WARM UP Write in your notebook for today’s date that the warm up was the quiz Take out your foldable and a pen or pencil.

Weathering of Rocks 2 main types of weathering Mechanical weathering requires physical forces to break rocks into smaller pieces. Chemical weathering requires the transformation of rock into one or more new compounds.

Mechanical Weathering – Frost Action water forces its way into the cracks water freezes which causes the crack to expand more water fills the cracks and freezes rocks split apart

Mechanical Weathering –Exfoliation rocks are uplifted and the rock surface is eroded away dome shaped rock outer edges are cracked and break loose – exfoliation.

Mechanical Weathering –Landslide & Abrasion Mass movement of rocks and soil down a slope Abrasion Wearing away of rocks by solid particles carried by wind water or other forces

Mechanical Weathering – Biological Activity animals burrow through the rock Root Pry – plant grows in the crack of a rock making it larger

Chemical Weathering – Water Most important agent of chemical weathering dissolves various gases from the atmosphere and soil causes a reaction with minerals in the rocks

Chemical Weathering Oxidation: Carbonation: Oxygen reacts with the metals in the rocks to produce oxide (rust) to create a yellow to reddish-brown rocks Carbonation: Carbonic acid (CO2 + H2O) dissolves away the surface of the rocks

Rate of Weathering Rock characteristics - granite rocks are more resistant to weathering while marble (calcium carbonate) dissolves easily with acid rain Softer minerals will wear away quicker leaving peaks and holes in the rock structures Areas with more cracks will break apart more quickly

Rate of Weathering Climate Temperate climates have greater frost wedging and chemical weathering Influences the types of vegetation that grows in the area Dry, arid climates and polar climates have slow weathering of rocks

Rate of Weathering Physical Weathering INCREASES surface area MORE CHEMICAL WEATHERING CAN OCCUR

Mass Movement Rock Slides (landslides) Rock Falls Slumps Mudflows Earthflow Creep http://player.discoveryeducation.com/index.cfm?guidAssetId=f3e2749c-d871-4eba-930f-f30574a4cf79# http://www.youtube.com/watch?v=mknStAMia0Q&feature=player_embedded

Rockfalls What type of weathering has taken place to cause this mass movement? Explain how this mass movement happened.

Rockslides A block of material moves suddenly along a flat, inclined surface Among the fastest mass movements Can be over 200 km/hour Mostly triggered by rain or melting snow

Mud flow Moves very quickly downhill Similar to concrete- contains silt and clay. Common in California

Earth Flow Slower than a mudflow Marked by a “Scarp” in the land at the top of the elevation and a “Toe” at the bottom.

Slump Leaves a crescent shape cliff at the top marked by a layers of soil that seemed to fall straight down.

These are both drawing of very slow mass movements called Creep These are both drawing of very slow mass movements called Creep. Leaning trees and cracked roads are evidence this mass movement has taken place.

I-40 Rockslide

1997 I-40 Rockslide

What mass movement is this?

Based on the events in the diagram, what mass movement is being illustrated here?