Slow Changes to Earth’s Surface Weathering, Erosion, and Deposition from Ice, Water, and Wind.

Slow Changes to Earth’s SurfaceWeathering, Erosion, and Depositionfrom Ice, Water, and Wind

Weathering, Erosion, and Deposition

• Weathering?

• Erosion?

• Deposition?

• Weathering is the breaking down and wearing away of rock.

• Erosion is the movement of the weathered materials by ice, water, or wind.

• Deposition is the dropping off or depositing of the materials that were eroded by ice, water, and wind.

Weathering, Erosion, and Deposition by IceU-Valley Formation by a Glacier

Glaciers: U-Shaped Valleys

Glaciers: Fjords

Weathering, Erosion, and Deposition by Ice Formation of Fjords

• Fjords are created when glaciers retreat.

• The glaciers weather and erode the land, forming the U-shaped valley.

• The material is deposited in various locations in the valley.

• When the glacier retreats and sea levels rise, the water flows into (and fills) the valley floor.

Weathering, Erosion, and Deposition by Water: Canyons

Weathering, Erosion, and Deposition by Water: Caves

Weathering, Erosion, and Deposition by Water: Caves

• Caves can be formed by many processes, but erosion by water is one of the more common ways.

• In Texas, we have many limestone caves. Water enters the caves and weathers the rock by dissolving the limestone.

• When water levels rise, the minerals are carried away.

• Calcium carbonate is deposited when water precipitates through the limestone.

Weathering, Erosion, and Deposition by Water: Delta

Weathering, Erosion, and Deposition by Water: Delta

• A river delta forms at the mouth of a river.

• The flowing river has weathered and eroded the river bank and the river floor, carrying the sediment in the moving water.

• The sediment, that has been carried by the river, is deposited as the river flows into an ocean, sea, or estuary.

Weathering, Erosion, and Deposition by Wind: Sand Dunes

Weathering, Erosion, and Deposition by Wind: Sand Dunes

• A sand dune can form from the movement of water or wind.

• Most sand dunes have one side that is steeper than the other.

Movement of the sand dune

Wind direction

Weathering and Erosion by Wind: Hoodoos Pinnacles

Weathering and Erosion by Wind : Rock Arches

Weathering and Erosion by Wind : Rock Arches

1. Deep cracks form in sandstone. (Remember your observations of the frozen rock?)

2. Erosion wears away the exposed rock layers.

3. Water may enter the cracks, freeze, and widen the cracks further. Wind also wears away the rock particles.

4. Weathering and erosion continues until an arch, or bridge, remains.Over time, with continued weathering and erosion, the arches will collapse.

Weathering and Erosion by Wind

Weathering, Erosion, and Deposition by Wind and Water: Beaches

Weathering, Erosion, and Deposition by Wind and Water: Beaches

• Beaches are the result of wave action. • Waves or currents move the sand (or other sediments along

the shore). • Initially, the sediments on the beach were weathered and

eroded from rock. • Wind carried the sediment, and it is deposited either on the

land or in the water. • Sediment that is suspended in the water is carried in the water

by ocean currents and eventually, may be deposited on the shore by waves.

• The waves both deposit sand from the ocean bed and erode sand as the water pulls back into the ocean.

Weathering, Erosion, and Deposition by Wind and Water: Barrier Islands

Weathering, Erosion, and Deposition by Wind and Water: Sea Caves