To claim this EarthCache you will need to visit the location given and gather some information.
Once you have the information please message or email the answers to me.
Please bear in mind that the location is remote and a significant undertaking to get there.
Also there is no mobile signal.
Please feel free to log your find and send your answers at the same time.
Finally if you wish to add a photo please feel free to do so.
The focus of this cache is the sand on the ‘beach’ of Birk’s tarn.
You will need to look at this sand and answer some questions about how it came to be here.
This a rare example of weathering occurring in the absence of erosion.
So first I need to explain the difference between wreathing and erosion
Weathering and erosion are processes by which rocks are broken down and moved from their original location. I all depends whether a rock's location is changed: weathering degrades a rock without moving it, while erosion carries rocks and soil away from their original locations. Weathering often leads to erosion by causing rocks to break down into smaller pieces, which erosive forces can then move away. These two processes often occur together when water, wind, ice or glacial action takes the particles that have broken off during wreathing is eroded to another location, down-stream/wind.
The rock type here is mill-stone grit, here is some information about the formation of mill stone grit.
Millstone Grit, is made from sand, grit and rounded pebbles of quartz and some feldspar. It is known as ‘Millstone’ Grit because it was used to make millstones for watermills, however it has also been used for building stone, paving slabs and various other applications Its coarseness gives it a very rough surface which is great for climbers
The Millstone Grit was deposited as part of a vast river delta system, formed where a river met an ancient sea. The sand grains and grit material was washed down from a range of ancient mountains formed between 430 to 380 million years ago, during the Devonian period, when the modern day North America collided with Europe. The sediments were later eroded and deposited some 60 million years after during the Namurian stage (326-313 million years ago) of the Carboniferous period.
The sediments were deposited as multiple, overlapping and evolving sandbanks within the river delta. As the water flow varied different layers were formed and if you look carefully you will see some fine lines, these are called bedding planes and can cause weaknesses in the overall rock structure.
Because the stone is hard it is a rough, hard stone but wind and water are breaking it down with small particles being broken off all the time. This location is quite flat with no obvious way for the broken off particles to be washed away. Consequently, as the grains break off they stay where they fell. This is a slow process but constant so the particles build up and form what looks like a white sandy beach.
So at this location I wish you to look at the particles and beach and answer the questions below.
- Please describe the location, concentrating on the texture large stones and the properties of the sand on the ‘beach’
- Please explain how this white sandy beach can be on the shores of this tarn, giving reasons for your summations.
- Please tell me the state of the water level in the tarn when you visited, was it full or not?
Thanks for visiting this location, I know how hard it is to get here and how much effort is required.
Remember there is no mobile signal up here so take care and I would advise not to venture up here solo.
Happy Caching