Weathering, Erosion, and Soil What type of rock is this, how can you tell?

Erosion Erosion The removal and transport of weathered materials by natural agents such as Caused by Glaciers Running water Gravity Wind Waves

Glaciers Mass of compacted ice and snow that moves under its own weight

Glaciers Friction at the base of the glacier is reduced by a thin film of melt water. Glaciers account for about 75% of the fresh water on Earth

Glaciers can leave behind large boulders that are known as an erratic

Glaciers Glaciers can move lots of sediment that can carve striations (grooves) into rocks These Striations show how glaciers moved

Glacial Deposits Drift or Till - all sediment that is deposited by glacial activity Loess: fine powder, pulverized rock, that blankets much of the northern mid-west Moraine: ridge or pile of boulders, gravel, sand, and silt left at the end of a glacier Esker: type of outwash that accumulates in the channels and tunnels of a glacier

Glacial Landforms Horne: a pyramid shaped peak where 3 or more cirques meet Cirque Steep-walled bowl-shaped depression

Glacial Landforms Trough U-shaped valley, Glaciers carve U shaped valleys

Glacial Landforms Arete Hanging valley Narrow flat-topped ridge that forms between two parallel troughs or cirques Hanging valley Straight drop-off at the end of a trough

Glacial Landforms Moraine: Pile of mixed sediments that have been carried and dropped by the glacier

Glacial Landforms Eskers -Mounds of rock from melt tunnels

Streams and Rivers Velocity - How fast the water moves Gradient - The steepness, the slope that a river or stream travels Discharge - The amount of water that moves past a certain point in a river in a given amount of time If there is a steep gradient, high velocity, and a large discharge, then Erosion will be severe! Rivers have energy to move lots of sediment, and even large boulders.

River stages affect: Velocity, Gradient, & discharge which cause Erosion

Seven Bends of the Shenandoah River meanders Bends in the river, shows how mature a river is. Is the Shenandoah and old river or a young river?

Erosion-Mass Movement The downward transportation of weathered materials by gravity Massive Landslide

Erosion-Mass Movement Creep Slump Mudflow/Earthflow Landslide/Rockslide

Erosion-Mass Movement: A large mass of sediment drops down!

Erosion-Mass Movement Creep Very slow movement of earth material. Caused by repeated freezing and thawing. Sediments are loosened by expanding frost and contracting thaw. Leaning fence posts and telephone poles are a sign of Creep.

Fence posts leaning due to creep

Erosion-Mass Movement Slump Slow downward movement of a large mass of soil Occurs when underlying sediments are weakened by heavy rains Characterized by a curved scar in the land surface.

Slump can cause road hazards

Erosion-Mass Movement Mudflow/Earthflow Thick pastes of sediments that travel downhill at great speeds Usually occur in dry areas that get a large quantity of rain all at once Leaves a cone shaped deposit

Mudflow in the Blue Ridge Mooreman’s Gap near Charlottesville

Erosion-Mass Movement Landslide/Rockslide Fast movement of large blocks of rock Occurs in very steep vertical cliffs Accelerated by ice wedging

At the bottom of an old rock slide in N.C. 2011

Wave Erosion The crashing of waves on a shoreline combined with storms continually shape the beach. This is a shoreline with erosion.

Wind and Waves Wind moves sand dunes at the beach and in the deserts.

Wind and Waves Wind can carve out landscapes as it carries sediment

Wind and Waves Many storms combine water and wind to cause significant erosion on landforms. Strong winds are capable of moving large amounts of sediment

Deposition: The process of dropping or depositing soil and sediments.