A monument in memory of P A McHugh ( 1858 -1909), owner of the Sligo Champion, Mayor of Sligo and MP for North Sligo, was erected in a prominent position outside the Post Office in Sligo town in 1916.The statue was moved to its present position in front of Sligo Town Hall in the 1970's to make way for revised traffic system in the town centre.
Rocks can be divided into three main groups, sedimentary, igneous and metamorphic. All three groups are seen here !
Sedimentary rocks are laid down as particles of material such as sand or mud and then hardened by compaction and lithification into sandstones, siltstones, mudstones and limestones. Fossils are often preserved in these rocks.
Igneous rocks crystallise from magma originating deep beneath the Earth’s surface and may be extrusive (i.e. lava flows at the Earth’s surface) or intrusive (emplaced within the Earth’s crust, below the surface).
Metamorphic rocks are sedimentary or igneous rocks that have been altered by changes in temperature and/or pressure. New minerals grow in response to these changes and their composition depends on the composition of the originalrock, and the temperatures and pressures that affect it.
The freestanding white life-size figure of McHugh, is of Cararra marble, is the work of sculptor, Joseph Hanrahan, and sits on top of polygonal grey Ballisodare limestone capital with celtic motif carvings on pulvinated base which sits on three clustered pink Newry granite columns which again is on top of limestone base and plinth with three protruding limestone semi-round seats !
Carrara marble is a high quality marble quarried in Tuscany,Italy and has been in use since the time of ancient Rome. When formed with very few impurities it is white in colour and being composed of calcite it has a hardness of 3 on the Mohs scale.
Limestone is calcareous sedimentary rocks formed at the bottom of lakes and seas with the accumulation of shells, bones and other calcium rich goods. It is composed of calcite (CaCO3). The organic matter upon which it settles in lakes or seas, are preserved as fossils. Over thousands and millions of years, layer after layer is built up adding weight. The heat and pressure causes chemical reaction at the bottom and the sediments turn into solid stone, the limestone. It can also be a chemical sedimentary rock formed by the precipitation of calcium carbonate from lake or ocean water.
Granite is formed when magma with silica contant cools beneath the earths surface, solidifying and forming interlocking crystals. The slower the cooling the larger the crystals.The Newry granite is rich in biotite which are the black grains and give the rock the speckled effect.
To claim this earth cache,you must carry out these educational tasks as required by the Earthcaching organisation as a condition of logging the cache. Contact me via my profile ( please do not post in your online log) the answers to the following tasks :
1) Looking at the granite, describe the colour and feel of it. You can see the individual black specks, how big are they ? ( Length/width ) Are they all roughly the same size and shape ?
2) From what you have learnt about granite in the text above, would you say going by the size of the specks that this granite has cooled slowly ? Give your reasons
3) Looking at the limestone rock at the bottom,can you see any fosssils in it ? If yes describe them, colour,size and shape and what do you think they are ?
4) There are three rocks types used in this statue, which type of rock is from what group ? i.e limestone / sedimentary
5) Can you give uses ( apart from statues) for each of the rock types ? i.e ground down limestone is used in cement
6) While not obligitory it is always nice to see a photo of your visit.
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