Wednesday, January 26, 2011

Fossils at Gilbert?

Could it be? Have fossils been discovered at Gilbert? As much as I wish it were true, we didn't discover fossils as much as we created fossils.

Over the last week, we've learned lots of interesting facts about fossils. For instance, did you know most fossils are discovered in sedimentary rocks? Animals of long ago died. Their bodies decayed and were covered with dirt, bits of rock, or other sediment. As time passed, layers piled on top of layers, creating pressure and hardening into sedimentary rock. Thus, preserving the animals skeleton or bones. This type is called true form fossils. Of course we also found out that bones are not the only kind of fossil records to be found. The other types of fossils include mold, cast, imprint, and trace fossils. Feel free to ask any member of our class, we are eager to share our discoveries and research.

We decided to "dig a little deeper" into imprint fossils on Tuesday. Imprint fossils are formed from an organism moving in some way, leaving behind a trace or track. These tracks are preserved when the clay/silt dries slowly and is covered by other sediment. Plants can also leave imprint fossils when they are covered by sediment. The leaf tissue degrades, leaving an imprint of where the leaf once was. To create our own imprints, we used Crayola modeling clay and seashells collected from my trip to the beach during fall break. Here's a little peek...




Fossil Games & Websites

You put together the skeleton to various animals.
This site also has great interactive movies to teach you more about fossils.
This one is from National Geographic!