Sideling Hill Road Cut

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					                                Sideling Hill
                                 Road Cut




 Sideling Hill is a
SYNCLINAL RIDGE

   It took about
350 million years
       to form!

When driving through the road cut… Think AFRICA!
          AFRICA?!!!
 SIDELING
HILL road cut




           AFRICA




            This is hard to understand using a current world map –
            but what if we could go back 200 million years?
                                       200 million years ago
                                            (Jurassic)




                                                       100 million years ago
                                                           (Cretaceous)




Record observations:
                                                                 Current
200 million years ago, Africa                                  (Holocene)
and North America were next to one
another! This is an HISTORIC example
of a convergent plate boundary.

What has changed about the
relative positions of North America
and Africa over the past 200 years?
What type of plate movement is this?
               The continental
               collision of North
               America and Africa
               resulted in the
               formation of the
               Appalachian
               Mountains and
               portions of the Atlas
               mountains.

               A current example of
               continental collision:
Appalachians
   Atlas       The Himalayas
 When Africa and North America collided 350 million years
    ago, the sedimentary rocks of our region folded!

   1. Initial arrangement    2. Compression     3.After collision:
   of sedimentary rocks




Folding animation
In animation, select ductile deformation with compression.
Click on action button below for a review of Rock Stress.

     To Rock Stress review                       To Move On
                         Rock Stress
                                               = sedimentary rock layers




           Compression



                                     Tension


   When rock is subjected to stress,
  brittle rocks would break (faulting)
and ductile rocks would bend (folding).            Shear

       Exploring Earth example
                        Rock Stress
                                               = sedimentary rock layers




          Compression



                                    Tension


Assuming we are dealing with ductile rocks,
  draw three diagrams to hypothesize what
                                                   Shear
would happen to these horizontal rock strata
     if subjected to these types of stress.

          Exploring Earth example
     Select ductile deformation to review
                        Rock Stress
                                               = sedimentary rock layers




         Compression



                                     Tension


 Assuming we are dealing with brittle rocks,
  draw three diagrams to hypothesize what
                                                   Shear
would happen to these horizontal rock strata
     if subjected to these types of stress.

         Exploring Earth example
     Select brittle deformation to review
• A SYNCLINE is a U-
  shaped downfold.
  Synclines initially
  form valleys. (smile)

• An ANTICLINE is an
  A-shaped upfold.
  Anticlines initially
  form ridges. (frown)
             What is Sideling Hill?




    Anticline OR Syncline?

       Ridge OR Valley?

Does this relationship make sense? How you explain a SYNCLINAL RIDGE?
 Draw a diagram showing the arrangement of rock
            strata within Sideling Hill.
       Highlight the meta-anthracite coal layer (the black layer)

• Your diagram should look something like this:
 When a syncline initially forms it is a valley with anticlines
                       on either side.
Extend the rock strata in your diagram to create two anticlines on either
                            side of Sideling Hill.
    Hint: Sideling Hill will now be the lowest point of your diagram.

Your diagram should look something like this:
                          Dashed lines represent
                          the Sideling Hill road cut




     Congratulations! You have just recreated the last 200 million years!
                     Erosion of Folds
Initial folding:




Following erosion:
• What is the view from
  the top of Sideling
  Hill?
• What would the view
  have been like 200
  million years ago?
         Is this the whole story?
The black layer (highlighted on your diagrams) is
             meta-anthracite coal.

                            • This is the eastern-most
                              coal in the U.S.
                            • For meta-anthracite coal
                              to form at least 7000 feet
                              of rock must be above
                              this layer.
                            • How does this information
                              alter your diagrams of
                              200 million years ago?

				
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posted:11/24/2011
language:English
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