Saddle Rock or Greymare Rock is located in the rocky bay just north of Dunstanburgh Castle. It is made up of a series of stone "beds" projecting out into the sea through a jumble of dolerite boulders. The twisted, wave-like "Whale Back" fold in the rock was created by pressure and heat - forces within the rock compressed and folded the structure giving the saddle / wave like appearance or what might look like a cross section through a mini volcano when viewed from the side. The wave-like shape is believed to give this feature it’s name since it appears that one of the white horse wave crests has solidified on the land.
The rock formations in this area are of national importance and Greymare Rock was identified as part of the Geological Society's 100 Great Geosites in 2014. Visitors to the site can see the layers of limestone, mudstone and shale, stacked up in a permanent record of the rising and falling tropical seas that once covered this area - the upper surface of each layer was once the top of the sea bed. The layers of the Rock appear more prominent as "softer" layers of rock such as mudstone have eroded over time, appearing to leave gaps between the layers of limestone.
To log this Earthcache, please send a message to me with answers to the following questions, logs submitted without answers being sent will be deleted.
1. Standing facing North (towards the rock) estimate how many metres high the top of the "Saddle" stands above the beach.
2. How many layers can you count in the upper section?
3. Describe the texture of the upper surface of the rock. Can you suggest a reason for this texture?
4. There are white markings in the rock which, from a distance, might appear to be bird droppings. Have a close look and describe what the markings are - can you name the material they're made of?
5. How many "Whale Back" humps can you spot in the area?
6. (Optional) Take a picture of yourself / your device at the location and submit this with your log after I've confirmed that your answers are correct.