Sedimentary formations are layers of rock that are created from the accumulation of sediments over time. These sediments can include particles from weathered rocks, minerals, and organic materials. As these materials settle in bodies of water or on land, they compact and cement together, forming distinct layers that can vary in thickness and composition. These formations are important for understanding Earth's history, as they often contain fossils and clues about past environments. Common types of sedimentary rocks include sandstone, limestone, and shale. Studying these formations helps geologists learn about ancient climates and the processes that shaped the planet.