Most of the extrusive igneous rock in Mull and the other islands is basaltic lava of one type or another. However, there are also pyroclastic rocks to be found. Volcanic conglomerates are found throughout Mull, the best examples being at Barrachandroman in SE Mull. There are also localities where volcanic ash can be found. The main localities are:
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Staffa
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Carsaig Arches
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Rubha na h-Uamha (near the Fossil Tree)
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Lagganulva
With the exception of Lagganulva, these localities are quite remote and difficult of access. The Lagganulva ash deposit is found at Camas an Lagain and is very close to the road. Very easy to get to! The ash is also seen at the Eas Fors waterfall which lies a short distance to the north west, further along the coast and well worth a visit.
Camas an Lagain, on the shore, looking NW towards Treshnish Point
The picture above shows the ash which makes up the rocky shore, with fragments of varying sizes embedded in it. However, one of the really outstanding features about this ash is how it has been altered by th thermal effects of several dykes of the Mull Swarm which cut across it:
In the above picture a dyke is clearly visible running NW-SE through the ash. The country rock, in this case the ash, has been reddened by the Field Trips metamorphism from the hot dyke when it was intruded. The colour is really obvious in the field.
The pictures below show the effect in more detail:
