Explain why the sediment in windblown sand dunes is better sorted ...

[tichca]

Explain why the sediment in windblown sand dunes is better sorted than the sediment deposited by a flooding river.
 
  What will be an ideal response?

Question 2

Hard plastic bottles commonly used by hikers often contain the chemical
 
  A) BPA, which is a hormone mimic and may pose a health hazard.
  B) phenolphthalein, which has been clearly shown not to have significant health effects.
  C) PERC, which may result in minor skin rashes and other allergic reactions.
  D) PCBs, which may interfere with thyroid gland function.

[Dnite]

Answer to Question 1

Wind can only pick up a certain size fraction of particle sizes (roughly sand size). Therefore, wind-blown sand dunes are composed of sand-sized particles and are well sorted (particles are all of roughly the same size). In comparison to flood deposits, floods have more energy to pick up a large range of particle sizes and these deposits are poorly sorted.

Answer to Question 2

A