I was on a geocaching day trip in Dublin, when I noticed the fossils in this wall. There are some nice and really clear examples here, as well as some more unusual types of fossil.
How fossils are formed
Fossils are formed when a living organism dies and is buried by sediment. The body of the organism decomposes until only the skeleton is left. As more and more sediment builds up on top of it, the layers beneath are compacted into stone. The skeleton eventually dissolves from water seeping through the rock so there is a mould of it left behind. Minerals in the water fill the mould and crystalise, forming a fossil. The whole process occurs over millions of years.
Types of fossil
Here are some common types of fossil:
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1) Name some different types of fossils you can see in the wall.
2) What is the biggest one you can see? Name and describe it, including size (creative units welcome) and shape.
3) Include pictures of at least 2 different types of fossil in your log.
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