Weathering: breaking down of rocks, soil and minerals as well as artificial materials through contact with the Earth's atmosphere, organisms and water.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Slide 1
Slide 2
Slide 3
Weathering: breaking down of rocks, soil and minerals as well
as artificial materials through contact with the Earth's
atmosphere, organisms and water. Two basic types
Physical/mechanical Chemical
Slide 4
Frost/Ice wedging Water seeps into open spaces and freezes.
Expansion of water wedges and cracks material Breaks at distinct
angles
Slide 5
Exfoliation also known as unloading, overlying materials (not
necessarily rocks) are removed (by erosion, or other processes)
which causes underlying rocks to expand and fracture parallel to
the surface
Slide 6
Plant roots seedlings sprouting in a crevice and plant roots
exert physical pressure Provide a pathway for water and chemical
infiltration. Paper beats rock
Slide 7
Abrasion mechanical scraping of a rock surface by friction
between rocks and moving particles during their transport by wind,
glacier, waves, gravity, running water or erosion. moving particles
dislodge loose and weak debris from the side of the rock.
Slide 8
Clicker Which type of Physical weathering occurred in the
picture below? a)Frost/ice wedging b)abrasion c)Exfoliation d)Plant
roots Timer Times up!
Slide 9
Oxidation: Materials react with Oxygen from atmosphere or water
(H 2 O) Most common Iron (Fe) rusting
Slide 10
Hydrolysis(water): Materials react with water to form new
material Water dissolves rock Chemicals in water react
Slide 11
Dissolution: Acid dissolved in water dissolves rock Reactions
carbon dioxide + water carbonic acid CO 2 + H 2 O H 2 CO 3 carbonic
acid + calcium carbonate calcium bicarbonate H 2 CO 3 + CaCO 3
Ca(HCO 3 ) 2
Slide 12
Plant Acids: Some plants produce weak acids that seep into
rocks and dissolve certain minerals Examples : Lichens and
Mosses
Slide 13
Question What type of chemical weathering process produces
corrosion and iron oxide? Oxidation Timer Times up!
Slide 14
ROCK COMPOSITIONCLIMATE Rocks are made of minerals Tougher the
mineral the slower the weathering Surface area More area exposed to
weathering forces, faster the weathering Very cold( no change) Slow
weathering Polar regions Dry and Hot Slow weathering Desert regions
Moderate (warm summer/cold winter) Fast weathering Temperate
regions
Slide 15
Slide 16
Slide 17
Clicker While doing a standard pH test on uncontaminated rain
water, you observe a pH of 5, this result indicates that: a)Rain
water is slightly more basic/alkaline b)Rain water is neutral c)You
made an error d)Rain water is acidic Timer Times up!
Slide 18
pH concentration power of Hydrogen Lower pH = more H+ ion
(acidic) Higher pH= less H+ more OH- ion (basic or alkaline) 1 x 10
pH =Concentration
Slide 19
1 x 10 -2.5 =.003 1 x 10 -6.5 =.0000003.003/.0000003= 10000
times more concentrated Or 6.5-2.5=4 10 4 =10000
Slide 20
Bedrock: Solid un-weathered rock below the surface Regolith:
layer of loose, weathered material covering solid
rock.(bedrock)
Slide 21
Minerals 54% weathered rock Rocks are made of minerals Water
25% water Gases 25% Air Humus (organic matter): 5% organic
material
Slide 22
Explain the relationship between weathering and soil formation.
Weathering and erosion make soil
Slide 23
Soil profile: Cross section, shows layers top to bottom O.
Organic materials A. Topsoil (organic material) B. Subsoil minerals
collect C. Regolith R. bedrock
Slide 24
Clicker Soil is formed as a result of which of the following:
a)Weathering of rocks and minerals b)Decaying of plants and animals
c)Microorganisms adding Nitrogen d)All of the above Timer Times
up!
Slide 25
Slide 26
Tropical climate: Rain and High temperatures cause thick
infertile soils to develop. Desert: Low precipitation causes thin
soil Arctic: Slow weathering creates thin soil