Forms of Rocks Igneous rocks Sedimentary rocks Metamorphic rocks

Questions Are metamorphic and igneous rocks formed by internal or external heat from Earth? What about sedimentary rocks? Internal or external heat?

Igneous Rocks The word igneous comes from the Latin word ignis, which means “fire” Intrusive and Extrusive Igneous Rocks Granite Basalt

How to classify igneous rocks

Coarse – grained • The slow cooling of magma cause large crystals to form Fine – grained • Rapid cooling of magma cause smaller crystals to form Glassy texture • Made when magma cools on Earth’s surface Porphyritic texture • Different sized crystals in a igneous rock due to rapid and slow cooling of that rock

How would you classify? Granite – coarse grained Obsidian – glassy Andesite – fined grained Porphyritic rhyolite – multi – grained

Granite rocks will have quartz and feldspar minerals (white colored) Basaltic rocks will have magnesium and iron minerals (dark colored)

Summary of Igneous Rocks They form when magma or lava cools and hardens Two forms • • Intrusive rocks (formed below Earth’s surface) Extrusive rocks (formed on Earth’s surface) Igneous rocks are classified four ways: 1. 2. 3. 4. Coarse-grained Fine-grained Glassy texture Porphyritic texture

Features of Igneous Rocks

Compaction and Cementation After sediments are deposited in a certain area, they often become lithified. • This means that they are turned into rock!

Classification of Sedimentary Rocks TWO main groups… • Clastic Sedimentary Rocks • Chemical Sedimentary Rocks

Clastic Rocks These are rocks that are formed due to the weathered bits of rocks and minerals around them.

Chemical Rocks This group forms when dissolved minerals precipitate from water solutions

Features of Sedimentary Rocks

Sedimentary Rocks All sedimentary rocks begin to form when existing rocks break down. • When rocks break apart, they leave little pieces of themselves and these are compacted on top of each other, carried away, and turn into rocks

Formation of Sedimentary Rocks Sedimentary rocks form when solids settle out of a fluid, such as water or air. • Several Major processes contribute to formation of sedimentary rocks…

Weathering, Erosion, and Deposition Weathering is the first step in making sedimentary rocks. • Chemical Weathering and Physical weathering help break apart existing rocks to form these sedimentary rocks. Erosion involves weathering and the removal of rock.

Sculpturing the Earth’s Surface The Earth’s surface is always changing Internal forces move the surface up and down. At the same time, external forces break apart the surface. The breaking down and changing of rocks at or near Earth’s surface is called…

Weathering Two forms of weathering • Mechanical • Chemical How are they different?

Mechanical Weathering Mechanical weathering occurs when physical forces break rock into smaller and smaller pieces without changing the rock’s mineral composition.

Types of Mechanical Weathering Frost wedging • When water freezes it expands. When water is in nature, it works its way into all the cracks and pours it can and causes these cracks and pours to expand when it freezes.

Unloading • Large masses of igneous rock may be exposed through uplift and erosion of overlying rocks. When this happens, the pressure exerted on the igneous rock is reduced.

Biological Activity • This is the process by which plants, animals, or humans can mechanical weather things around them.

Chemical Weathering Chemical weathering is the transformation of rock into one or more new compounds.

Types of Chemical Weathering Water • Water is the most important agent of chemical weathering. • It promotes chemical weathering by absorbing the gases from the atmosphere and ground.

Examples of Each

Rate of Weathering Mechanical weathering affects the rate of chemical weathering! Weathering is also controlled by rock characteristics and climate

Physical characteristics of the rock, such as cracks, are important for weathering because it gives water an opening into the rock. Also, if the rock is harder it won’t weather as fast.

Agents of Erosion WATER WIND ICE GRAVITY

YOUR ASSIGNMENT Tell me about each of the agents of erosion. Two pages total in length and tell me about how each weather the different rocks (igneous, sedimentary, metamorphic) ---- or---Draw a picture of each “agent of erosion, ” color and write a brief statement of what their powers are. Ice Wind Water Gravity

CHECK POINT Name three types of rocks and how they are connected to each other. What are types of weathering and how do they affect coastal regions?

Minerals are what make up rock. - common rock-forming minerals are quartz feldspar biotite calcite hornblende

Minerals defined Minerals in Earth science are different than minerals in our food. • A mineral is a naturally occurring, inorganic solid with an orderly crystal structure and a definite chemical composition… • Naturally occurring means it was formed in nature. • Inorganic solid means a solid found in nature. • Orderly crystal structure means their atoms and ions are arranged in an orderly and repetitive manner • Definite chemical composition means they are made of two or more elements

What one is a mineral? Why?

How minerals are formed FOUR MAJOR PROCESSES 1. Crystallization from magma 2. Precipitation 3. Changes in pressure and temperature 4. Formation from hydrothermal solutions

1. Crystallization from magma Magma is molten rock, formed deep in Earth. Once cooled, minerals such as iron, calcium and magnesium are formed.

2. Precipitation Once water is soaked into the Earth’s soil, it takes little minerals with it. When the water evaporates, it leaves behind minerals that bond together.

3. Pressure and temperature High pressure and high temperature cause minerals to compact into each other tightly to form things like talc.

4. Hydrothermal Solutions This is a very hot mixture of water and dissolved substances.

Mineral Groups Minerals are classified into groups based on their composition

Properties of Minerals Color Streak Luster Crystal Form Hardness Cleavage Fracture Density Distinctive Properties of Minerals

P O t ar f o ne M A EX