Saundersfoot beach intrusion EarthCache

An EarthCache which requires you to visit the location given, make some observations and answer some questions.

To log a find please either email or message the answers to me, you may do this and log your find at the same time.

There is plenty of parking on the town car park but you will have to pay.

This beach is wheel accessible but the sand may be too soft for wheelchairs.

Please check the tide times, this cache may not be accessible at high tide.

 Please focus your attention on the large wall type structure that extrudes out onto the beach

. Sedimentation

  When a river flows through a valley it will take with it small particles of rock worn from the faces and surfaces it passes over. This process is called erosion and is one way how new rock is made. The new particles are carried downstream The faster the flow the more particles the river can carry. As the water flow slows these particles are deposited on the bed of the river, this is called settling .

 Over an extended period of time, which could be millennia, this depositing of particles forms layers, these layers build up and the pressure from above compacts the deposits, forcing the water out and rock is formed.

  If the river flows into a delta the process of depositing the rock fragments can create vast swaths of deposit, which would be of similar hardness when it forms rock. This would form huge sheets of similar rock, which can be quarried. Evidence of this type of deposit is easy to find in many quarries across the country.

  Another scenario however would be where a river carrying rock fragments flows into a pool or lake slowing the water flow sufficiently to deposit the particles before it then flows on. In this situation a rock formation could be formed that is much smaller than the delta example and the rock formed would be quite localized forming an effectively vertical formation. The pressing and compaction of the rock above would still happen but instead of forming a large wide block of rock a 'wall like' formation could be created.

Think about the way water flow might have varied in each type of environment to help in answering question 2 below.

 Erosion

 Erosion is the process by which soil and rock particles are worn away and moved elsewhere by wind, water or ice. Erosion will move the small particles that the wind or water can carry away to different location, leaving behind rounded rock surfaces. Erosion will move the easiest particles first. Water is the main contributor to erosion since it can carry more particles than wind.

 At this location the rock has suffered erosion and this can be seen because the rocks are rounded with the some surfaces rounded and some cupped. As the wind, rain and sea has battered these rocks it has broken off small particles of the slightly softer rock and left behind the harder core of the rock. .

 At this location the main contributor to the erosion of this intrusion onto the beach has been the sea. Each day as the tide comes into the base of this rock intrusion the action of the water will wear away small particles and carry them away.

Time to answer some questions.

Questions

1. Please describe the features of this intrusion onto the beach, concentrate on the texture and shape of the rock and how far it extends from the 'prom'.
2. Please tell me why this intrusion is here, giving reasons for your conclusion.
3. Please explain what type of environment might have been present as this rock was laid down.
4. Now explain why this intrusion does not extend further across the beach and explain what brought you to this conclusion
5. There is a hardy tree on the top of the feature; including the tree approximately how tall is the tallest part?

If you feel willing and able please include a photo but not from too far away since that might give answers away.

Thanks for visiting the area and I look forward to reading your logs.