Read the description carefully, study the surroundings of the given coordinates, send answers to questions via e-mail or the message center, then log the cache.
Geology of Ireland
For a relatively small area, 70,000 km2 Ireland has a diverse geology. One of the most interesting aspects of the geology of Ireland is studying its origins.
Studies of plate tectonics tell us that Ireland once had a very different setting. Hundreds of millions of years ago the land that makes up Ireland as we know it today existed on two continents known as Laurentia and Gondwana that were separated by an ocean called Iapetus. The northern part of Ireland was located on the continent of Laurentia, preserved as parts of modern North American. The southern part of Ireland was located on Gondwana, now preserved as large parts of Europe, Africa and Australia.
Over 470 million years ago the ocean was closing and eventually the two continents collided, the impact of this collision can be seen in the way mountains over much of the island display long axes that trend north-east to south-west - a direction that reflects the line along which the plates clashed. A scar from Dingle on the west coast to Clogherhead on the east shows the line along which the two continents combined.
The bedrock of Ireland
The bedrock map of Ireland shows a wide variety of rock types which have originated at different periods of geological time.
The oldest rocks are metamorphic and are found in areas such as Malin Head in Co. Donegal. They originally formed as igneous rocks 1750-1780 million years ago.
Other old metamorphic rocks include the slates that have given rise to the slate quarry at Valentia Island, Co. Kerry, and the quartzites that are found in Counties Donegal and Wicklow.
Extrusive Igneous rocks, igneous rocks that have formed above the earth’s surface, are common in the north-east where the basaltic lavas have given rise to the Antrim-Derry plateau. Intrusive igneous rocks, igneous rocks that formed below the earth’s surface, such as granites can be seen in Counties Donegal, Armagh, Down, Wicklow and Galway.
Sedimentary rocks are widespread. They include the Old Red Sandstones from the Devonian period. These are common in the 'ridge and valley' landscape that runs across much of south-west Ireland. Limestone also covers much of the country most notably in the midlands and in areas such as the Burren in Co. Clare.
Irish Fossil Limestone Formation
370 Million years ago, at the floor of a shallow sea, a rich, coral-like fauna and prehistoric shellfish thrived in the warm waters. Carried by the waves into inshore areas, the spent shells and corals combined with the sediment to form a unique and compact natural stone.
Irish Fossil Limestone is not only one of the most compact sedimentary rocks, the fossil fragments create a distinctive appearance. Finely dispersed carbon throughout the stone mass results in a typical, blue-grey colour.
Fossils appearing in limestone and example areas of discovery
A Coral fossils are identified by a series of 'dots' in a group.
B Bivalves can vary in shape and size but commonly look like circles or 'C' shapes. They are cross sectional views through the valves of shelled organisms (like mussels and clams).
C Brachipods are similar to bivalves but usually have one valve bigger than the other.
1 Ballinasloe
2 Kilkenny
3 Threecastles
Questions - send answers to questions via e-mail or the message center, then log the cache.
1) Explain what caused the long axes of the mountains from northeast to southwest?
2) What is the chemical formula of limestone? (for example H2O)
3) Describe the fossils at the listed coordinates-what colour are they? Are they 2D or 3D (trace or transitional fossil)? What is the average size of the fossils?
4) What fossils can we see here and for what areas of discovery? (check out the sample images above, for example A3)
5) I will be happy if you attach a photo according to the pattern to your log.