Off-Road Lanes for Cycling in Kildare and Wicklow

Lane from Barretstown to Bishopshill Commons. © Eugene Brennan

I'm always on the lookout for new trails and farm lanes for cycling on. Some are marked with a cul-de-sac sign, and just end up at farmhouses. However, others actually link two roads. Usually, there’s no sign at the junction where they meet a main road, or even a road number, so it can be a mystery where they go.

Devils Tower, the Hill of Allen, the Valley Park and Close Encounters of the Third Kind

Devil's Tower in Wyoming. Ben Stephenson from Cleveland, OH, CC BY 2.0 , via Wikimedia Commons

If you were watching Close Encounters of the Third Kind this afternoon (I hadn't seen it for maybe 15 years), you would have seen the towering rock formation that's used as a plot device and features in the end of the movie when the huge spaceship appears and the aliens emerge. This is Devils Tower in Wyoming,  a laccolithic butte formation, composed of igneous rock.

Solar Panels, Local Mines and an Adit in Hollywood Glen

© Eugene Brennan

I cycled up to the Glen of Imaal yesterday afternoon. My route took me via Kennycourt to Grangebeg, Lemonstown, Hollywood and then up the steep road from Donard to the glen. I usually go this way because the road is quieter, with very little traffic and then return via the busier but more downhill Knockanarrigan road.

The L8333 road from Hollywood to Donard runs parallel to the N81 and through the picturesque Hollywood Glen. It's is one of my favourite places in west Wicklow, lined on both sides by tall pine trees and rocky crags in places.  A planning application has been lodged recently to Wicklow County Council on behalf of Wicklow Renewables Ltd for a solar PV development  and battery energy storage system (BESS) facility in the area. According to the planning application, the site will cover an area of ca. 65.4 ha and consist of an array of solar panels, 192 BESS units comprising 22 modules, a 38 kV substation and other ancillary works. The location of the proposed solar development is on raised ground behind the treeline in the photo below. The boundary of the proposed development extends southwards and to the west towards the N81.

Hollywood Glen. © Eugene Brennan

Notice about planning application by Wicklow Renewables Ltd. © Eugene Brennan

Mines Local to Kilcullen

Apart from the Modubeagh and Gracefield coal mines near Wolfhill, one of the nearest mines to Kilcullen was the Deerpark Colliery near Castlecomer, which opened in 1924. Anthracite, a high carbon coal, also known as "Kilkenny Coal" and used before coke for ore smelting, was extracted from the  mine. This was  transported on a dedicated branch line that ran through Castlecomer and joined the Waterford & Maryborough branch of the GS&WR, itself a branch of the Dublin to Waterford rail line. The Deerpark colliery closed in 1969.  The region south of Ballylinan, (located 6 km south of Athy) including parts of counties Laois, Carlow and Kilkenny, is riddled with the remnants of now closed coal mines.  These mines tapped into several anthracitic formations that are part of the Leinster Coalfield. Mining has also taken place in Wicklow since ancient times and one of the most well known mining areas is around Avoca, where sulphur, lead and copper were extracted. Lead was mined at Glendalough and also in its sister valley, Glendasan.
A useful resource is the OPALS (Online Prospecting Application Licensing System) interactive webmap, from the Department of the Environment, Climate and Communications, which  provides locations and information on historical and current mineral exploration and mining in Ireland.

OPALS (Online Prospecting Application Licensing System) interactive webmap. Image courtesy and © Tailte Éireann

Hollywood Mine

Halfway between Hollywood and Donard and now overgrown with briars and lady ferns is what appears to be the entrance to an adit. The adit is partially flooded and the echo of water dripping from the roof can be heard. While a mine shaft is a vertical structure, an adit is a horizontal passage that extends sideways into a mine. This is marked on the c. 25" OSI map and is denoted as "Spa Hole" and "Iron Mine Disused". I haven't been able to find any information so far on this working, other than a geological report on the glen that indicates it's a glacial feature, deeply carved by high-energy, water run-off as ice melted. The second map below from Geological Survey Ireland shows audited sites, with links to reports accessible by clicking the link in the pop-up.

Entrance to Spa Hole adit. © Eugene Brennan

"Spa Hole" marked on 25" OSI map. Image © Tailte Éireann

Audited Geological Heritage. Image © Tailte Éireann Geological Survey Ireland

The Great Irish Fossil Hunt and Church of the Sacred Heart and St. Brigid, Kilcullen

Made with Bing Image Creator.

At least one of the marble columns in the parish church in Kilcullen has a series of somewhat regularly-spaced white patches. I've often wondered whether they were the vertebrae of the back bone of some prehistoric marine animal. Marble is a metamorphic rock, formed when limestone is "cooked" and melted by heat from magma within the Earth. Limestone itself is a sedimentary rock, formed when marine organisms die and their skeletons or shells settle to the bottom of the ocean. Over tens or hundreds of millions of years of geological time, the deposits build and the layers are compressed into rock by the immense pressures.

The most interesting fossil I've found was from about 6 feet deep when I was helping to dig a hole near Kilmeague. The lump of red rock was embedded with cockle shells, presumably dating back hundreds of millions of years to an era when Ireland, or rather the land fragments that would become the island, were located south of the equator.

University College Cork are running a project at the moment called the Great Irish Fossil Hunt, lasting from the 2nd April to 31st August. They're asking the public to be on the lookout for what might be fossils, some of them even hidden in the fabric of buildings. Photos can then be sent to the UCC team. More info here.

Plate Tectonics and Finger Nails

Image created using by Bing Image Creator.

Plate tectonics is a theory, superseding and encompassing the earlier continental drift theory, that the Earth's continents make large scale movements over geological time. The process is really slow, and occurs at the same rate finger nails grow: about 0.1 mm a day. That's 36.5 mm a year, 36.5 m per millennium and 36.5 km per million years or 3650 km in 100 million years. Ireland, or more correctly the parts that make up Ireland, were once located south of the equator in tropical seas. (I found a rock once in the midlands, when helping to dig a deep hole. The rock was embedded with large fossilised cockles). Over millions of years the parts drifted northward and merged, to make the island. The dividing line between the northern and southern parts of the island of Ireland runs roughly down a line between Louth and Kerry.

Skerries Rocks

Rock showing the influence of volcanic activity, on the coastline at Skerries. © Eugene Brennan

Some interesting rocks from the Loughshinny, Skerries, Balbriggan area I came across on a walk along the coastline. Also a smuggler's cave I want to explore the next time I'm up there. I presume the holes in the rock are from volcanic gases that made the rock froth when it was molten. The white vein is a sedimentary layer that ended up on its side when the strata became folded over horizontally (I think that's what the GSI said when I asked them). Skerries is an area of interest geologically because of the complex number of geological formations from different periods. Further north at Clogherhead is one end of the boundary between the northern and southern landmasses that came together 470 million years ago to "make" the island of Ireland. That boundary line between the two sections extends south westwards towards the Dingle Peninsula.

Vein in rock strata. © Eugene brennan

Smuggler's cave near Loughshinny. © Eugene Brennan

Santorini Tremors

Scenes from Santorini © Eugene Brennan

A beautiful island with its scenic cliff-top walk from the town of Fira to Oia (pronounced E-ah) in the north. And the 600 or so steps from the old port to the top of the cliffs are good leg exercise! The Minoan eruption, one of the largest eruptions in recorded history, occurred 3600 years ago, leaving a collapsed caldera surrounded by water at the centre of the island. In 1956, an earthquake with a magnitude of at least 7.4 caused huge damage on the island, killing 53 people. Santorini is one of the islands of the Cyclades group, on the boundary of the African and Aegean tectonic plates, where tremors are common. Santorini and neighbouring Milos both have dormant volcanoes.

More information in this BBC News report:

 

"Santorini rocked by more earthquakes as uncertainty grows"

BBC World Service — The Deepest Man-Made Hole in the World

Kola Superdeep Borehole. Image courtesy Andre Belozeroff, CC BY-SA 3.0 via Wikimedia Commons.

I was listening to this in the early hours of the morning. Witness History is a short factual insert in the BBC World Service schedule in which the interviewer speaks to someone who was present at events of historical importance. In this program, the presenter Rachel Naylor was talking with Prof David Smythe, a geophysicist who worked at the Kola Superdeep Borehole site in Russia for four months. The borehole was drilled to a depth of 12 km.

Sink Hole, Impact Crater or Turlough?

Image courtesy Google Maps and Maxar Technologies

I've often wondered about this circular pond area at the back of what's called "Brownstown House" on the first edition c. 1837 OSI map or 19 Mile House Inn on earlier maps, once the meeting place of 1798 rebels and a home of the McDonnell family in past decades. The Geological Survey of Ireland interactive map however doesn't show any magnetic anomalies which I think would be the case if it was a mini crater site, meteorites often being made of iron. But not all of them are. Maybe the circular shape is man-made or a natural phenomenon due to the edges falling in uniformly all around the perimeter because of erosion and sheep wandering around it over time.

Does anyone know anything about it?
Maybe it's a turlough?

 

There is a red "hotspot" of magnetic intensity further east, but I think that may be due to the covered KTK landfill (Planning permission has now been lodged for a solar farm there). When I zoom into the map, the shading disappears, so I can't identify whether it aligns with the landfill. I've queried this bug with the GSI.

 

Edit: This EPA report from 2011 mentions "..reclamation of metals and metal compounds" at the KTK landfill.

 

https://epawebapp.epa.ie/.../lic_eDMS/090151b2804386da.pdf

 

A close-up of the pond. Image courtesy Google Maps and Maxar Technologies

  

6" c. 1837 map, courtesy OSI (Tailte Éireann)

The red area shows a region of higher magnetic intensity. Map courtesy GSI (Tailte Éireann)

The Geological Survey of Ireland's Tellus Survey

You may remember a low-flying aircraft, making multiple passes over Kilcullen a few years ago. This aircraft was collecting various forms of geophysical data about the ground surface as part of the Geological Survey of Ireland's Tellus survey. The aerial part of this survey involved scanning the ground, using onboard instrumentation and measured several properties including the magnetic field, radioactivity and electrical conductivity of the Earth’s near surface. A lot of this data, including results from ground-based geochemical surveying of soil, stream water and stream sediment is now available in interactive map form.