Welcome to the Zebra Rock sculpture in Cobtree zoo.
Zebra Rock is an unusual sculpture consisting of two contrasting limestones, black and white, hence giving the sculpture the name, Zebra Rock. The two stones used are white Portland limestone, and black Kilkenny limestone (also known as Kilkenny marble). The base and three stripes of the structure is in the Kilkenny limestone and two bands are in the Portland limestone.
This EarthCache will ask you about what you can see within the stone... FOSSILS!
Kilkenny Limestone
Kilkenny limestone is a Carboniferous limestone containing fossils. The rocks formed around 365-325 million years ago. It was formed in warm, shallow seas which was filled with life. The rock is made up of the shells and hard parts of millions of creatures. Corals, brachiopods and crinoids are within the rock and you will see that the rock is full of fossils.
Portland Limestone
Portland limestone is a calcium carbonate limestone and is softer than the Kilkenny limestone. This rock formed during the Jurassic period approximately 145-150 million years ago. This Portland limestone has less fossils than the Kilkenny, but there are still fossils within.
Questions
Look closely at the stripes and describe what you can see. You may like to include measurements, shapes, textures and colours that you can see.
1. Please describe the Kilkenny (black) limestone. Please describe the colour and texture of stone, colour of fossils, amount of fossils, spacing of fossils.
2. Pick a couple of the fossils and describe their sizes and shapes.
3. Are all the fossils the same?
4. Please describe the Portland (white) limestone. Please describe the colour and texture of stone, colour of fossils, amount of fossils, spacing of fossils.
5. Pick a couple of the fossils and describe their sizes and shapes.
6. Are all the fossils the same?
7. Are the fossils more numerous in the black Kilkenny limestone or in the white Portland limestone?
8. Optional photos or selfies of the sculpture are welcome. But please not any close up shots of the rock which would reveal the answers.
Hope you enjoy this EarthCache.
