Why are time periods on the geologic time scale not even in length? (1 point)
• They are based on important events that happened in Earth's history.
• They are based on a different type of calendar used to track Earth's history.
O They are based on the thickness of the Earth's rock layers
© They are based on the type of fossils found in rock layers of the Earth
• They are based on important events that happened in Earth's history.
The correct answer is:
• They are based on important events that happened in Earth's history.
The correct answer is: They are based on important events that happened in Earth's history.
The geologic time scale, which organizes Earth's history into different time periods, is not evenly divided because it is based on significant events that occurred in Earth's past. These events include major geological transformations, mass extinctions, the emergence of new life forms, and other important milestones.
To determine the length of each time period, geologists and paleontologists analyze the rock layers and fossils found in them. By studying the different layers of rocks and the fossils they contain, scientists can identify distinct time intervals characterized by specific geological and biological changes. Each time period is given a name and represents a distinct chapter in Earth's history.
So, the uneven length of the time periods on the geologic time scale is a result of the importance and significance of the events that took place during those periods, rather than being based on the thickness of rock layers or a different type of calendar.