Sediment is solid material that is moved and deposited in a new location. Sediment can consist of rocks and minerals, as well as the remains of plants and animals. It can be as small as a grain of sand or as large as a boulder.
Sediment moves from one place to another through the process of erosion. Erosion is the removal and transportation of rock or soil. Erosion can move sediment through water, ice, or wind.
Water can wash sediment, such as gravel or pebbles, down from a creek, into a river, and eventually to that river's delta. Deltas, river banks, and the bottom of waterfalls are common areas where sediment accumulates.
Glaciers can freeze sediment and then deposit it elsewhere as the ice carves its way through the landscape or melts. Sediment created and deposited by glaciers is called moraine.
Wind can move dirt across a plain in dust storms or sandstorms. Sand dunes are made of rocky sediment worn down by wind and collision with other sand particles.
Sediment is important because it often enriches the soil with nutrients. Areas rich in sediments are often also rich in biodiversity. Sedimentary soil is usually better for farming. Deltas and river banks, where much sediment is deposited, are often the most fertile agricultural areas in a region.
For thousands of years, the Nile River flooded yearly and brought with it 4 million metric tons (4.4 million short tons) of nutrient-rich sediment. The banks of the Nile are still Egypt's richest agricultural land.
Over millions of years, layers of sediment may build up and harden into sedimentary rock. Some of the many forms of sedimentary rock include sandstone, rock salt, and coal.
Sandstone forms as sand hardens. For centuries, sandstone has been mixed with sticky cement to form concrete. Concrete is an important construction material used for many buildings and roads.
Rock salt, also known as halite, forms as oceans evaporate. Oceans are made of salt water. When the water enters the atmosphere as vapor, it leaves the salt behind. The Bonneville Salt Flats, in the U.S. state of Utah, are flat desert areas covered by a layer of rock salt sediment. Lake Bonneville, the ancient sea that once covered the area, has long since evaporated.
Coal is a sediment that is made up of hardened plant debris. Coal, present on every continent except Antarctica, is found on the sites of former swamps and wetlands.
Sediment can accumulate in tea and coffee! The tiny materials left at the bottom of coffee mugs and teacupsthe remains of coffee grounds and tea leavesare a type of sediment called dregs.
to gather or collect.
the art and science of cultivating the land for growing crops (farming) or raising livestock (ranching).
layers of gases surrounding a planet or other celestial body.
a slope of land adjoining a body of water, or a large elevated area of the sea floor.
all the different kinds of living organisms within a given area.
hard material used as a building material or a binding agent for stronger building materials such as concrete.
dark, solid fossil fuel mined from the earth.
hard building material made from mixing cement with rock and water.
one of the seven main land masses on Earth.
flowing body of water that is smaller than a river.
remains of something broken or destroyed; waste, or garbage.
the flat, low-lying plain that sometimes forms at the mouth of a river from deposits of sediments.
to place or deliver an item in a different area than it originated.
area of land that receives no more than 25 centimeters (10 inches) of precipitation a year.
dry earth or soil.
a mound or ridge of loose sand that has been deposited by wind.
weather pattern of wind blowing dust over large regions of land.
to supply with valuable material.
act in which earth is worn away, often by water, wind, or ice.
to change from a liquid to a gas or vapor.
the art, science, and business of cultivating the land for growing crops.
able to produce crops or sustain agriculture.
to overflow or cover in water or another liquid.
mass of ice that moves slowly over land.
small stones or pebbles.
natural mineral form of salt (sodium chloride.) Also called rock salt.
the geographic features of a region.
inorganic material that has a characteristic chemical composition and specific crystal structure.
material, such as earth, sand, and gravel, transported by a glacier.
(5,592 kilometers/3,473 miles) river in East Africa.
substance an organism needs for energy, growth, and life.
large body of salt water that covers most of the Earth.
small piece of material.
very small, rounded rock.
flat, smooth area at a low elevation.
materials left from a dead or absent organism.
large stream of flowing fresh water.
natural substance composed of solid mineral matter.
natural mineral form of salt (sodium chloride.) Also called halite.
small, loose grains of disintegrated rocks.
common sedimentary rock formed by grains of sand compacted or cemented with material such as clay.
wind storm that blows great amounts of sand into the air.
large part of the ocean enclosed or partly enclosed by land.
solid material transported and deposited by water, ice, and wind.
rock formed from fragments of other rocks or the remains of plants or animals.
top layer of the Earth's surface where plants can grow.
land permanently saturated with water and sometimes covered with it.
visible liquid suspended in the air, such as fog.
flow of water descending steeply over a cliff. Also called a cascade.
area of land covered by shallow water or saturated by water.
movement of air (from a high pressure zone to a low pressure zone) caused by the uneven heating of the Earth by the sun.