Weathering Mechanics
What type of weathering causes physical changes to a rock without changing its chemical composition?
Physical (or Mechanical) Weathering
What is the movement of sediment by agents like water, wind, ice, or snow?
Erosion
What is the process of dropping or laying down sediment in a new location?
Deposition
What is soil composed of?
A mixture of rocks, minerals, organic material, water, and air
What dark-colored material in soil forms from decomposed plant and animal remains
Humus
What type of chemical weathering occurs when oxygen reacts with minerals like iron in rocks?
Oxidation
What agents can carry broken-down pieces of sediment from one location to another?
Water, wind, ice, rain, or snow
Before sediment can be depositied in a new place, what two process must happen first?
Weathering & Erosion
What layer of soil consists of solid, unweathered rock at the very bottom of the soil profile
R Horizon (Bedrock)
How do earthworms help make soil healthy and fertile?
They breakdown organic matter into humus and burrow/mix the soil
What part of a plant can grow and crack rocks, pushing them apart as they expand?
Plant Roots
What single force powers events like landslides, mudslides, & the rolling of boulders by pulling large amounts of soil and rock down a slope?
Gravity
When a windstorm or river slows down, what happens to the sediment it is carrying?
It drops/settles (deposited)
The texture of soil depends on________
Particle Size
Which layer of soil determines the soils pH?
Parent Material; Horizon C
What process describes the grinding or wearing away of rock by other rock particles carried in water, ice, or wind?
Abrasion
Out of lakes, ponds, rivers, and ocean waves, which agent erodes coastal landforms the fastest because of its strong force?
Ocean Waves
When a fast moving river carrying heavy sand, lightweight silt, and medium weight clay suddenly slows down, in what order will these sediments be deposited
1st-Sand (heaviest)
2nd-Clay
3rd-Silt (lightest)
Layers of soil are called____________
Horizons
How does planting a line of trees along the border of an open, windy farm field protect the topsoil?
The trees act as a windbreak (or wind barrier) that blocks high winds from blowing away dry topsoil
If a single large boulder and a pile of small pebbles made of the same rock type are exposed to rain, which will weather faster?
The pile of small pebbles
Breaking rock into smaller pieces increases its surface area, exposing more of the rock to weathering agents
Why do crashing ocean waves erode coastal cliffs significantly faster than water in a lake or calm river?
Because ocean waves hit with great force, breaking rocks apart and carrying abrasive sand/sediment that accelerate physical erosion
Why does weathering and erosion always have occur BEFORE deposition can happen?
Because rocks must be first broken into sediments (weathering) and transported to a new place (erosion) before that sediment can finally settle or drop (deposition)
What is the correct letter order of soil horizons from top to bottom?
What factor can scientist look at about the soil to determine its fertility?
Color