Apologia General Science, Module 7, The Fossil Record

►Videos and Resources for M7

Fossils, fossils, fossils!  There are many different kinds, and many of them do not contain actual matter from the original fossil!  Such is the case with cast fossils.

Casts and Molds
We used homemade playdough (directions) to make molds with the items the kids brought to class (use a little smear of vaseline to keep from sticking), then poured in plaster of Paris to make fossil casts.

The lego mold was a little warped, causing the fossil cast to be a little warped.  =)

The cast will always be the shape of the mold.  So if a clam gets buried by sediment, after the soft tissue decays and sediment settles and hardens around the clam shell, if the clam shell eventually weathers away and the mold is filled with more sediment, that is what kind of fossil cast a paleontologist might find one day.

(I do not like blank spaces!  So I am writing something to fill it in..... blah, blah, blah!)
LOL!




Petrifaction
We made a petrified log!  Kind of.  =)
Actually, a real petrified log comes from when mineral-laden water seeps through a log and hardens there, and as the log decays, the minerals stay, eventually totally replacing the log!  Minerals are what rocks are made of, so the result is a large, log-shaped rock!
If you were too scared to move, you might say you were turned to stone, or petrified!
We mixed Epsom salts with water and laid our paper towel "log" in the mixture and rolled it over so that all sides were wet. (directions)  We kept in in the sun for two weeks so that it would dry and harden from the minerals.  This is like a petrified log in that there are minerals in it, but unlike a petrified log in that the original materials (paper towel) remained.
Then we tried to burn it.
Petrified anything will not burn!
Just watch:

We also tried to get a Carbon Residue or Impression by placing a green leaf between two sheets of paper, and applying pressure.  I demonstrated in class by weighing a 2-gallon water cooler that we were going to place on the leaves.  It weighed 17 pounds!  Much more than the book required, so I figured we'd get a good result.  We placed the leaves between the sheets of paper, then placed those between two very flat boards and the water cooler on top.  We did not move it for 3 weeks, but still we only had a slight impression, and a very faint green color where the stem was.
Well, my niece and nephew had placed theirs under 2 large bags of concrete -- 160 pounds!  Theirs was the only good results.

Other kids only used a few books or other similar weight as called for, but there were no results.  Literally.
Their papers looked like... nothing.  =\
 I think I'll try this one again, and just leave it there a little longer.
(Similar directions to what we used - but they suggested a fall leaf.)

We also learned about Remains in Ice and Remains in Amber.
At the beginning of class, I showed the class a frozen chunk of ice in a bowl, and placed a rock on top of it and put it back in the freezer.  At the end of class, the rock had sank down in the ice a little and was frozen there.  This is one idea of how animals become entrapped in ice.  Um... idk if this is right, because large animals can take 5 days to totally freeze all the way through and their insides would be rotting by then.
If an animal were actually buried quickly by snow and ice, then it would freeze quickly, preserving much of its remains.

For the insects trapped in amber, I came across a neat idea of using orange jello with insects inside.
I just knew this would be a hit.  I heard ewwww! from several girls, even though I had washed the li'l buggies beforehand.  [innocent voice]  =D
The only insects I could find were bigger than I was expecting, so I used 2 packages of jello to cover the insects for 8 treats.  Some wanted to float up out of the jello, so I used forks on those, precariously perched, holding down antennae or legs, lol.  I did remove the forks before the jello got too firm.
I did see a few girls take a taste or two, but most was left uneaten.  lol.

This module was mostly about the fossil "record," so we did learn about fossils.
We also learned more about the uniformitarianists' view and the catastrophists' view of how the geography of the earth came to be the way it is.
But we also learned four very important features of the fossil "record."
1.  Fossils are usually found in sedimentary rock.  Sedimentary rock is washed and laid down by water.  (Does that tell you something about the Flood?)
2.  About 95% of the fossils found are clams and other hard-shelled creatures - not wooly mammoths or other large animals.
3.  Many of the fossils that are found are of plants and animals that are still alive today.  So... nothing changed from "billions" of years ago to today!  =)
4.  Different kinds of fossils can be found in two of the same kind of layers of stratified rock.  This shows that layers of the same kind of rock do not represent time periods of different fossils.

sMiLeS,