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Homework Help: Earth Science: Average Rate of Sediment Deposition

  1. Sep 27, 2011 #1
    1. The problem statement, all variables and given/known data

    Link of picture that the information below is referring to: http://i56.tinypic.com/283lv.jpg
    You encounter the sedimentary rock outcrop shown above while you are out hiking. You collect rock samples from points A-D and go back and measure their ages in your isotope lab.
    A=10.1251 million years old
    B=10.1259 million years old
    C=10.1262 million years old
    D=10.1278 million years old
    From detailed analyses of the rock textures and minerals found in the rocks, you determine that all of the rocks were formed from sediments deposited in a floodplain environment.

    A) Calculate the average rate of sediment deposition for the unit sampled by rocks A and B (show your work and give units):

    B) What is the average rate of sediment deposition for the unit sampled by rocks C and D (show your wok and give units):

    C) What changes in the local environment do you think might have caused this change in deposition rate?


    2. Relevant equations
    None that I know of.


    3. The attempt at a solution
    I don't know how to approach this problem at all.

    Thanks
     
    Last edited: Sep 28, 2011
  2. jcsd
  3. Sep 28, 2011 #2

    Borek

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    Staff: Mentor

    How is rate of sediment deposition defined?
     
  4. Sep 28, 2011 #3
    I'm not sure... that's all the information that's given.
     
  5. Sep 28, 2011 #4

    Borek

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    Staff: Mentor

    It should be defined in your books, or in your notes. If it is not - think, what IS rate of sediment deposition?
     
  6. Sep 28, 2011 #5
    A) Rock B-Rock A = #
    Take that #and 1.8/#
    Answer: .00225

    B) Rock D-Rock C = #
    Take that #and 2/#
    Answer: .00125

    That's what I think it is.
     
  7. Sep 29, 2011 #6

    Borek

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    Staff: Mentor

    0.00225 of what? Fathoms per fortnight? mph? Inches per year?
     
  8. Sep 29, 2011 #7
    meter/year
     
  9. Sep 29, 2011 #8

    Borek

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    Staff: Mentor

    Now it looks OK.
     
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