This is an EarthCache so there is no physical cache to find. Instead, you need to send me the answers to the geology questions below via the message centre or e-mail before logging. Once sent please go ahead and log your find and I will get back to you if needed. If you are sending answers on behalf of others please state this in your message. Logs without answers may be deleted.
Questions.
1. How do organisms become fossils?
2. What type of rock are they found in?
3. Name two different fossils you can see in the ground/seating area slabs?
4. Post a photo of yourself/your geocaching name/a personal item at GZ without showing the fossils.
I was exploring Thetford having recently moved nearby and was surprised to notice these fossils, which were crying out for an earthcache of course 😀
FOSSILS.
There are two types of fossil, body fossils and trace fossils. Body fossils are plant and animal remains like teeth, shells and bones; trace fossils are things that an animal has left behind like footprints, burrows or poo.
It’s very rare for living things to become fossilised. Usually after most animals die their bodies just rot away and nothing is left behind. However, under certain special conditions, a fossil can form. They can form in a few different ways but usually an organism has to be buried very quickly in soft sediment such as mud or sand, in a calm, watery environment like a muddy sea floor, bottom of a lake or a river estuary. Over time this sediment builds up in layers and compacts, eventually becoming a sedimentary rock, like sandstone or limestone. Meanwhile, in a process called permineralization, the buried organisms remains are exposed to mineral-rich fluids that seep through the rock and replace the organic material with minerals like calcium carbonate or silica, becoming a fossil. This process can take millions of years.
Images of 10 fossils commonly found in the UK can be seen in the cache gallery, amongst them are Ammonites, Bivalves, Brachiopods, Corals, Gastropods and Trlobites.