Year 3 Rocks topic - practical activity showing how fossils are formed

Hello everyone

I hope you are all well. I am currently planning the Rocks topic for Year 3. I am using PLAN exemplification resources as a guide and there is a really nice activity showing how to fossils are formed using plasticine, shredded kitchen roll paper and dog biscuits, among other things. I have been trying to find a resource online that gives a step-by-step guide on how to do it but I cannot seem to find anything. I am just wondering if anyone knows about this and could point me in the direction of a resource?

Many thanks,



Subject(s)Science, Earth science, Practical work, Techniques and procedures, Demonstrations
Report inappropriate content 


Sign in to post comments

Sarah Dagnell

Hi James,

I'm afraid I can't find a step by step instruction for that activity either.  However, the comments in black on the PLAN Assessment PowerPoint do pretty much give them.

1. Flatten some Plasticine on the bottom of a small pot to make the sea bed.

2. Add a bone shaped dog biscuit to represent a creature which has died and fallen to the bottom of the sea.

3. In a separate container, mix together lots of salt, water and blue food colouring to make the sea.

4. Shred lots of kitchen roll to represent the sediment (shells, bits of rocks etc).

5. Add some sea to the sea bed and then add the kitchen roll sediment.

6. Put on a pair of plastic gloves, then push this down to represent the pressure building up.  Add more and more sediment, continuing to press it down until all of the sea has been absorbed. You could keep adding sediment to observe the different coloured layers.

7. Like an archaeologist, unearth fossils from the sediment using a tooth pick.

8. Examine the fossil imprints and fossilised bones.

I hope that helps, Sarah 


I've tried it as well but more edible foods they can eat or try so only using foods. Did this probably more for sedimental sandwiches but guess the idea could work as well.

I also used bread & other layers (jam, crushed biscuuits, peas, choc chips), children squashing 'pressue' as they go along and then they can discover but also eat it. Friday afternoon worked out well 

Hope that helps


Hi James

Doesn't answer your specific question but I came across this website for Science CPD the other day. It has some good stuff on it