The Dublin Stone Show

Building Stone in Ireland

In the 2 months since I had volunteered to produce the GSI stand at the inaugural Dublin Stone Show, I had seen a lot of the geology of Ireland and its associated ancient monuments and historic buildings and I now felt well prepared for this unique event.

Niahm Redmond and Matthew Parkes at the GSI trade exhibition stand

Working with Niahm Redmond, our role was principally to promote the GSI’s expertise in petrographic analysis and sourcing of building stones for the repair of the nation’s historic stone monuments, as well as various support services to the quarrying industry.

Held over 2 days at the Citywest Hotel, on the outskirts of Dublin, the venue was perhaps more suited to general conferences than an international stone show and the decor was a distraction from the exhibits themselves; however, it proved to be a well attended event – by both exhibitors and a wide variety of visitors from all over the world.

Although much smaller in scale than similar events that I had attended in London, a full range of materials and products were on display. From Ireland, there were several suppliers of Irish Blue Limestone, Liscannor Stone and Donegal Quartzite, whose riven texture makes it especially good for paving and internal flooring, where a non-slip surface is required.

From the UK, a few major stone suppliers exhibited a wide range of sandstones and, as usual at these events, a wide variety of polished granites and marbles and other stones from all over the world were on display, with German and Italian stone producers featuring prominently.

Jura limestone from Germany

 

Manning the stand for most of the days, and answering questions from a wide variety of professionals and members of the general public, I didn’t have much opportunity to talk to the various exhibitors, except to introduce my friend Giovanni to the suppliers of Irish Blue Limestone. 

Having stayed in Dublin for 2 months in the summer, to learn English, he had come back especially to this event to source potential suppliers of this stone for his own stonemasonry business back in Florence.

Un tavolo in pietra lavica ceramizzata

At the end of the event, I was pleasantly surprised to discover that he had been talking to a supplier of Mt. Etna basalt from Sicily who, at the end of the event, had decided to leave their products behind and that I could have anything that I wanted. 

Taking advantage of this "once in a blue moon" opportunity, a phone call was all that was needed, before a helping hand arrived. The ceramicised basalt table now takes pride of place in my living room and the slabs add continental flavour to the garden of my supervisor.

A couple of days after, the director came up to me and congratulated me on the success of the Dublin Stone Show. Whilst very happy to know that our efforts were appreciated, I felt a little embarrassed, because shortly after arriving at the GSI, he had come up to me and introduced himself. Having seen so many new faces and so many new offices, I just blurted out “haven’t we already met?”. It was not my best introduction to a new boss! 

A report on the Dublin Stone Show

A Field Trip at White Rock

White Rock at Killiney

I had been surprised at the mild weather throughout autumn in Ireland, compared to the UK, and I wanted to make the most of my last month and see some more places around Dublin. Now well into November, I made use of the DART again to visit White Rock, at Killiney Beach.

Mica schist and aplite veins

Situated right next to the Killiney station, this coastline has traditionally been very popular with bathers but, for the geologist, it also contains a wide variety of interesting rocks and features that makes it a well used field trip location – for undergraduates at Trinity College and University College, which both have a good reputation.

Although I only discovered this later, an excursion organised as part of the Education and Outreach services at the Geological Survey of Ireland, explores 500 million years of Earth’s history – from the Cambrian to the Quaternary periods – that can be found along this short stretch of coastline. Aimed at the general public, guided walks along this beach provide a good introduction to the rocks of Ireland.

My job, to survey this County Geological Site, required me only to look at the contact between the Leinster Granite, which forms the Wicklow Mountains, and the Ordovician rocks into which it was intruded in Devonian times.

Geology students from University College Dublin

Never knowing quite what to expect when seeing some new geology, the jagged outline of what I presume to be White Rock gleamed in the afternoon sunshine and forms a spectacular local landmark. Much to my surprise, I wasn’t the only person there and I had arrived at the same time as students from University College Dublin, who were looking closely at the rocky cliffs.

Mica schists and granite at Killiney Beach

It is an excellent example of contact metamorphism, with mica schists displaying several growths of the mineral andalusite along the plane of cleavage and larger joints - and other structural features that show the metamorphic fabric of the Ordovician rocks.

Mica schist with andalusite

Diverging upwards, away from the main body of the granite - comprising quartz, white feldspar and white mica - thick veins of aplite and pegmatite pervade the schist. Here, the different rates of the cooling of the magma, and how this affects the size of the crystals and textures, can easily be demonstrated. Although never being as well developed as in such places as Glendalough, lead and copper were once mined here and a disused and inaccessible old adit can be seen in the cliff.

A view from White Rock towards Killiney Beach

Granite in Co. Dublin

An aerial view of Dalkey Quarry

With the Dublin Stone Show only a few weeks away, I had plenty to keep me busy in the basement at the GSI, writing up my site reports from my tour of southern Ireland and incorporating a selection of my photographs into one of the display panels.

Dalkey castle

Knowing now that I had to prepare to come back to Rotherham, I now started to put in some overtime work and, at the weekends, I made good use of the DART railway to explore some of the County Geological Sites that can be found around Dublin.

At Dalkey Quarry, where the grey Devonian granite was used to build the harbour at Dún Laoghaire and - and for the embankments along the River Thames in London - there is a vast excavation in the Wicklow granite. Nowadays, it is quite overgrown, thickly wooded in place and it now forms part of Killiney Hill Park. It is a popular site for rock climbers and there are several well marked and well used paths, solid stairs and excellent viewing points, where Dublin and its southern suburbs can be appreciated.

Returning to Dalkey, I had a quick look at its castle before getting back on the DART and then stopping off again at Blackrock, where its granite breccia provides yet another example of some very interesting geology in Ireland. Here, embankments and sea defences have encroached upon the underlying geology and small outcrops that have not been covered are all that remain.

A general view of Dalkey Quarry

Whilst walking around, I didn’t stop to look closely at the petrological details of these rocks, but it is a good location for undertaking research and, as one of several easily accessible sites in this area, it is a good stop off point on a geology field trip.

A coastal exposure of granite breccia at Blackrock

Granite in Co. Wicklow

The old quarry at Ballyknockan

On the last day of my short tour of southern Ireland, to survey some building stone quarries that were listed as County Geological Sites, my plan was to visit Ballyknockan and Ballybrew which, historically, were very important producers of granite.

A boundary wall at Ballyknockan Quarry

Staying overnight at Blessington, having driven from Kilkenny the previous day, I was situated on the edge of the Wicklow National Park, where the hard granite was  sculpted into spectacular landscapes by glaciers in the Quaternary Period.

Ballyknockan overlooks the Blessington Lakes, where the River Liffey has been dammed to provide a hydroelectric power station and a reservoir, and there are some good views of the foothills of the Wicklow Mountains.

Like in the UK, the production of granite in Ireland has declined considerably in recent years and, although there were some operational workshops at the Ballyknockan quarry, much of this sprawling site had long since been disused. 

Away from the current working faces, small exposures of the granite can be observed in a relatively safe environment and here, the old traditional buildings and plant and machinery also provide interest for the industrial archaeologist.

General views of Ballyknockan Quarry

Having had a good walk around the site, checking the boundaries and making a note of the points of interest, I headed off into the heart of the Wicklow Mountains. I wanted to stop and look around Glendalough and enjoy a drive through this landscape, but I was thwarted by the heaviest downpour of rain that I had encountered during my stay in Ireland.

General views of Ballybrew Quarry

At Ballybrew Quarry, which has now closed, the old quarry faces were not easily or safely accessible, with one part being filled with water, and fenced off, and the other being littered with large piles of off cuts and waste material, which would make visits by the general public quite hazardous. With my work for the week finished, I finally arrived back in Dublin...