A scientist is trying to determine where fault lines are to assess the risk of earthquakes and volcanic activity in an area. Which tool will be the most helpful to him?

A geologic map shows the types, ages, and arrangement of rocks and features such as faults. That makes it the most useful tool for locating fault lines and assessing related earthquake and volcanic risks. A topographic map shows surface elevation, while a radiation detector and density meter do not map faults.

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