Rocks at Dunquin on the Dingle Peninsula

The Blasket Islands are deserted now but at one time the small pier at Dunquin was a lifeline for the small island community. It is hard to imagine the hardships of their existence and the way they would have navigated in all weathers across the short stretch of water to the mainland of the Dingle peninsula in tarred canvas-covered open boats called curraghs. For the islanders wanting to buy or sell goods, needing a doctor, having to attend church, confession, christenings, weddings, or funerals, or to visit mainland friends and family, Dunquin was an important landing place. The very basic, even primitive, life of the islanders is movingly and simply told in The Islandman by Tomás O’Crohan  who lived and died on Great Blasket Island (1856 to 1937). Nowadays, it seems to be mostly small boats that launch from the pier to ferry tourists to the uninhabited islands .

Dunquin harbour not only has this important historical association but it is also a noteworthy geological location. Walking down the steep, zig-zag path from the stone-walled green fields above to the beach and pier below, there are great views of the cliffs to the north and south of the harbour. It is a transition zone between two major geological periods – where a predominantly marine environment changed to a mainly terrestrial one due to vascillating sea level relative to the land. It is the location where yellow marine siltstones belonging to the Drom Point Formation of the Silurian Dunquin Group lie next to the reddish, purplish, and greenish sandstone strata of the Silurian/Devonian Dingle Group which are terrestrial in origin.

The cliff faces seem to be striped in contrasting subtle hues. The rock layers are steeply angled now following earth movements over the many millions of years since they were originally laid down in a horizontal position. Odd circular or spherical formations can be seen in some layers. The bedding plane of one outcrop next to the pier has a roughly polygonal pattern of drying mud cracks preserved in the stone. Curving veins of quartz cut across the strata to the south of the harbour.

Altogether a very good place for rock enthusiasts and well worth a return visit. Next time I would like to take a boat trip to the Blasket Islands where (on Inishvickillane at least) the rocks are mainly volcanic tuffs and lavas.

REFERENCES

O’Crohan, Tomás,  1937 The Islandman, Oxford University Press, ISBN 978-0-19-281233-9, re-issued 2000.

Horne, Ralph R., 1976, Geological Guide to the Dingle Peninsula, Geological Survey of Ireland Guide Series No. 1, Minister for Industry and Energy, Geological Survey Office. Reprinted 1999.

Rocks at Clogher Bay 3

Silurian rock at Clogher Bay in Dingle

View of cliffs at Clogher Bay with human figure for scaleThis is the third in a series of photographs of Silurian rocks from Clogher Bay. A brief examination of the literature indicates that the rocks in these pictures belong to the Drom Point Formation which has accumulated to a depth of 300 metres and is part of the Dunquin Group of Silurian Period strata in Ireland. The Drom Point and Croagh-marhin Formations consist of shallow-marine, fossiliferous siltstones and very fine to fine grained sandstones.

Rock colour and texture boulders and cliff in Silurian Period silt stones and sandstones from the Drompoint Formation in Dingle

Rock colour and texture with Chondrites trace fossils in Silurian Period silt stones and sandstones from the Drompoint Formation in Dingle

Rock colour and texture in Silurian Period silt stones and sandstones from the Drompoint Formation in Dingle

Rock colour and texture in Silurian Period silt stones and sandstones from the Drompoint Formation in Dingle

Rock colour and texture with preserved sand ripples in Silurian Period silt stones and sandstones from the Drompoint Formation in Dingle

Rock colour and texture in Silurian Period silt stones and sandstones from the Drompoint Formation in Dingle

Rock colour and texture in Silurian Period silt stones and sandstones from the Drompoint Formation in Dingle

Rock colour and texture in Silurian Period silt stones and sandstones from the Drompoint Formation in Dingle

Rock colour and texture in Silurian Period silt stones and sandstones from the Drompoint Formation in Dingle