Intrusive and Extrusive Rock Worksheet

Are you a geology enthusiast or a student looking to expand your knowledge of intrusive and extrusive rocks? If so, you've come to the right place! This blog post will introduce you to a helpful worksheet designed to deepen your understanding of these fascinating geological entities and their distinguishing characteristics. So, let's dive in and explore the world of intrusive and extrusive rocks together!

  Difference Between Intrusive and Extrusive Igneous Rocks

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  Formation of Intrusive and Igneous Rocks

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  Intrusive and Extrusive Igneous Rocks

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  Igneous Rock Formation Diagram

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  Igneous Rocks with Crystals

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What is the main difference between intrusive and extrusive rocks?

The main difference between intrusive and extrusive rocks lies in their formation processes. Intrusive rocks are formed beneath the Earth's surface through the slow cooling of magma, resulting in coarse-grained textures. On the other hand, extrusive rocks are formed on the Earth's surface through the rapid cooling of lava, leading to fine-grained textures.

How are intrusive rocks formed?

Intrusive rocks are formed when molten magma, which originates beneath the Earth's surface, cools and solidifies slowly within the crust, creating large, crystalline structures. This process occurs deep underground, where the magma has time to cool and crystallize before reaching the surface. Over time, weathering and erosion can expose these once-buried intrusive rocks at the Earth's surface.

How are extrusive rocks formed?

Extrusive rocks are formed through volcanic activity. When magma reaches the Earth's surface through volcanic eruptions, it cools quickly and solidifies to form fine-grained rocks such as basalt or rhyolite. This rapid cooling at the surface prevents large mineral crystals from forming, resulting in the characteristic fine texture of extrusive rocks.

What are some examples of intrusive rocks?

Some examples of intrusive rocks include granite, diorite, gabbro, and pegmatite. These rocks are formed beneath the Earth's surface through the cooling and solidification of magma. Intrusive rocks have coarse-grained textures due to their slow cooling process, and their presence can often be seen in mountain ranges and other geologically active areas.

What are some examples of extrusive rocks?

Some examples of extrusive rocks include basalt, rhyolite, and andesite. These rocks are formed from magma that cools and solidifies quickly on the Earth's surface, resulting in fine-grained textures. Extrusive rocks are commonly found in volcanic areas where lava flows reach the surface and cool rapidly.

What are the characteristics of intrusive rocks?

Intrusive rocks are characterized by their formation beneath the Earth's surface through the slow cooling and solidification of magma. They have large mineral crystals due to the longer cooling time, are coarse-grained in texture, and are typically more resistant to weathering and erosion compared to extrusive rocks. Intrusive rocks can range from granites to diorites and gabbros, depending on their mineral composition and intrusive environment.

What are the characteristics of extrusive rocks?

Extrusive rocks are formed from lava that cools quickly on the Earth's surface, resulting in fine-grained textures. These rocks are often mafic in composition and typically contain minerals like basalt, andesite, or rhyolite. They exhibit porphyritic textures, with large crystals (phenocrysts) embedded in a fine-grained matrix. Extrusive rocks are commonly found in volcanic regions and can also contain vesicles, which are gas bubbles trapped in the rock during the rapid cooling process.

How does the cooling rate differ between intrusive and extrusive rocks?

The cooling rate differs between intrusive and extrusive rocks based on their location of formation. Intrusive rocks, which form underground, cool slowly over thousands to millions of years due to the insulating properties of the surrounding rock. This slow cooling allows for the growth of large mineral crystals. On the other hand, extrusive rocks, which form on the Earth's surface, cool rapidly over a matter of days to weeks since they are exposed to cooler temperatures. This rapid cooling results in the formation of fine-grained or glassy textures in extrusive rocks.

What is the texture of intrusive rocks?

Intrusive rocks have a coarse texture due to their slow cooling process beneath the Earth's surface, allowing large mineral crystals to form. This texture is characterized by visible interlocking mineral grains that are typically several millimeters to centimeters in size, giving the rock a rough and grainy appearance.

What is the texture of extrusive rocks?

Extrusive rocks have a fine texture due to their rapid cooling at the Earth's surface. This quick cooling process prevents large mineral crystals from forming, resulting in a smooth and uniform structure in the rock.