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If you would like to add more caches to this series, please feel free to do so!
Please contact heartradio through his profile first so that he can keep track of numbers and avoid duplications. Caches should be any type except Traditionals, so cachers can learn more about the beach
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This EarthCache is located on one of the most secluded beaches, with the exception of the other visitors, that is only accessible via water, or the smugglers tunnel. This tunnel, despite its name, has not seen any such goings on as it was instead commissioned in the 1860's by the 8th Lord Clifford to give access to the beach below. At the top of this tunnel, near the trailhead, there is a limekiln, that probably dates to a similar period.
Sand can mean different things to different people. To beach lovers it is the staple of a sunny day spent building sand castles, swimming, amounts other activities. To others it is an annoying substance that manages to magically get into everything and will be found in bags for months to come. On a more scientific level sand is a term that defines a size of particle, between gravel and silt, measuring 2 mm - 62.5 µm. As well as this sand can also be a useful indicator on the local geology and geomorphological processes, such as long shore drift.
Sand is one of the most iconic features of any beach, and Ness Cove is no exception. But what many of the beach goers don’t stop to consider is how the material forming the beach, either sand or other, is created and what it can indicate about the geology of the area and the conditions that the material has been exposed to.
As rock is exposed to the processes of erosion, be it water, ice, biological or other, it tends to break down in size. This could range in size from the size of a pebble, or even smaller, all the way up to great boulders, especially common in cliff falls. After the material has been separated from the main unit of rock, it continues to be weathered, and so it continuous to get smaller in size, eventually resulting in sand sized particles. The rock will likely go through multiple types of erosion, depending on its location and the type of rock. Once the rock forms part of the beach material the single biggest type of erosion that it is subjected to, and continues to shape the material, is attrition. This is where pebbles and sand are bumped together causing them to break down and wear each other down over time. Sand is largely made up of sand sized pieces of rock, often mixed with some small gravel sized pieces and shells.
The age and environment that the sand particles currently reside in can have an obvious effect on the shape and appearance of the sand grains. For example in environments where the sand is exposed to rougher seas they smash and grind against each other. This results in sand grains that are rounder and smoother than those that are in more sheltered locations. Similarly the longer that the material has been exposed to weathering the more effect it will have on the shape of the sand. In locations where the sand is 'younger' or not exposed to so much weathering processes, then the sand grains are more angular.
Because the composition of the sand sized rock particles found in sand are entirely based on the rock that they have been weathered down from, they can be diagnostic as to the location where beach material may have formed. Indeed this results in beaches around the world having very different coloured sand, solely based on the geology from which the main component of the sand is from.
Examples of this can be seen from around the world. At Punalu’u Beach in Hawaii the sand is a striking black colour. This is because in this region the geology is primarily Basalt.
Also in Hawaii, at Papakōlea Beach, is one of the rarest coloured beaches, green. Green sand (not to be confused with the rock type) is comprised of olivine crystals that erode out of the local Basalt geology. Because the crystals are heavier than most of the other components that form sand in the area the crystals remain on the beaches after the lighter sand grains are washed away.
At Hyams Beach in New South Wales, Australia, the sand is in the Guinness Book of World Records as being the whitest anywhere in the world. This is because they are made from particles of quartz from the local geology.
At Ramla il-Hamra, on the Maltese island of Gozo, there is orange coloured sand. The area is highly volcanic, and this has partly resulted in these wonderfully coloured beaches. Material from the volcanic activity and the unusual orange limestone that is found in this area combine to create the orange sand.
The yellow/tan colour of sand that most people will be familiar with is often a result of a combination of different coloured particles that give an overall impression of this yellow/tan. Although the beach at Ness Cove is not as impressive, or potentially inviting, as those listed above, it too tells a story about the location that the material forming the sand.
The cliffs at Ness Cove, which is representative of the geology of the area, are very impressive, especially when you exit the tunnel to see them. These cliffs are largely comprised of Breccia, which is a sedimentary rock type that is common in Devon, especially around the Exe Estuary and along the coast down to Torbay. Breccia is a sedimentary rock comprised of angular fragments of rock (over 2mm in diameter) that are cemented together by a matrix. This matrix can either be comprised of the same or different types of components to that of the larger fragments. Breccia is very similar to conglomerates, such as Puddingstone. The main difference between the two is the shape of the particles. Breccia is made up of angular fragments, where as conglomerates are made up of rounded fragments, that have commonly been rounded by water action.
To log this EarthCache go to the posted coordinates and send me a message or email answering these following questions
1) Look at the sand on the beach and describe its appearance, including the various coloured material that you can see.
2) Based on your previous answer what conclusions could you draw about the age/conditions of the sand at Ness Cove?
3) Look at the cliffs surrounding the tunnel and describe the appearance of the Breccia rock.
4) When you look at the base of the cliff can you see any evidence for the erosion of the cliffs by the sea, and if so describe them.
5) Based on your previous answers do you think that the sand is mainly made up of local geology or material transported in from further afield?