Outdoor Education - Highland Perthshire

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Limestone Pavement

The limestone pavement on the slopes of Schiehallion is a site of special scientific interest. (SSSI). It is a very old limestone (600 million years old) - It is called Dalradian Limestone. Unlike the Carboniferous limestone of the Pennines it does not contain fossils. The calcium carbonate was precipitated onto the sea floor.

Limestone dissolves in acid rain and the grooves formed (called grykes) can be up to six feet deep. The high areas in between are called clints.

Some plants like to grow near limestone, as they like alkaline soil. These include Rock Rose, Thyme and Strawberry.

Some woodland plants are still able to grow in the grykes where they are protected from grazing by sheep. At one time most of the highlands were covered by Caledonian pine forest but most of the forest has now disappeared. The flowers that grew in the forset may persist where they are protected from grazing animals such as sheep and deer. This is what has happened on the limestone pavement where the grykes are deep enough to prevent the plants from being eaten.

The woodland plants include - Herb Robert, Herb Bennet, Ivy, Wood Sorrel, Wood Anemone, Rowan, Birch, Dog's Mercury.

The Dalradian Limestone Pavement - the grykes are the dark areas and the clints are the upstanding areas.

A biotite schist erratic can be seen sitting on top of the limestone pavement. This is a rock that has been transported here by ice from elsewhere. It shows interesting weathering called honeycomb weathering. The mineral biotite contains iron and this weathers quickly to produce pits in the rock.

Dunalastair Water can be seen in the background

The view along the Schiehallion Road towards Aberfeldy. Loch na Daihm is on the left
Birds foot Trefoil.
Butterwort - this is an insectivorous plant which grows in boggy areas. The rosette of leaves at the base contain liquid which traps the insects and then enzymes digest them before the plant absrbs the nutrients.
Butterwort
Chickweed wintergreen - a woodland flower
Cotton Grass - grows in boggy areas
Dog's Mercury - a woodland plant
Fern and Herb Robert
Herb Robert
Herb Robert
Herb Robert
Ivy
White lichen - lichen is an indicator species for pure air.
Ling heather
Milkwort
Mountain Pansy
Limestone quarry
Limestone quarry
Rock Rose - a plant that likes to grow near limestone
Rose Bay Willow herb
Rowan Sapling - protected from grazing
Snail shell - snails are common as they can absorb calcium and use it for growing their shells. Their shells are made of calcium carbonate.
Wild strawberry - a plant the likes to grow near limestone.
Tormentil
Milkwort and tormentil
Violets
Wood sorrel - a woodland plant - protected by the grykes.

Rannoch Net