Please start by looking out to sea from the
campfire (map D3).
On your right, past Castle Duart, you will see
the Stevenson lighthouse at the South end of the
island of Lismore,
and on your left the
Under the sea between them is the Great Glen
Fault running straight through the Great Glen (Glen Albyn) and Loch Ness to Inverness and beyond.
This fault cut
into two blocks of metamorphic rock about 400 million years ago.
Much later, Mull was thrown up right across the
fault by volcanoes round Loch
looks like a Pictish sculpture but is part of a “cone sheet” – see para 4
below -running under the campfire
(map D3) and re-appearing in front of the
The molehills are more recent.
Just to the right of the fault,
30 miles away, is Ben Nevis, with flat top
and shoulder this side.
To the North the cliffs are awesome.
To the right of Ben Nevis
you will see more Munros (hills over 3000 ft) than anywhere else in Scotland.
They are the stumps of the
up about the same time as the Fault.
The craig (map F5).
The force of the volcanic intrusion stood the
sedimentary limestone on its end.
If you start up the woodland track you will see
the limestone clearly on your left (map G4).
About 60 million years ago there
was a spectacular eruption of volcanoes along Scotland's
western edge, in St. Kilda, Skye, Rum, Ardnmurchan, Mull and Arran.
Look across to Morvern to see some of the
A big fault
cuts the hillside immediately opposite.
To the left is a plateau of volcanic basalt
lava, where in a SW wind, the waterfalls blow straight up in plumes of
At the centre and rear is very old metamorphic rock,
changed from other rocks by heat and pressure.
The right, parallel to the coast, is all
granite, igneous rock cooled beneath the surface, called “plutonic” after
the Roman God of the Underworld.
Huge bulk carriers come worldwide for this
quality granite from the quarry at Glensanda further up the coast.
The abseil (map F5).
The sea broke here at the end of the Ice Age
The volcanoes were in the centre
running SE from Loch Ba.
Ben More and other hills like Beinn Fhada and
Beinn Talaidh are all that remains of the caldera or cauldron from which the
As the surrounding land fell back toward the
centre of the empty caldera, concentric cracks opened and were filled with
“cone sheets” of igneous rock like granophyre.
Intrusive “dykes” appeared, typically in a
NW direction parallel with the Sound of Mull.
Later, more granophyre intruded into the
basaltic caldera, causing peripheral folding in the original “country”
rocks, rather like the ripples when a stone is thrown in water.
A dyke of columnar basalt, looking rather like
Staffa on its side (map G4)
You are actually standing on one of these folds or
The granophyre round here is so distinctive it
gets the special name of “Craignurite”.
It has intruded and shattered the limestone,
sedimentary rock of
calcium carbonate formed from
shells millions of years earlier.
We hope you agree that the grass in the field
has benefited from the fertility and drainage of the limestone.
and greensand beds with shell fossils (map G4)
During the Ice Age a major glacier came down the Great Glen Fault to meet
minor glaciers from Mull
At the end of the Ice Age, about 10,000 years ago, the
sea came to the base of the craig on which you are standing.
As the weight of the ice was removed, the land
rose gradually to its present level leaving a wave cut platform behind.