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Lava flows and shallow intrusive igneous rocks have grains than deep intrusive rocks.

a) Finer
b) Coarser

User JamesT
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Final answer:

Lava flows and shallow intrusive igneous rocks have coarser grains compared to deep intrusive rocks. This is because the slow cooling process allows larger mineral grains to form. In contrast, extrusive rocks cool quickly, resulting in fine-grained textures.

Step-by-step explanation:

Lava flows and shallow intrusive igneous rocks have coarser grains than deep intrusive rocks. When magma cools slowly over thousands to millions of years, it allows time for larger mineral grains to form, resulting in a coarse-grained rock. These rocks are called intrusive or plutonic rocks. On the other hand, extrusive igneous rocks cool quickly on the surface, resulting in fine-grained rocks.

Lava flows and shallow intrusive igneous rocks cool relatively quickly, and as a result, they have finer grains compared to deep intrusive rocks. Deep intrusive igneous rocks, such as granite, form from magma that cools slowly over thousands to millions of years, giving enough time for large crystals to grow, resulting in a coarse-grained texture.

User Sachin Titus
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