Final answer:
Major events allow geologists to organize Earth's history by providing distinct reference points in the Earth's strata. They define specific periods, mark the transition between different eras and aid in understanding the Earth's geological timeline.
Step-by-step explanation:
Major events are significant because they provide geologists with a framework to organize Earth’s history in a logical way. These events, such as volcanic eruptions or massive earthquakes, play an important role in shaping the Earth's geological record. They define specific periods of time by creating distinct layers in the Earth's strata which can be traced and studied to understand the geological timeline.
For example, the extinction of the dinosaurs marks the boundary between the Cretaceous and Tertiary periods. The asteroid impact that caused this extinction event left a layer of iridium, an element which is rare in the Earth's crust but abundant in asteroids, spread globally. This layer in the Earth's strata is used as a global reference point for the end of the Mesozoic Era.
In conclusion, major events serve as reference points for scientists to create a chronological framework of Earth's history, using these 'snapshots in time' to analyze and date different aspects of our planet's geological past.
Learn more about Geological timeline