The Formation of Rocks in Ireland Essay Example for Free

The Formation of Rocks in Ireland EssayIt is the most widespread type of intrusive flaming jounce at the countrys surface. Igneous lists form when molten rock is erupted at a volcano and then cools and hardens to form red-blooded rock (Holden, 2012). Granite rock is created when magma is forced between other rocks thick-skulled within the earths crust. The magma then cools due to the debark in temperature and crystallizes in caverns deep within the earth. The molten rock cools quite slowly over time, which allows the crystals to bugger off and develop inside the molten rock. Granite is transported to the surface of the earth by plate tectonics.The collision of continental plates moves the granite from deep within the crust of the earth to the surface. Granite is found in Ireland in the Wicklow Mountains. (http//www. talktalk. co. uk/reference/encyclopaedia/hutchinson/m0015252. html) Granite is distinguished by leash features. Firstly, granite is composed of large miner al grains that bind tightly together. Secondly, granite always contains the minerals of quartz and feldspar. (http//www. windows2universe. org/earth/geology/ig_granite. html) These minerals represent granite a light complexion, generally a pink or white colour.Thirdly, almost all granite is igneous and plutonic. This is because it organize from a fluid state, which was magma and it formed in a huge, deeply buried body in any case known as a pluton (http//geology. about. com/od/ more(prenominal)_igrocks/a/granite. htm). Basalt Basalt is a common extrusive igneous rock. Basalt is commonly dark in colour. It has a fine-grained mineral texture which is due to the rapid engine cooling system of the molten rock after it is erupted at a volcano. The rapid cooling occurs due to being unresolved to the cooling air or water on the surface of the earth. Holden, 2012) Basalt is formed generally in three different surrounds Oceanic divergent plate boundaries, pelagic hotspots and at hotspot s and mantle plumes beneath continents. Basalt forms at marineic divergent plate boundaries at mid-ocean ridges. At mid-ocean ridges convection currents pull the plates apart creating a rift valley. This allows hot rock from deep within the earths mantle to melt and erupt onto the seafloor forming basalt. (Honan, 2011) At oceanic hotspots basalt is also formed. Hotspots are areas in the cente of tectonic plates where hot plumes of magma force there way to the surface.Basalt is formed at these hotspots when an eruption occurs on the ocean floor. If the eruptions are repeated enough times the basalt can build the volcanic cone larger and larger to form an island. The Hawaiian Islands are an example of this. (http//geology. com/rocks/basalt. shtml) Basalt is also formed in a continental environment where mantle plumes or hotspots can deliver large quantities of magma up to the earths surface. These eruptions generally form from fissures or vents and they educate some of the largest basalt flows on the continents. (http//geology. com/rocks/basalt. html) Basalt can be found in Ireland in the Giants causeway in County Antrim. Limestone Limestone is a repositoryary rock. Sedimentary rocks are created by the adjoines of chemical or physical weathering . The situate which is created from the processes of weathering can accumulate over time and eventually build up and harden to form inviolable rock. (Holden, 2012) Limestone in Ireland formed about 300 to 350 million years in warm shallow seas when Ireland move close to the equator. Over millions of years the bodies of dead marine creatures such as shellfish and coral cut to the seafloor and built up on the seabed.Mud and sand particles from rivers also fell to the seafloor and added to the sediment. Over time the slant of the accumalting sediment compressed the sediment. Water and air was pushed from the pore spaces and calcium carbonate from the sediment binded the rock together. The process by which loose gr ains of sediment are compressed to form solid rock is called lithification. (Honan, 2011) Chemical weathering and eroison of limestone rock produced unusual landscapes in Ireland called karst landscapes. An example of a karst landscape in Ireland is the Burren in County Clare. Honan and Mulholland , 2007) Sandstone Sandstone is an inorganically formed sedimentary rock. It forms when particles of igneous, metamorphic and other types of sedimentary rocks are transported by rivers and gather on the seafloor or in lakes. The sediment layers then become compacted and over time cemented together by silica to form sandstone rock. (Honan S. , 2011) Sandstone in Ireland was formed 400-350 million years ago when Ireland was situated 30 degrees south of the equator. During this period Ireland was experiencing some very ironic desert conditions.Many large rivers flowed across the dry landscape carrying the sediments which over time formed grey-haired Red Sandstone which can now be found in t he Cork and Kerry Mountains. (Honan and Mulholland , 2007) Schist Schist is a metamorphic rock. metamorphic rocks are produced from existing sedimentary or igneous rocks usually as a result of partial tone melting and recrystallization. The changes normally occur where there is high pressure such as under hundreds of metres of bedrock or where rock is crushed at the meeting point of tectonic plates. Many metamorphic rocks mystify a layered structure due to this intense external pressure.Metamorphic rocks are often harder and more resistant than sedimentary rocks. (Holden, 2012) Schist in Ireland was formed through regional metamorphism. This is when large areas of rock covering umteen thousands of square kilometres are metamorphsed. Schist in Ireland was formed about 400 million years ago during the Caledonian fold period. The rocks changed due to huge pressure on the rocks created by plate movement. This deformed the rocks and forced them deep into the earths crust where they were heated to temperatures up to 1,000 degrees.