AIM: DO NOW: HW:
AIM: PERIOD 1 AND 6: WHAT IS WEATHERING. DO NOW: 1 AIM: PERIOD 1 AND 6: WHAT IS WEATHERING? DO NOW: 1. DEFINE THE FOLLOWING TERMS: A. RESISTANT B. WEATHERING HW: WEATHERING TAKE HOME QUIZ DUE THURSDAY . YOU MUST PRINT IT OUT!
What do These 3 Things Have in Common?? Statue Grand Canyon Sand Pile
WEATHERING
The physical and chemical processes that change rock. What is Weathering? The physical and chemical processes that change rock.
For weathering to occur, rocks must be exposed to: AIR (atmosphere) WATER (hydrosphere) HUMAN AND/OR ANIMAL ACTIVITIES
Physical Weathering
What is Physical weathering? Rocks are broken into smaller pieces without changing the chemical nature of the rock.
Physical Weathering
Types of Physical Weathering
AIM: PERIOD 4 AND 9: WHAT ARE THE 2 TYPES OF WEATHERING. DO NOW: 1 AIM: PERIOD 4 AND 9: WHAT ARE THE 2 TYPES OF WEATHERING? DO NOW: 1. OPEN TO YOUR WEATHERING NOTES 2. WHICH MINERAL ON PAGE 16 IS MOST RESISTANT TO WEATHERING??? HW: WEATHERING TAKE HOME QUIZ DUE THURSDAY . YOU MUST PRINT IT OUT!
WHY DID THIS HAPPEN??
#1 Frost Action
Water seeps into cracks…. If it freezes it expands….. Slowly breaks (wedges) rock apart Cold and humid climates
Plant Action Tree roots grow into tiny cracks in bedrock….. As the roots grow and expand they break rock apart…. The roots continue to dig deeper and continue the process.
Tree roots can damage pavement
Abrasion
Water causes large angular sediments to tumble into each other…… The angular edges are chipped off….. The size of the rock decreases and it becomes rounded Common in running water “OR” Wind blows sand against bedrock…… Less resistant layers are chipped away and it becomes angular and pitted Wind abrasion in dry climates
ROUNDED ANGULAR AND PITTED
Humans!!!!
Cute little animals!!!
If you increase the surface area, you will ____________ the rate of weathering
WHAT VISUAL DIFFERENCE DO YOU SEE BETWEEN THE WEATHERED AND UNWEATHERED SHALE?
Chemical Weathering
What is Chemical Weathering? Rocks are broken AND the chemical composition is changed.
Types of Chemical Weathering:
Oxidation – Oxygen from air combines with minerals to form oxides = RUST
Red Sand has been oxidized
Oxidation of Statue of Liberty
Oxidation of Copper When copper oxidizes, it turns a greenish color – called patina.
AIM: WHAT IS WEATHERING AIM: WHAT IS WEATHERING ? (PART3) DO NOW: HW: WEATHERING TAKE HOME QUIZ DUE THIS THURSDAY
2. Carbonation Occurs when water containing carbonic acid dissolves minerals
Limestone Cave
What mineral in the limestone causes it to weather so easily What mineral in the limestone causes it to weather so easily? How do you know this?
Stalactites Stalagmites
3. Pollution Oxides of sulfur and nitrogen make rainwater unnaturally acidic. = Acid Rain
4. HYDRATION When water unites chemically with minerals Example: Hornblende + Feldspar + water = CLAY
Dominates in COLD, MOIST climates Physical Weathering: Dominates in COLD, MOIST climates
Dominates in WARM, MOIST climates Chemical Weathering: Dominates in WARM, MOIST climates
What do they both have in common? In general, when there is more MOISTURE, there is more weathering!
Shale Shale Shale Dolostone Which rock is the most resistant to weathering? Shale Limestone Sandstone Shale Sandstone Shale
Which rock is the least resistant to weathering? Shale Dolostone Which rock is the least resistant to weathering? Shale Limestone Sandstone Shale Sandstone Shale
What could affect the rate of weathering? (HINT: PAGE 16 OF THE ESRT)
Mineral composition Rock resistance (hardness)
What is the end product of weathering? Sediments
The end result of weathering and biologic activity is: SOIL
A B C D Soil Horizons: Bedrock Top Soil - Rotting plants (organic) & finely weathered rock A B Little organic material, partially weathered rock C Partially weathered bedrock D Bedrock
Transported & Residual Soil Types: Transported & Residual
Transported Soils: Carried (by wind, water, humans) from location of parent rock
Most of N.Y. soil is transported by: GLACIERS
Transported Soil
Residual Soil: Remains on top of bedrock from which it was formed.
Therefore, similar composition to bedrock below (parent rock)