rock types and rock cycle webquest answer key

Neter

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22-11-2024

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This article serves as an answer key for a webquest exploring rock types and the rock cycle. It's designed to be used alongside an interactive webquest activity, providing students with the correct answers and reinforcing their understanding of geology. Remember to always consult your specific webquest instructions as variations may exist.

I. Introduction: What are Rocks?

1. Define "rock" in your own words:

A rock is a naturally occurring solid aggregate of one or more minerals or mineraloids.

2. Name three common uses for rocks:

• Building materials (houses, roads)
• Tools and sculptures
• Landscaping (decorative stones)

II. The Three Main Rock Types

1. Igneous Rocks:

a. How are igneous rocks formed?

Igneous rocks are formed from the cooling and solidification of magma (molten rock beneath the Earth's surface) or lava (molten rock that has erupted onto the Earth's surface).

b. What are two examples of igneous rocks? Describe their textures.

• Granite: Coarse-grained, with large visible crystals due to slow cooling.
• Obsidian: Fine-grained or glassy, with no visible crystals due to rapid cooling.

2. Sedimentary Rocks:

a. How are sedimentary rocks formed?

Sedimentary rocks are formed from the accumulation and cementation of sediments (small pieces of rock, minerals, and organic matter). These sediments are transported by wind, water, or ice and then deposited in layers.

b. What are two examples of sedimentary rocks? Describe how they form.

• Sandstone: Formed from cemented sand grains (mostly quartz).
• Limestone: Formed from the accumulation of calcium carbonate (often from shells and skeletons of marine organisms).

3. Metamorphic Rocks:

a. How are metamorphic rocks formed?

Metamorphic rocks are formed from the transformation of existing rocks (igneous, sedimentary, or other metamorphic rocks) due to heat, pressure, and/or chemical reactions. This process occurs without melting the rock.

b. What are two examples of metamorphic rocks? Describe the changes they undergo.

• Marble: Formed from the metamorphism of limestone. The original calcite crystals recrystallize, becoming larger and interlocking.
• Slate: Formed from the metamorphism of shale. The clay minerals in shale are transformed into microscopic mica flakes, creating a layered texture.

III. The Rock Cycle

1. Draw a diagram of the rock cycle. Label all three rock types and the processes that transform them.

(This section requires a visual diagram. The diagram should show arrows illustrating the processes of melting, cooling, weathering/erosion, sedimentation, compaction/cementation, heat/pressure, and metamorphism, connecting the three rock types in a cyclical flow.)

2. Explain how each rock type can be transformed into another rock type:

• Igneous to Sedimentary: Igneous rocks weather and erode into sediments, which are then compacted and cemented to form sedimentary rocks.
• Sedimentary to Metamorphic: Sedimentary rocks are subjected to heat and pressure, transforming them into metamorphic rocks.
• Metamorphic to Igneous: Metamorphic rocks can melt to form magma, which then cools and solidifies to form igneous rocks.
• Igneous to Metamorphic: Igneous rocks can be subjected to heat and pressure, transforming them into metamorphic rocks.
• Sedimentary to Igneous: Sedimentary rocks can melt to form magma, which then cools and solidifies to form igneous rocks.
• Metamorphic to Sedimentary: Metamorphic rocks weather and erode into sediments, which are then compacted and cemented to form sedimentary rocks.

IV. Conclusion

1. What have you learned about rocks and the rock cycle?

(Students should summarize their understanding of the three main rock types, their formation processes, and how they are interconnected within the rock cycle. They should mention the role of heat, pressure, weathering, erosion, sedimentation, and cementation.)

This answer key provides a framework. Specific questions and answers in your webquest may differ. Always refer to your original webquest instructions for precise details. Remember to cite any external sources you used during your research.