Likeliest Locations. You’re most likely to find sedimentary rocks near sources of water, which is where a lot of erosion takes place. You can find different types in riverbeds, ponds and coasts and throughout the oceans.
Sedimentary rocks are formed on or near the Earth’s surface, in contrast to metamorphic and igneous rocks, which are formed deep within the Earth. The most important geological processes that lead to the creation of sedimentary rocks are erosion, weathering, dissolution, precipitation, and lithification.
Sedimentary rocks are formed from deposits of pre-existing rocks or pieces of once-living organism that accumulate on the Earth’s surface. If sediment is buried deeply, it becomes compacted and cemented, forming sedimentary rock.
Sediment is the loose sand, clay, silt and other. soil particles that settle at the bottom of a body of water. Sediment can come from soil erosion or from the decomposition of plants and animals. Wind, water and ice help carry these particles to rivers, lakes and streams.
Common sedimentary rocks include sandstone, limestone, and shale. These rocks often start as sediments carried in rivers and deposited in lakes and oceans. When buried, the sediments lose water and become cemented to form rock.
The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus (organic matter). The geological detritus originated from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes.
Sediment examples include boulders, pebbles, cobbles, sand, silt, and clay. Boulders, pebbles, and cobbles are types of gravel and are the largest sizes of sediment. Clay represents the smallest size of sediment because each particle is exceeding fine.
When minerals grow, they become larger. Some minerals grow into different shapes and have many different colors. Other minerals have no distinct shapes and only one color. Not all crystals are minerals.
Minerals can be identified based on a number of properties. The properties most commonly used in identification of a mineral are colour, streak, lustre, hardness, crystal shape, cleavage, specific gravity and habit. Most of these can be assessed relatively easily even when a geologist is out in the field.
Some minerals are elements (e.g. graphite, diamond, sulfur), but most are compounds. A mineral is any naturally-occurring crystalline substance.
