Lecture 6 Flashcards
What element is most susceptible to oxidation?
Iron
What are the 3 types of weathering?
Physical, chemical, and biological.
Which minerals are best at surviving weathering?
Minerals formed at lower temperatures. (they are hard and no strong cleavage planes)
What is weathering?
A process that changes the surface material of the earth.
What is erosion?
The removal of material from one position on the surface of the earth to another position.
What is physical weathering?
The mechanical fragmentation of rocks and minerals.
What is the strength of bonds between atoms dependent on?
Pressure and temperature
What are the 3 agents of erosion?
Water/ice, wind, and gravity
what are the 7 types of physical weathering?
frost action, abrasion, pressure release, hydraulic action, salt crystals (evaporation), insolation, slaking
What is frost action?
water, or ice, expands as it gets colder (4°C -20°C)
What is abrasion?
refers to the breaking and grinding away of solid rock by collisions with moving particles
What is pressure release?
when rocks deep in earths crust move upwards, pressure decreases which allows them to expand causing fractures
What is hydraulic action?
waves force water into cracks in rock, air is trapped and compressed, water recedes and compressed air is released explosively
what is salt crystal weathering?
sea water enters into fractures, as water evaporates crystals form, when heated crystals can expand
What is insolation weathering?
due to repeated heating and cooling of rocks
Slaking?
The disintegration of rocks undergoing cycles of wetting and drying
What are the 3 types of chemical weathering?
Hydrolysis, oxidation, dissolution
Is mass wasting erosion or weathering?
erosion
what is hydrolysis?
splitting up with water (the elements of water are added to the resulting molecular fragment)
What is oxidation?
Oxygen steals an electron
What is dissolution?
When exposed to water, ions stick to water and are dissolved
Biological weathering can be either or both chemical and physical
true
How are chemical sediments formed?
from materials dissolved in water
What are reduction spots caused by.
Oxidation
