So why have I got you here looking at this cliff???
This area was once a Quarry and this exposed cliff face is a great place to see Sunderland's unique and world famous 'cannonball' limestone.
The rocky spheres or cannonballs as they are known locally are mineral growths called concretions.
The Magnesium Limestone seen here was formed 260 million years ago when Britain lay at a similar latitude to the present day Sahara Desert. It was deposited in a shallow inland sea called the Zechstein Sea. This sea stretched from here to Poland and the warm waters teemed with life. On the sea floor, layer upon layer of limy mud built up, eventually hardening into the limestone you see today
The concretions formed in the limestone after it was deposited and are made up of the mineral Calcite. They probably grew as a result of complex chemical reactions involving salt minerals in the shallow Zechstein Sea. How and why the concretions formed have baffled geologists for over a century.
To claim this earthcache please answer the following questions. You can send your answers to be via email or the geocaching messenging system.
1) Can you tell me where else in Sunderland you can see the cannonball limestone concretions?
2) There are good examples of the cannonballs at the base of the Jack Crawford Statue. Can you describe to me how they look and feel?
3) Can you tell me which Geological Period this limestone was formed in?
4) (Optional) Take a photo of yourself next to an example of the cannonball concretions or if you cannot find any, next to the strange door that leads into the cliff face.
***THERE IS NO REQUIREMENT TO CLIMB ON THE CLIFFS. PLEASE KEEP OFF***