What is Weathering, Erosion and Deposition?? Winds sweeping through the Grand Canyon have eroded this sandstone outcrop into an anvil shape. Wind shapes these fantastical forms by eroding less dense rock, like sandstone, faster than surrounding rock.

Weathering and Erosion S:\FACULTY\6th Science\Weathering and Erosion\erosion.asf A thunderstorm does its part to shape Utah's Mussentuchit Badlands. Although this area gets only scant rainfall, over centuries, precipitation and wind have taken turns creating this rugged land's hundreds of gullies, ravines, and washes.

A waterfall fed by glacial runoff tumbles over sheer cliffs and into the turquoise water of Admiralty Inlet on Baffin Island, Nunavut, Canada. Such moving water is among the most powerful of nature's landscape-altering tools

Sandbars swirl beneath Oregon Inlet in Cape Hatteras National Seashore on North Carolina's Outer Banks. Waves driven by ocean winds can cause the sandbars here to shift and change literally by the hour, making conditions hazardous for boats.

The Mississippi River Delta is the modern area of land (the river delta) built up by sand deposited by the Mississippi River as it slows down and enters the Gulf of Mexico. The deltaic process has, over the past 5,000 years, caused the coastline of south Louisiana to advance gulfward from 15 to 50 miles (24 to 80 km).modernriver deltaMississippi RiverGulf of Mexico S:\FACULTY\6th Science\Weathering and Erosion\deltas.asf

With the snow-draped Sierra Nevada as a backdrop, unique erosion formations called sand tufa stand like giant cauliflower stalks in a dry Arizona lake bed. Before this alkaline lake went dry, tufa formed when a freshwater spring percolated from below and formed calcium carbonate deposits. When the lake's level dropped, these fragile formations surfaced, and wind went to work removing the sand beneath the deposits.

Persistent winds in the mountains of Nevada's Great Basin National Park eroded the trunk of this old pine tree into what look like a pair of sideways spectacles. The Great Basin hosts drastically varied climates, from its cold, snowy mountains to its dry, hot desert valley. S:\FACULTY\6th Science\Weathering and Erosion\weathering.asf

The Bernard Glacier in Alaska's Saint Elias Mountains looks like a huge alpine highway. Glaciers are slow but highly effective shapers of the land, essentially carrying away anything in their path—from soil and rocks to hills and even the sides of mountains. S:\FACULTY\6th Science\Weathering and Erosion\glaciers.asf

Heavy rains in northwest Iowa washed away soil, leaving this scarred tableau. This type of erosion, termed sheet-and-rill erosion, occurs when there is insufficient vegetation to hold soil in place. As rain falls, it forms sheets of surface water that transport soil away. As more water accumulates, it forms runoff channels called rills, which further displace soil.