Weathering, Erosion and Deposition7.8B analyze the effect of weathering, erosion and deposition on the environment in Ecoregions of Texas
Video!
• Crash Course on Weathering, Erosion and Deposition
Key Terms (cont’d):
CHEMICAL WEATHERING
THE PROCESS THAT BREAKS DOWN ROCKS BY CHEMICAL CHANGES OR REACTIONS.
This statue has lost finer details in the eyes and lost major details of the nose
MECHANICAL WEATHERINGTHE PROCESS THAT BREAKS DOWN ROCKS BY PHYSICAL MEANS (NO CHANGE IN THE CHEMICAL NATURE OF THE ROCKS).
Grand Canyon is an example of mechanical weathering
Fill in your chart (mechanical)Type of Mechanical Weathering Explanation
Ice Wedging Process that splits rock when water seeps into cracks, then freezes and expands
Exfoliation Extreme high temperatures cause the outside of rocks to crack and flake off
Root Pry Roots enter cracks in rocks, forcing the cracks further apart
Actions of Animals Burrowing in the ground breaks rocks apart
Abrasion Grinding away of rock by other rock particles
Fill in your chart (chemical)Type of Chemical
WeatheringExplanation
Water Water weathers rock by dissolving it
Oxidation Rocks that contain iron, oxidize (rust) and appear red in color
Carbonation Carbon dioxide and water mix to form carbonic acid – over time caves form
Living Organisms Plants produce a weak acid that dissolves rock
Acid Rain Pollutants react chemically with water vapor to form acid rain
Key Terms:
Weathering – chemical and physical break down of rocks into sediment
Erosion – the movement of sediment from one place to another
Deposition – the placement of sediment after being carried from place of origin
Erosion
• First picture - The water weathers the rock and then carries it away from its original location
• Second picture - Utah Canyonlands are created by the wind carrying away rock particles
DepositionExamples:
1. Deposition of this sediment occurs when the waters slows down and the heavier particles drop, forming a delta
2. The sand dunes were created when particles carried on wind were dropped in a new location
Weathering Erosion and Deposition Lab
Do you have your lab page?
This lab will demonstrate different types of weathering, erosion and deposition.
Follow the instructions both on the lab page and at each station. CLEAN UP IS REQUIRED!
Questions at the end are required as part of the reflection and understanding of this lab.
MAKING OBSERVATIONS
What tools do you use to make good observations?
How do you describe observations?
Use descriptive words, for example: don’t just say “white”, say “white with a powdery surface that easily comes off on my hand”.
Lab Stations 1-3
Stations need to look like this BEFORE your time is up at this station.
DO NOT be the group that holds everyone else up!
You MAY NOT leave your station to rotate to the next one if your current station is not clean!
Work in your table groups
• Start at the station you are assigned. When the timer goes off, move to the next station in numerical order.
http://www.online-stopwatch.com/