Station #3: Boulder and Tree


1)     Link to the following photos of the boulders located at Station #3.


2)     Sketch drawings for each photo in the space provided.

    The boulder contains both light and dark materials.The dark material is composed of chert.Be sure to show both materials in your drawing.



Top of Boulder                        ††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††††


Close up of solution channel


 Side of Boulder                      


Fossil in Boulder                     



3)     Perform an acid test on the hand sample from the boulder.Test both thechert (dark colored) and the lighter colored material.† †


††††† (a)Which of the following occurred on the chert?


____Acid bubbled right away with lots of bubbles


†††††††††† ____ Needed to be scratched with a knife/nail to get it to bubble, minor bubbling


†††††††††† ____Never bubbled


††††† (b)Which of the following occurred on the light colored material?


____Acid bubbled right away with lots of bubbles


†††††††††† ____ Needed to be scratched with a knife/nail to get it to bubble, minor bubbling


†††††††††† ____Never bubbled

4)     What do the results indicate about the composition of each of the materials?


5)     What do the results indicate about each materialís resistance to weathering?


6)     Read the following information on acid rain.


Use this information to give a detailed explanation for how the solution channels formed on the boulder.



7) Make several detailed observations of the tree (Sketch it here as viewed looking downstream):





Questions - Station 3

1) Give a detailed explanation for the formation of solution channels.




Visit the following sites to see an animation of cave formation:


-Flash Animation of Cave formation


-Flash Animation of Cave formation



2) How does your explanation for question 1 (above) and the animation, help to explain the formation of the many caves in this area?



3) (a) How is chert nodule formation similar to how stalactites are formed?



†††† (b) Using the boulder with the nodules, explain the concept of differential weathering.


Cephalopods are an ancient group that appeared some time in the late Cambrian period several million years before the first primitive fish began swimming in the ocean. Scientists believe that the ancestors of modern cephalopods (Subclass Coleoidea: octopus, squid, and cuttlefish) diverged from the primitive externally-shelled Nautiloidea (Nautilus) very early - perhaps in the Ordovician, some 438 million years ago. How long ago was this? To put this into perspective, this is before the first mammals appeared, before vertebrates invaded land and even before there were fish in the ocean and upright plants on land! Thus, nautilus is very different from modern cephalopods in terms of morphology and life history.



4)    (a) Identify the fossil in the boulder.



†††     †††(b) What does the fossil tell you about the environment in which the rock was formed?


 †††††     (c) What does this fossil tell you about the type of rock in which itís found?



5) (a) Why do the tree roots appear to grow out in mid air along the stream walls?



 †††††† (b) Why are some of these roots flattened?



6) List and describe the weathering and erosional processes that are taking place with the bedrock containing the tree roots in the table below.


Physical Weathering

Chemical Weathering

Erosional Processes