City sights
Best of luck!
Limestone cliff faces
Japanese Gardens in Ballinlough
The below image to left shows diamicts – crevasses in the limestone eroded by water and ice. Then after or during erosion, sediments filled inside the crevasse. These can be found along the right side of the limestone cliff – amongst all the graffiti.
The last image gives a closer look on the limestone. While much of it is eroded and covered, there are glimpses of the life that existed back in the Carboniferous tropical reefs 350 million years ago. The segmented fossils seen is the stem from a crinoid.
Glacial river valley
The Glen River Park
Sometimes vegetation can be a geologist’s bane when looking for fresh rock outcrops. The Glen River Valley has several Old Red Sandstone-exposures, but these are largely inaccessible due to thick gorse and fern growth. That’s okay too as the landscape is what makes the The Glen interesting.
The Glen River Valley is worth a visit due to its shape in relation to the geology underneath. The Old Red Sandstone-layers making up the valley are deformed into a huge U-shaped fold due to the Variscan Orogeny – this kind of fold is also known as a syncline. This syncline also has several faults which made it an ideal path to cut through for the River Glen that follows the valley. The valley is also of economic significance for Cork as gravel pits and rock quarries once dotted the area inside and around.
Old Red Sandstone fold
Upper John Street
Originally, the rocks of Cork were laid as flat, horizontal layers. However, millions of years later, these layers were subjected to a lot of pressure and temperature when landmasses collided. We call this period of continental collisions the Variscan Orogeny.
This deformation is visible in Cork’s rocks throughout both the county and the city. Along Leitrim St and Upper John St you’ll find the most accessible outcrops showing shortening, faulting and folding features of the rocks. In the city, this is most evident in the Old Red Sandstone-layers such as seen at Upper John St.
Bricks with plant fossils
Rutland Street
Great exposures of Devonian plant fossils can be found and studied along the coasts of Munster. Luckily, you don’t need to leave the city to see these in detail. On some of the buildings along Rutland Street you’ll find fossils with branches on green-greyish Old Red Sandstone. These rocks were likely sourced locally as plant fossils have been found in the bedrock of the city.
Knowing that these are some of the earliest large plants on Earth makes this an amazing sight. In the picture below, you can slide the middle bar back and forth if you need help distinguishing the fossils.
Limestone cliffs along disused railway
Blackrock-Passage Greenway
Recently done up, the Blackrock-Passage Greenway, or more commonly referred to as the Greenway, has more space and greater accessibility. There’s handy access to limestone outcrops from the Blackrock station platform and all the way down to the pedestrian bridge crossing the South Ring Road.
Dressed on many of these are large ferns that thrive under dense tree canopies keeping the air damp and cool. There are also small rockslides and mudslides along the trail creating alluvial fans and loosening limestones for you to study closeup.
Disused limestone quarry
Beaumont Park and Quarry
Numerous quarries dotted Cork city over the past centuries, but today most of the industries have relocated away from urban areas. Inactive quarries are great places to geology, so having Beaumont Quarry a short walk from the city centre is valuable. The quarry and park nearby allow for a bit of nature in the middle of the concrete jungle.
There are also cave systems underneath the quarry which obviously shouldn’t be explored without permission or seasoned speleologists. These cave systems are a key feature of limestone exposures due to the rock’s reactivity with acids and water.
River Lee and Gunpowder Mills
Ballincollig
At the most western edges of the city boundaries lies Ballincollig. With a busy town centre, the locals luckily have access to the Regional Park that follows the curving path of the River Lee. There are many geological features to behold along the park including exposures of Quaternary glacial sediments and the Lee itself.
The bedrock of Ballincollig is mostly made up of Carboniferous limestone. This is best reflected in the walls of the historical amenity the Ballincollig Gunpowder Mills which can be found in the Regional Park. There’s plenty to tell about these industries, but we’ll let you go in-person and explore for yourself.
Trace fossils from Clare
Blackrock-Passage Greenway
If you’re having trouble finding these, check out the image below. They make up many parts of the park.
