sedimentikivi

Sedimentikivi is the Estonian term for sedimentary rock. Sedimentary rocks are a major class of rock which, along with metamorphic and igneous rocks, makes up most of the Earth's crust. They are formed by the accumulation and cementation of mineral or organic particles on the Earth's surface. These particles are derived from pre-existing rocks that have been broken down by weathering and erosion.

The process of sedimentary rock formation typically begins with the breakdown of existing rocks through physical and chemical weathering. These weathered fragments, along with organic material, are then transported by agents such as water, wind, or ice to a depositional basin. Over time, layers of sediment accumulate. As more sediment is added, the lower layers are compacted by the weight of the overlying material. Dissolved minerals in groundwater can then precipitate between the sediment grains, acting as a natural cement that binds the particles together. This process is known as lithification.

Common types of sedimentary rocks include sandstone, shale, limestone, and conglomerate. Sandstone is composed primarily of sand-sized grains, while shale is made of fine-grained particles like silt and clay. Limestone is typically formed from the accumulation of marine organism shells and skeletal fragments, or through chemical precipitation. Conglomerate consists of rounded pebbles and cobbles cemented together. Sedimentary rocks are significant because they often preserve fossils, providing valuable insights into Earth's history and the evolution of life. They also often contain important natural resources like coal, oil, and natural gas.