How does beach sediment vary along the coast between Lochranza and Catacol?

Authors Avatar

How does beach sediment vary along the coast between Lochranza and Catacol?

Hypothesis

For my investigation we studied a 550m stretch of beach between Lochranza and Catacol on the Isle of Arran, as shown on the OS map (page 2). On this beach it consisted of many granite and phylite pebbles. Phylite could have ended up here from erosion from the cliffs by abrasion. The granite however is not located in this area of the island and could only be transported by the River Eason, joining the River Charmadale and also the River Catacol. I think more likely though that the granite, which ended up on the beach we are studying, came from the River Catacol. When the granite is deposited at the river mouth they are all different sizes and we say that they are ‘unsorted’. This granite could have been transported round to the location where we studied by Longshore Drift travelling from the Southwest and transporting sediment along the coast towards the Northeast sorting the granite as it moved. There is evidence that longshore drift is acting and travelling from the Southwest direction. (1) It could have produced the spit located in Lochranza Bay and (2) the most dominant prevailing winds travel from that direction. For my investigation I am going to use Longshore Drift to produce 2 hypotheses:

  • Granite pebbles will become smaller in size towards Lochranza.
  • Granite pebbles will become more sorted towards Lochranza.

Development of a Strategy

To prove that this hypothesis is true, I needed primary and secondary data to help me. I was informed of what granite looked like so I knew what I was looking for (secondary). Geology maps were given to me also to be able to locate where the granite had come from (secondary). Another source of data was that a couple of days before we had studied river basins. This gave me some background knowledge to put towards my data collection and analysis theories. For the data collection we are going to walk along the beach and study the average size of the pebbles on that part of the beach. We will record the data in table and then analyse it, using standard deviation and spearmans rank correlation coefficient ( methods of numerical analysis) and present the data using different techniques, i.e. Scatter-graphs

Join now!

Before I undergo the data collection process I have to foresee a risk assessment as shown below: -

 

Data Collection

To gather the data we did an interrupted belt transept. We started at the end of the beach closest to Lochranza. We measured out 50m with a tape measure and took footsteps to see how many it would take for 50m so we did not have to measure it out everytime, although this is not very accurate. We started at 0m just below the strand line of the beach and continued along the ...

This is a preview of the whole essay