What are the 2 types of weathering?
What is erosion?
the transportation of weathered sediment by water, wind or ice. Water being the most important agent.
What are the 3 main forms of Mechanical Weathering?
- Frost Wedging
- Sheeting(exfoliation, unloading)
- Root Wedging
What is Mechanical Weathering?
also called physical weathering, it is breaking down the rock into smaller pieces.
What is Chemical Weathering?
when rock materials are decomposed by chemical alterations.
What are the 3 ways Chemical weathering occurs?
- Solution or Dissolution-dissolving by water and carbonic acid(rock salt,gypson,and limestone)
- Hydrolysis-formation of a new material from the original material(granite)(most imortant)
- Oxidation-combining oxygen with mineral"desert varnish"
3 factors that effect the rate at wich weathering occurs
- Composition-olivine least resistant, quartz most resistant
- Climate-humid is high, desert and snow is low
- Amount of surface area exposed-spheroidal weathering
What are Joints?
fractures along which no displacement has occurred
What is regolith
the top blanket of the earths surface(Soil)
3 facts of sedimentary rocks
- contain economically important minerals
- contains a record of history(fossils)
- makes up 70% of surface rocks
How are Sedimentary rocks made?
- Sedimentary Differentiation(sorting by wind is most effective)
- Cementation and Compaction(lithification)
what are sedimentary rocks?
Composed of fragments of other rocks, or chemical precipitates or organic material
2 groups of sedimentary rocks
- Detrital-consists of rock fragments
- Chemical-consists of precipates and organic material
4 classes of detrital rocks
- shale(most abundant
5 classes of precipates
- Rock salt
How are sedimentary rocks classified
- Detrital by size and shape of fragments
- Chemical by composition