Rocks at Earth's surface that Earth has been moving for at least 2 billion years. These rocks have eroded and deposited, or laid down since Earth first took shape. All rock on Earth's surface is broken down by weathering and erosion. Weathered rock, or sediment is deposited in layers. The layers slowly change into sedimentary rock. Layers of sedimentary rock give hints to changes that were happening when the layers formed. They can show what the rock is and of & how the sediment is deposited.
The layers may also have fossils. A fossil is the remains or traces of a plant or animal that lived long ago. Fossils are usually found in sedimentary rock.
By studying fossils in rock layers, scientists can get an idea of how plates moved in Earth's past in a few ways.
1. Fossils of similar kinds of plants and animals have been found along the edges of different continents. Scientists believe that the fossils came from a time when those continents were joined. Over millions of years, they drifted away and the fossils were moved to new places.
2. Some fossils seem very far from where they formed. For example, fossils of fish have been found near the tops of mountains. Scientists believe that these fossils were by plate movements.
The layers may also have fossils. A fossil is the remains or traces of a plant or animal that lived long ago. Fossils are usually found in sedimentary rock.
By studying fossils in rock layers, scientists can get an idea of how plates moved in Earth's past in a few ways.
1. Fossils of similar kinds of plants and animals have been found along the edges of different continents. Scientists believe that the fossils came from a time when those continents were joined. Over millions of years, they drifted away and the fossils were moved to new places.
2. Some fossils seem very far from where they formed. For example, fossils of fish have been found near the tops of mountains. Scientists believe that these fossils were by plate movements.