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To fully understand and read a local landscape one must first examine the shape of that landscape and determine the elements that have moulded it. The rocks create the skeleton of our local landscape. To understand the origin of these rocks, we must travel back in time and imagine climates and conditions which are very different from those of our locality today.
While undertaking this exploration it is useful to keep in mind the following facts and timelines.
To begin our exploration of the landscape of south-east Galway we travel back approximately 500 million years, to a time when the land that we now occupy was located 30o south of the equator and the climate that prevailed was a hot, desert climate, similar to that found in Saharan Africa today.
Approximately 500 million years ago the land that was destined to become Ireland was located approximately where South Africa is found today. A great ocean, known as the Iapetus separated two great landmasses. The rocks that made up these landmasses were weathered and broken down over time. Their sediments were carried by rivers into the ocean and deposited on the seabed. Due to the movement of the earth’s plates, by about 400 million years ago, the Iapetus Ocean had eventually closed. The two landmasses on either side collided together. The rocks at the edges of the colliding continents and the rocks from the ocean floor were crumpled and crushed as the two huge continental masses met. The force of this ‘collision’ caused a chain of mountains to be pushed up across the area that would eventually become ‘Ireland’. These mountains extended into what would be Scandinavia and into Canada and the Appalachian Mountains of eastern North America. As soon as these mountains were created they began to be eroded. Torrential streams, typical of high mountains began to sweep down creating deeply cut valleys between sharp peaks and waterfalls. The fast flowing streams ripped away the loose rock, which had been deposited on the floor of the Iapetus Ocean, and dumped it at the base of the mountain slopes in great fans of debris, creating the material we refer to today as Old Red Sandstone.
At that time, nearly 400 million years ago, the climate was hot. Desert developed over huge areas. The mountainous land that would eventually become ‘Ireland’ was located close to the margin of a major continent. To the south was a sea. Over time the land subsided and the sea began to spread.
By approximately 340 million years ago the land that would eventually form Ireland had drifted to about 10o south of the equator and was covered by a warm, shallow tropical sea. This sea was teeming with life, full of corals and shellfish. As the marine animals and plants completed their life cycle their remains floated down to the seabed where the soft parts decayed and the hard skeletons built up in layers.
The mineral calcite, which is composed of calcium, carbonate and oxygen, precipitates naturally out of seawater. It is also extracted by marine animals to help them build their skeletons and shells. The naturally precipitated calcite and the animal and plant remains accumulating on the sea floor eventually compacted to form limestone. The skeletons of the marine organisms that lived in that sea long age are evident in this limestone as fossils.
Limestone rock underlies most of south-east Galway.
The rocks create the skeleton of our local landscape, but it is the forces of earth movements, climate and weathering that mould that skeleton and present us with the contours that surround us today. Although this landscape may appear permanent to us, it is forever changing and has been different in our ancestor’s time and will be different again in the lifetimes of our descendents. To fully understand this landscape we must accept that fluidity and constant change.
The two major rock types evident in southeast Galway today (Old Red Sandstone and Limestone) were laid down in flat, horizontal layers. Yet the landscape that surrounds us is full of dips, hollows and even mountains. Water flows on the surface in the east, while surface water is largely absent in the south – only appearing in times of heavy rainfall and in some years resulting in severe flooding.
Around 290 million years ago there was a period of major earth movements caused by continental plates colliding. This resulted in a mountain building episode in southern Europe which caused squashing stresses to travel northwards. These stresses pushed up the Cork-Kerry Mountains but by the time they reached southeast Galway they had only enough energy to fold and tilt the rocks – pushing up the Slieve Aughty mountain range. This small range of mountains creates a physical division between east and south Galway. Over much of the Gort lowlands the originally horizontal limestone beds were tilted to the south-south-east and fractured, causing microscopic cracks along north-south and east-west lines.
It took approximately 20 million years for the limestone to form. During that time the earth experienced many climatic changes. These changes included ice ages. Great glaciers moved slowly across the landscape scouring the surface and carrying away loose rock and soil. The last ice age in Ireland occurred between 25,000 and 10,000 years ago. At that time glaciers moved in a north-east to south-west direction across south-east Galway and out into Galway Bay.
About 10,000 years ago, the climate began to warm and the ice melted. However, the ice in the glaciers did not melt all at once and in a uniform way. Imagine a block of ice. As it warms, it begins to melt from the outside and the melt water trickles down the sides and flows away from the edges and underside of the block. Some parts melt quicker than others so that the block breaks down leaving smaller clumps of ice that melt more slowly. This is the way the glaciers melted.
As they melted the sand, gravels, stones and rocks that they had collected were dropped back onto the landscape. Today we refer to this material as glacial drift. Its deposition and the landscape features created when it was dropped, depended on how and where the ice melted.
Depending on the direction, flow and melting place of the ice sheets, glacial drift was deposited in different ways in different locations and so resulted in the creation of different landforms.
In east County Galway, kames are a common glacial drift landscape feature. They are small rounded hills of sand and gravel. They formed when the rate of melting of the glacier was greater that it’s rate of advance i.e. it literally stopped and melted where it stood, dropping its load onto the landscape. This produced the confused landscape of small hills that is found to the east of the Slieve Aughtys. This landscape feature is particularly noticeable around the Tynagh area.
Eskers were formed when the meltwater flowed under the ice like an underground river. The waters carried along sand, gravel and small rocks which settled out on the ‘bed’ of the river, in layers depending on the rate of flow. The heavier rocks and stones were dropped first and the lighter soils, sands and muds later. The ice formed the ‘banks’ of the river. When the ice ‘banks’ melted, the water of the river dispersed. The ‘bed’ survived as a long narrow sinuous ridge of layered sand and gravel, standing high above the surrounding landscape. The most intact eskers in south-east Galway are located in the east, with a very good example at Killimor.
When the meltwater ran off the sides of the glaciers, the glacial drift was deposited in lines parallel to the direction of the flow of the glaciers. This type of deposition created small hump-backed hills of glacial drift. Today, we refer to these hills as drumlins (droim-ridge or hill). They can be distinguished from kames, as they occur in lines. A line of drumlins extends in a north-east to south-west trend from the Slieve Aughty Mountains near Derrybrien to Tubber, indicating the flow of the glacier across south Galway into north Clare and out into the Atlantic.
The glaciers moved across south-east Galway from the north-east to the south-west moving out into Galway Bay. As they melted they left large amounts of glacial drift to the east of the Slieve Aughty Mountains, but very little to the west of the mountains. Because of this, the exposed limestone of south Galway was subject to subsequent weathering unlike the limestones of the east of the region which were protected beneath layers of glacial deposits.
Acid dissolves alkaline. Rainwater is naturally slightly acidic and can dissolve the alkaline calcite in limestone. It can create hollows in the surface of the rock. Where cracks and fractures occur it can flow through the cracks, widening them overtime as it dissolves the limestone. Where this type of dissolution occurs, a karst landscape is created.
The landscape of south Galway, especially in the area known as the Gort lowlands is an important example of an ancient karst landscape (paleokarst). It extends from the Slieve Aughtys in the east, to Galway Bay in the west, Craughwell to the north and is bordered to the south by the North Clare uplands and the county border south of Gort.
The very unique and special landscape, known as the Burren, consists of the North Clare uplands and the Gort lowlands. Both the uplands and the lowlands have the same main rock type, limestone, yet the contours of these two regions are strikingly different. Why is this? The geologists tell us that the limestone of south Galway has been exposed to dissolution for much longer than that of the North Clare uplands. Why and how did this happen?
To understand this, we must look at how the rock skeleton of our landscape has been weathered over time. As discussed under topic 1 the Slieve Aughty Mountains today are covered with Old Red Sandstone. However in the past this sandstone was covered by a layer of limestone, on top of which was a layer of shale. Rainwater flows at high speed downwards from high ground creating a powerful erosive action. On low lying ground, the flow of the water decreases in speed and so is less erosive.
The speed of erosion caused the shale layer to be eroded from the mountains first, followed by the limestone layer. As the waters tumbled off the mountains onto the lowlands, the shale layer covering the lowland was eroded away in an east to west direction. Today it is completely gone from the Gort lowlands and most of the North Clare uplands, but a small covering still exists at Slieve Elva and Poulacapple on the extreme western coast of the Burren. As the protective shale covering disappeared from the Gort lowlands first, the limestone in this area has been exposed to weathering over a much longer time period than that of the uplands. This has resulted in the gently folded limestone beds of the lowlands being eroded to form the flat plain we are familiar with today. This level of erosion has not yet occurred on the North Clare uplands further to the west. Because of this the karst landscape of the Gort Lowlands is much older than the karst landscape of the Burren uplands today.
When the glaciers moved over the limestones of south Galway they picked up and carried along any loose rocks, stone and soil; scraping and smoothing the surface of the underlying bedrock. When the ice melted a smooth, limestone pavement was uncovered. However that limestone pavement contained microscopic cracks. These had been created by the earth movements that tilted the limestones and pushed up the Slieve Aughty Mountains some 300 million years ago. Over the millennia, the rainwater that fell onto these rocks, worked its way into the cracks, dissolving the limestone and widening the fractures. The resulting networks of north-south and east-west fractures in the limestone pavement are known as grikes and the flat blocks of limestone which they separate are known as clints.
These landscape features are particularly evident to the west of the Ardrahan to Gort (N18) road.
In karst landscapes, rainfall disappears through fractures in the rocks, which eventually may be widened by dissolution to form large swallow holes (locally known as slugga) and underground cave systems. Most of the surface water flows through the swallow holes and caves eventually re-emerging through springs.
The Slieve Aughty Mountains form the main water catchment area for the Gort Lowlands. Three major rivers drain from the Old Red Sandstone uplands unto the karst limestone where they disappear underground at several large swallow holes along the edge of the limestone. The Owenshree River sinks just north of Peterswell, the Boleyneeddorish River disappears underground into the ‘Hammerhead Sinks’ to the south-west of Peterswell and the Owenadalulleegh River flows through Louth Cutra, emerging as the Gort River before sinking at the Punch Bowl. The Gort River re-appears a number of times between the Punch Bowl and Coole Lough, but does not appear overground any further west except in times of extremely bad flooding.
When the rivers disappear underground they enter sections of enormous cave passages, sometimes more that 10 metres in diameter. The water within the caves drains westwards to major intertidal and submarine risings at Corranroo and Kinvara.
Geologists and hydrologists believe that the cave fragments underneath the Gort lowlands today were once part of a vast cave system. Due to dissolution of the overlying limestone by weathering and glacial erosion, some sections of the caves have been destroyed, while others have been blocked by glacial deposits. The fact that the regional water table is very close to the surface and that drainage through the remaining cave system can be impeded contributes to seasonal temporary flooding of low areas on the surface landscape. This flooding forms the turloughs or seasonal lakes for which the area is famed.
Turloughs (tuar loch – dry lake) are seasonal lakes that form in a hollow or depression in a limestone landscape. Fluctuations in water level reflect variations in the level of the water table due to changes in rainfall. As the water table rises, in times of high rainfall, water enters the lake through underground springs. Water drains through subterranean channels and swallow holes as the water table lowers, during drier weather. Turloughs are common features in south Galway, the most notable being Rahasane, Coole Lough, Newtown Lough, Mannagh Lough and Cloghballymore Lough. Caherglissaun Lough is significantly different, in that it is a tidal turlough and the waters rise and fall with the tides of Kinvara Bay.
Springs are the points at where groundwater emerges at the surface of the limestone. As well as surface springs, several submarine and inter-tidal springs can be seen along the south Galway coastline at Corranroo, Doorus and Kinvara.
Wildlife and nature add much of the colour, texture, noise and mo vement to our landscapes. Woodlands, hedgerows, bogs, grassland, old stone walls, lakes and rivers are all places or ‘habitats’ where wildlife can be found.
Habitats are the places that livings things call ‘home’; where they live, feed, rear their young and/or take cover. Each plant or animal has a particular environment that it likes to live in and certain habitats provide these environmental conditions. For example, woodland plants such as bluebells and wild garlic love the shady, humid and relatively undisturbed environment found in woodlands. Birds like the robin, goldfinch and chaffinch make use of hedgerow habitats as hedges provide great cover and shelter, and are rich source of food for much of the year. Insects such as butterflies and dragonflies can be found in abundance in wet grassland and marsh habitats where the wildflowers provide a rich source of nectar and the long grass, shelter and a place to lay their eggs.
South-east Galway is largely a low-lying agricultural landscape. It is bounded by the Slieve Aughty uplands to the south, Lough Derg and the River Shannon to the east, and Galway Bay to the west. A wide range of habitats for wildlife can be found in this corner of Galway, many of which are of high nature conservation value and great beauty, and are wonderful places to explore.
The natural habitats that form the fabric of the south-east Galway countryside help make it beautiful! The rich patchwork of fields, stone walls and hedges, interrupted here and there with woods, turloughs, rivers, lakes, bogs and eskers all form part of the living landscape of south-east Galway. Highly valued recreation spots such as Coole Park, Rinville Park, Lough Rea and Lough Cutra are greatly enhanced by the rich array of natural habitats they contain.
Two types of bogs are found in south-east Galway: blanket bogs and raised bogs. Bogs are a type of peatland that usually have a rich mix of sedges, mosses and heathers growing on them. Peat builds up under waterlogged and acidic conditions to form bogs. Peat is just an accumulation of partially rotted plant remains! The waterlogging (which leads to a lack of oxygen) and acidity results in very low decomposition rates so that when plants die they are partially preserved in the peat.
Blanket bogs are found in upland areas such as the Slieve Aughties where the high rainfall and acidic bedrock (Old Red Sandstone) are perfect for peat formation. This type of peatland started to spread about 6000 years ago after the first farmers arrived and started to clear woodland to make way for agriculture. Woodland clearance opened up the soils to leaching of nutrients and iron from the soil, which led to waterlogging. Woodlands were often burnt to help clear the land and the charcoal layer produced clogged the soil also leading to waterlogging of the soils. The acidic bedrock produces the required acidity for peat formation. On blanket bogs peat can build up to about 2-6m depth.
Much of the blanket bog on the Slieve Aughties is designated for nature conservation as a Special Protection Area because of the huge value of this habitat for rare and threatened birds including birds of prey such as the hen harrier and merlin.
The second type of bog found in east Galway, raised bogs, are mainly found in the midlands but there are several good examples in east Galway in the Kilimor areas (some of which are designated for nature conservation), and north-east Galway. Raised bogs form in lake basins over thousands of years. Plants that grew in and around the lakes fell to the bottom of the lake when they died. This dead plant material accumulated over time infilling the lake and forming what is known as a ‘fen’ peatland. Once the bog moss, Sphagnum, invaded the peatland it acidified the environment, slowing down decomposition rates further, and bog peat started to accumulate more rapidly. Raised bogs can have a considerable depth of peat (up to 12m!) as many of them started to form soon after the end of the last ice age, 10,000 years ago. This type of bog is now very rare in the rest of Europe.
Bogs are one of Ireland’s most special habitats due to their huge value for nature conservation. We have some of the best bogs in the world! Bogs have a deep-rooted cultural significance due to our long reliance on turf for fuel. Bogs also play an important role in flood control, maintaining water quality and storing carbon within the peat. Raised and blanket bogs are fabulous places to explore due to the abundance of weird and wonderful wildlife and the beautiful peatland vistas.
Peat is wet, acidic and very nutrient poor and so the plants that grow on bogs have to be able to survive harsh conditions. Examples of common bog plants include: heathers (ling, cross-leaved heath), sedges, insect-eating plants (sundew and butterwort), bog asphodel and bog cottons.
Several rare and threatened birds overwinter or nest on bogs in south-east Galway. e.g. golden plover, red grouse, merlin, hen harrier. The heather provide excellent cover for birds. Red grouse is on the increase in the Slieve Aughties due to local conservation efforts.Other commonly seen birds on bogs include meadow pipit and skylark.
A variety of bugs are found on bogs including many spiders, slugs, dragonflies and damselflies. One of Europe’s rare butterflies is found on peatlands in south-east Galway, the marsh fritillary butterfly
Frogs, hare and foxes can also be seen foraging on bogs. We take frogs and hare for granted in Ireland where they are quite common but they have become quite rare in other European countries due to loss of habitat and persecution.
Woodland cover in Ireland today is very low (c. 1.9%) when compared with the rest of Europe but County Galway has the second highest cover of woodland in the country. Much of this woodland is in the south and east of the county, in and around the Slieve Aughties. Several of the native woodlands found in south-east Galway are of high nature conservation value and as such have been designated as Special Areas of Conservation or Natural Heritage Areas e.g. Coole Park and Garryland, Gornacarnaun, and Derrycrag. These special areas are havens for wildlife and wonderful places to walk and explore.
Native woodlands greatly enhance our landscapes, they provide a renewable resource, act as carbon sinks, and they are extremely important for wildlife.
Native woodland tends to have high biodiversity value because the different layers within the woodland (e.g. canopy trees, shrubs, ground flora) provide a wide range of habitats for wildlife, and because of the lack of disturbance (e.g. compared with a grassland which undergoes regular mowing or grazing!).
Trees are big and live for a long time! They, therefore, provide a considerable resource for wildlife (food and shelter), and stabilty due to their long lifespan. Some woodland creatures and plants like to live high up in the canopy where there is lots of light and they are safe from predators or grazers; others prefer the humid, shady environment of the forest floor. A mature oak tree is often festooned with ferns, lichens and mosses and provides a rich source of food and shelter for birds, small mammals and insects.
There are several different types of woodland found in east Galway including sessile oak woodland with holly and birch found on acid soils (on Red Sandstone in the Slieve Aughties), pedunculate oak woodland with hazel and ash on limey soils (on Limestone), wet willow and alder woodland along rivers and around lakes, and bog woodland on cutover bogs.
Native trees commonly found in woodlands include sessile oak, pedunculate oak, ash, holly, hazel, rowan, elm, hawthorn and spindle. Wet woodlands along rivers and around lakes are often composed of alder and willows.
Common woodland flowers include lesser celandine, wild garlic, pignut, wood anemone, wood sorrel, bluebell, lords and ladies.There are also a huge array of woodland fungi, mosses, ferns, and lichens.
Many creatures love to live in woodlands; red squirrel, pine marten, birds (e.g. tree creeper, blue tit, chiffchaff and many more), bats, badgers, and a multitude of invertebrates (e.g. beetles, woodlice, spiders)
Hedgerows are like mini-woodlands winding their way across the countryside. Like woodlands they provide food, shelter and cover to wide range of wildlife. The linear nature of woodlands criss-crossing through agricultural landscapes means they are invaluable for birds (e.g. dunnock, robins and wrens), insects (e.g. ringlet, speckled wood and meadow brown) and small mammals (e.g. stoat, badgers and hedgehogs) as they provide corridors to move from one habitat to another. Many of our countryside birds nest in hedgerows.
There are a variety of habitats found along the coast of south Galway. These include small areas of saltmarsh, muddy, stoney and rocky shores. This coastline is of high nature conservation interest due to its importance for birds and other marine life. Galway Bay has been designed as a Special Protection Area for birds (known as the Inner Galway Bay SPA), and as a Special Area of Conservation because of marine species and habitats of interest (Galway Bay Complex SAC).
Coastal areas provide numerous opportunities and resources for recreation. They are often highly scenic and wonderful places to walk and explore. Coastal habitats are also of huge importance for wildlife, with a mix of marine and terrestrial species.
Salt marshes occur in sheltered bays and stretches of coastline. These marshey areas have a particular vegetation growing on the sandy, muddy or peaty sediments that are waterlogged and/or periodically submerged by the sea. The plants found in a saltmarsh (e.g. salt marsh grass, sea plantain, sea thrift and sea aster) have to cope with extreme environmental conditions because they are periodically inundated with salty water resulting in waterlogging and wide extremes of salinity. Saltmarsh sediments are often relatively nutrient-rich and therefore they provide a habitat for numerous invertebrates and molluscs.
Much of the shoreline from Kinvarra to Oranmore is a mix of rocky and stoney shores. A wide range of algae, molluscs and invertebrates can be found along the shore providing rich pickings for coastal birds and otters.
Grassland of nature conservation interest includes unimproved pastures and meadows (i.e. those not ploughed or fertilised). They are usually on marginal sites, with poor soils and are of low agricultural value- too stoney, too steep or too wet. These grasslands can be very species-rich and highly attractive. They do require some management, however, to maintain the nature conservation value i.e. moderate grazing or mowing early and late in the season. Without some management, grasslands can become rank with a few tall grasses dominating the sward, or invaded by scrub.
South and east Galway has some grassland areas of high nature conservation value - on the dry soils of the eskers or on thin, stoney soils over limestone, or the wet soils along the Shannon, the River Suck other watercourses.
These natural grasslands are often very attractive and greatly enhance local landscapes. Wet grasslands and callows also act as sponges, holding water, and therefore are important for flood control.
Dry calcareous grassland is found on thin limey soils often in and around exposed limestone often in south Galway. Eskers are a feature of east and north-east Galway and where they haven’t been ploughed or fertilised, species-rich esker grassland occurs.
Common plants for both include thyme, lady’s bedstraw, bird’s foot trefoil, early purple orchid, thyme and quaking grass. The rare green-veined orchid has been recorded on eskers in the county.
Wet grassland and callows occur around lakes and rivers, in floodplains and in areas with poor drainage. Often considered as waste areas they can have huge interest for wildlife:
Wet grassland plants include many large and attractive flowers e.g. purple loosestrife, meadowsweet, yellow flag, cuckoo flower, and ragged robin. Callows tend to have a variety of tall grasses and reeds, and many tall herbs. Corncrakes nest in the long grass of callows. Unfortunately they have become extremely rare in recent decades. Many birds use wet grasslands for nesting or forage including birds that are internationally rare lapwing and snipe. A multitude of invertebrates can be found in wet grasslands e.g. the rare marsh fritillary butterfly, and numerous different types of snails, dragonflies, damselflies etc.
Turloughs are more or less unique to Ireland. They are temporary lakes that are usually dry in the summer and wet in winter. Turloughs are a feature of karst limestone landscapes such as found in south-west Galway around Gort and Kinvarra. Turloughs are flooded by rising groundwater in winter and often grazed in summer. The extent of the flood level in a turlough can often be seen by the presence of a black moss around the edge of the flood zone. Turloughs that have woodland on their edge often have trees with black rings of moss on their trunks, 1-2m off the ground showing the average flooding depth in that area! Coole Park has plenty of examples.
Turloughs often have zones of vegetation around the central wettest point, depending of the extent, duration and depth of flooding. Turloughs tend to have a mosaic of habitats including wet grassland, marsh and fen, open water, dry grassland, woodland and limestone pavement. Due to the generally shallow water level and full vegetation cover turloughs provide a very valuable habitat for over-wintering waterbirds.
Many turloughs are of huge birdwatching interest (e.g. Rahasane) swans (mute and whooper), tufted duck, goldeneye, lapwing etc. They often have a rich invertebrate fauna due to lack of fish including some rare species of water flea and fairy shrimp.
Turloughs contain a range of plants depending on the extent, depth and duration of flooding. Some turlough plants are true aquatics e.g. water plaintain; others can tolerate wet soils and waterlogged conditions e.g. silverweed and while others don’t mind inundation during winter but like dry conditions during the growing season.
There are several beautiful lakes in south and east Galway, many of which are hugely important for nature and wildlife, as well as highly valued for recreation and as water sources. Some of these lakes are very popular with anglers and healthy fish populations usually reflect good water quality. Some lakes, such as Lough Rea, are home to several interesting types of rare algae, stoneworts, which like the calcareous, clean and clear waters.
Lakes are often important for waterbirds: nesting birds in summer (e.g. Coot and Swans) and birds that come to spend the winter here (e.g. Shoveler duck and Golden eye).
Lakes that have good water quality and a range of habitats around their edges are most important for wildlife as they provide a range of food, and places to find shelter and cover. Lakes usually have wet terrestrial habitats around their edges and any inflowing or outflowing streams, such as areas of wet woodland, reed swamp, fen, wet grassland and marsh. These habitats are where many birds like to nest or overwinter where there is good cover, as well as, food. Otters are shy creatures that particularly like good cover and healthy fish populations to feed on.