Rock layers

Rock layers, called strata, are natural sheets of soil and rock that form over time through processes like sediment deposition, volcanic activity, and mineralization. They accumulate in a sequence, with the oldest layers at the bottom and newer ones on top, forming a kind of natural timeline. By studying these layers, scientists can learn about Earth's history, past climates, and events such as earthquakes or volcanic eruptions. The characteristics of each layer—its composition, fossils, and arrangement—help tell the story of how the Earth's surface has changed over millions of years.