A New Years Resolution for 2022 was to write one dedicated earthcache per month for the year, showing some of the interesting places I've been and making it some form of a series. Some cachers love collecting a good series, others love earthcaches and others hate one or both. I love both. So try and find all twelve in this series, and earn some good bragging rights.
The Full list
This Earthcache
Not much caching for me in July 2022 - instead there were three trips to Castleblakeney in Co Galway - two for retro gaming weekends and one for a two day summer BBQ. Cork to there can be done through Charleville and Limerick, or Caherconlish and Limerick, or through Thurles and Birr. The latter had me passing this interesting piece of history, so my earthcache for this month went there.
A very fancy photo of the column, I should get paid for this
A short history
Birrs pillar, or "The Cumberland Column" as it used to be known, is the oldest monumental column in Ireland. It is a freestanding ashlar limestone Doric column erected in 1746, and is mounted on an ashlar pedestal with plinth and cornice. It formally supported a statue of the Duke of Cumberland which was removed in the early twentieth century. Prince William, the Duke of Cumberland, was once celebrated with statues, flowers and song, yet his reputation fell so far that, in 2005, historians voted him the ‘Worst Briton’ of the whole 18th century. He got his nickname from the battle of Culloden in 1746 when British forces met Jacobite rebels on Culloden Moor in Scotland. The British won, but their commander (Prince William) ordered "no quarter" be given to injured or fleeing Jacobites or to any civilians living nearby. Thousands were murdered in a spree of vengeance and what is worse is that William praised the most brutal of his officers - saying for instance that one "made a great slaughter". In 1915 Scottish soldiers got their revenge when they pulled the 'Butcher' from his pillar in the centre of Birr. Only his head and arm remain and are among the many historic artefacts kept at Birr Castle. There are no plans to put him back up again.
You'll find plenty more information about this column and the statue with a quick google - it's very interesting. This earthcache can be done just from this page and your observations.
Weathering
Weathering describes the breaking down or dissolving of rocks and minerals on the surface of the Earth. Water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering. Once a rock has been broken down, a process called erosion transports the bits of rock and mineral away. No rock on Earth is hard enough to resist the forces of weathering and erosion over time.
Mechanical weathering, also called physical weathering and disaggregation, causes rocks to crumble. Water, in either liquid or solid form, is often a key agent of mechanical weathering. For instance, liquid water can seep into cracks and crevices in rock. If temperatures drop low enough, the water will freeze. When water freezes, it expands. The ice then works as a wedge. It slowly widens the cracks and splits the rock. When ice melts, liquid water performs the act of erosion by carrying away the tiny rock fragments lost in the split. This specific process is called the freeze-thaw cycle.
Chemical weathering changes the molecular structure of rocks and soil. For instance, carbon dioxide from the air or soil sometimes combines with water in a process called carbonation. This produces a weak acid, called carbonic acid, that can dissolve rock. Carbonic acid is especially effective at dissolving limestone. When carbonic acid seeps through limestone underground, it can open up huge cracks or hollow out vast networks of caves. See The Burren for a good example of this.
If a limestone is full of fossils, the rock can erode, causing the fossil remains to stick out. This occurs if the rock is formed of a highly crystalline calcium carbonate known as 'sparrite'. This dissolves more slowly than the micro-crystalline 'micrite' that makes up the rest of the stone and as the surface is lowered the fossils are left standing above it.
Questions
Answer the following questions and send them to me via the Messenger or via an email. Feel free to log the cache before you send them, but please send them within a reasonable timeframe. Sending no answers may result in your log being deleted, with fair warning. Optional questions are just that, optional, they are for the earthcache nuts (like me) who enjoy looking that bit more closely.
At the given co-ordinates you will see the column. Look at it as closely as you can, and notice the plaque on the southern side.
- Briefly describe, in your own words, some of the various forms of weathering.
- What rock do you think is the column made out of?
- Do you think this column will weather quickly, or slowly?
- Given your answer to (3), do you see any evidence?
- What are the three dates on the plaque?
- Optional: Describe the stones in more detail - what do you see and where do they come from?
- Optional: Do you see any sparrite here? Why/Why not?
References:
- https://www.independent.ie/irish-news/no-place-on-birrs-pillar-for-butcher-pillar-of-society-the-column-in-birr-is-due-to-undergo-restoration-26584397.html
- https://www.buildingsofireland.ie/buildings-search/building/14819004/cumberland-column-emmet-square-townparks-bb-by-birr-offaly
- https://www.independent.ie/entertainment/books/book-reviews/the-fall-of-an-aristocratic-english-butcher-in-an-irish-midlandstown-40746443.html
- https://education.nationalgeographic.org/resource/weathering