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.

Sedimentary Rock

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
Sediment that is light enough to be carried by water without touching the stream bed is called suspended sediment, and is visible as cloudy or milky areas of water.

Dregs
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.

accumulate
Verb

to gather or collect.

Noun

the art and science of cultivating the land for growing crops (farming) or raising livestock (ranching).

ancient
Adjective

very old.

Noun

layers of gases surrounding a planet or other celestial body.

bank
Noun

a slope of land adjoining a body of water, or a large elevated area of the sea floor.

Noun

all the different kinds of living organisms within a given area.

boulder
Noun

large rock.

cement
Noun

hard material used as a building material or a binding agent for stronger building materials such as concrete.

coal
Noun

dark, solid fossil fuel mined from the earth.

concrete
Noun

hard building material made from mixing cement with rock and water.

Noun

one of the seven main land masses on Earth.

creek
Noun

flowing body of water that is smaller than a river.

debris
Noun

remains of something broken or destroyed; waste, or garbage.

Noun

the flat, low-lying plain that sometimes forms at the mouth of a river from deposits of sediments.

deposit
Verb

to place or deliver an item in a different area than it originated.

Noun

area of land that receives no more than 25 centimeters (10 inches) of precipitation a year.

dirt
Noun

dry earth or soil.

Noun

a mound or ridge of loose sand that has been deposited by wind.

dust storm
Noun

weather pattern of wind blowing dust over large regions of land.

enrich
Verb

to supply with valuable material.

Noun

act in which earth is worn away, often by water, wind, or ice.

evaporate
Verb

to change from a liquid to a gas or vapor.

farming
Noun

the art, science, and business of cultivating the land for growing crops.

fertile
Adjective

able to produce crops or sustain agriculture.

flood
Verb

to overflow or cover in water or another liquid.

Noun

mass of ice that moves slowly over land.

gravel
Noun

small stones or pebbles.

halite
Noun

natural mineral form of salt (sodium chloride.) Also called rock salt.

Noun

the geographic features of a region.

mineral
Noun

inorganic material that has a characteristic chemical composition and specific crystal structure.

Noun

material, such as earth, sand, and gravel, transported by a glacier.

Nile River
Noun

(5,592 kilometers/3,473 miles) river in East Africa.

Noun

substance an organism needs for energy, growth, and life.

Noun

large body of salt water that covers most of the Earth.

particle
Noun

small piece of material.

pebble
Noun

very small, rounded rock.

Noun

flat, smooth area at a low elevation.

remains
Noun

materials left from a dead or absent organism.

Noun

large stream of flowing fresh water.

rock
Noun

natural substance composed of solid mineral matter.

rock salt
Noun

natural mineral form of salt (sodium chloride.) Also called halite.

sand
Noun

small, loose grains of disintegrated rocks.

sandstone
Noun

common sedimentary rock formed by grains of sand compacted or cemented with material such as clay.

sandstorm
Noun

wind storm that blows great amounts of sand into the air.

Noun

large part of the ocean enclosed or partly enclosed by land.

Noun

solid material transported and deposited by water, ice, and wind.

sedimentary rock
Noun

rock formed from fragments of other rocks or the remains of plants or animals.

soil
Noun

top layer of the Earth's surface where plants can grow.

Noun

land permanently saturated with water and sometimes covered with it.

vapor
Noun

visible liquid suspended in the air, such as fog.

Noun

flow of water descending steeply over a cliff. Also called a cascade.

Noun

area of land covered by shallow water or saturated by water.

wind
Noun

movement of air (from a high pressure zone to a low pressure zone) caused by the uneven heating of the Earth by the sun.