Question: do you have an interest in rocks such as basalt and granite?

Kevin Motherway answered on 8 Nov 2014:

Yes igneous rocks are my favourite. It a little bit hard to get excited about sedimentary rocks (mud anyone. Any find mud thrilling? ). There are some really fantastic volcanic rocks on the Dingle peninsula and when you learn to read the sequence of rocks it’s a really dramatic story of massive falls of ash and huge volcanic bombs being thrown kilometres and lava flows all raining down on top of sediments full of trilobites. There are really cool granites in Wicklow, Donegal and Galway that came up from melted lower crust and intruded into the local rock and crystallised maybe over millions of years and finally came to the surface due to uplift of the rocks during folding and the rocks above being eroded away.

All these volcanic rocks erupting and granites intruding into the land happened during the closure of an ocean, called the Iapetus Ocean that stretched between two continents called Avalonia in the South and Laurentia in the North. The two continental plates came together causing all the fireworks and also scooped up all the ocean sediments and minerals that were on the ocean floor. So there’s a line from Navan to Limerick that marks the line called the Iapetus Suture where the two continents met and some of the largest Lead-Zinc deposits on the planet were scooped up from the Iapetus Ocean and deposited there so that’s why we have Tara mines in Navan, Galmoy, Lisheen Silvermines mine in Tipperary and Kilkenny and deposits in Pallas Green in Limerick that may be developed into a mine soon. So Ireland was in two halves on two completely different continents North and South until about 400 million years ago.

Happy to follow up with any more questions! Keep ’em coming.