Weathering, Erosion, Deposition

A river flowing across the rocky surface of the Earth could create which of the following?

• Dunes

• Mountain

• Canyon

• Hill

How could students best model the formation and movement of dunes?

• Pour water over piles of sand.

• Slowly drip wet sand into a tub of water.

• Use a spoon to dig a hole in a tray of sand.

• Use straws and blow piles of sand.

Students propped up one end of a tray of sand. They also set up a water jar and rubber hose siphon system, so that water flowed over the sand. They observed how the moving water carried the sand downhill and made a small pile of sand at the bottom of the tray. When the students created the small pile of sand at the end of the flow of water, they modeled the formation of which of the following?

• Dunes

• Canyon

• Plain

• Delta

What natural force formed the Grand Canyon by slowly cutting through the rock over many millions of years?

• A boulder

• A glacier

• A river

• A landslide

A delta is made of sediments deposited at the mouth of a river. A delta forms where the river meets the ocean because the ocean -

• makes the river slow down and deposits sediment

• contains salt water and rivers have fresh water

• is usually much colder than the water in the river

• has powerful currents that weather rock on the shore

Sand dunes are created when sand is moved and deposited by –

• strong, persistent winds

• slow moving sheets of ice

• frequent lava flows

• powerful ocean currents

Rivers create landforms as they move across the surface of the Earth. Rivers move as water flows from -

• high in the mountains, down to oceans and lakes

• regions that have warmer temperatures to cooler ones

• because they are pushed by strong winds

• from east to west as the earth rotates

A delta is made of sediments deposited at the mouth of a river. The delta is formed when –

• moving water slows down

• blowing winds cool the land

• drifting clouds produce rain

• crashing waves erode soil

Freeport, Texas, is built on a growing delta at the mouth of the Brazos River. The land on which Freeport is built continues to grow because the Brazos River –

• deposits new material on the delta

• removes sediments from the delta

• moves farther away from the delta

• receives fresh water from the delta

Which forces create landforms such as deltas, dunes, and canyons?

• Volcanic eruptions

• Earthquakes and landslides

• Planetary movements

• Moving wind and water