To claim a find for this EarthCache you must visit the location given and make some observations. Then you must find the answers to the questions below and either email (for a quick reply) or use the geocaching message system, to send them to me.
I reply to email quickly and will endeavour to reply to the messages within a few days.
At the location given you will find a clock tower constructed in memory of local entrepreneurs and philanthropists Henry and Walter Whitehead. I have offset the geocache location a little because I didn't want it to be on top of the cache that's already here and to help you to be on the correct side of the monument.
This cache is about fossils, the main body of the memorial tower is made from Portland limestone, often called just Portland stone. This is a stone that was laid down on the floor of an ancient tropical sea where many, many creatures lived and died. As they fell to the floor of the sea the weight of more and more creatures compress and compact the material, over millions of years this process results in rock.
Fossils are the preserved remains of dead creatures, the process of these creatures being preserved is called fossilisation. It is very unusual for soft bodies of creatures to be preserved because these parts decompose quickly, but quite common for shells and bones to be preserved. Eventually the bones and shells start to dissolve and the fossilisation process starts and they are replaced by minerals leaving a replica of the original bone or shell called a fossil.
There are other fossilisation processes but the one above is the one we are concentrating on at this cache.
So having explained how fossilisation occurs the next stage of this cache is to identify the types of creatures that have been preserved here.
Here are two types of fossilised creatures you may find preserved in atropical sea.
Oysters
Oysters are a multi layered shell fish creature with a hard outer shell and a smaller flesh body on the inside. Generally with an adult oyster the shell will be the bulk of the oyster and the flesh only a small fraction of the total. Oysters is a common name for a few different families of salt or brackish water bivalves molluscs. They are irregular in shape and have a high calcium based shell. As The oyster grows it add more and more layers to its shell which means that if you were to cut an oyster shell it looks like many layers of paper. Since the major part of the animal is shell and this is more likely to be preserved it is common for stone to display shell fossils when cut.
When oyster shells are fossilised these layers are preserved and the cut stone cuts across the fossilised oyster shell it will look like many layers of paper or pastry in the stone. If the cut stone happens to cut along the dish of the shell an oval or irregular shape will be exposed.
Fish
Fish are the complete opposite to oysters with a flesh outer casing and an inner skeletal frame. With most fish the skeleton is the smaller fraction of the body weight and he flesh the higher proportion. Fish and swimming mammals are a huge family of creatures and very common fossils however with the smaller fraction being the parts that tend to be preserved, many more fish fossils are needed to create stone.
When stone is cut that contains fish skeletons it is less likely to see many skeletons because they are less frequent in the rock itself. If a cut is along the length of a fish then a fossil is likely to be seen but if the cut is across the body of the fish it would be difficult to see.
Questions
To answer the questions below you will need to be on the Manchester road side of the clock, on the left as you approach from the gardens.
About 8 feet above the platform there is a protruding horizontal band around the tower, this is called a DADO rail and is for decoration. Some of the features I'd like you to find are above or below this so I thought I'd just explain what it is.
I would like you to look up at the rock face, just above the dado band (though one of the best fossils is just below it)
You are looking for small fossils which protrude from the smooth rock surface.
1) Look above the dado, and feel the rock below, please describe the stone face, with reference to the colour, smoothness and small protrusions.
2) Below the dado, describe the one large fossil and give me it's approximate width and height.
3) What type of fossils are preserved in the stone, please tell me what evidence you used to reach your answer.
Thanks for attempting this cache
treboR