Excursion 5: Eilean Thuilm and Sgor Sgaileach—reptile bones and a columnar sill

(Route map 5)

More spectacular views, impressive columnar cliffs, and a chance to find bones of a plesiosaur. This is a strenuous walk, involving a steep grassy climb followed by a descent over rough landslipped ground without a marked path.

Bealach Thuilm

The best access to the north-east corner of the island is from Howlin [NM 4789 8951], the last and loneliest house in Cleadale. Go past the house and bear right, following a track through bracken above the boggy ground to the west. A stile leads to the grassy approach to the low pass of Bealach Thuilm [NM 4769 9053]. There is a splendid view to the south, with the two bays, Laig and Camas Sgiotaig, the fields of Cleadale, and the long ridge of the Sgurr pitchstone forming the southern skyline. The hillock of Guala Mor, to the west of the col, is composed of morainic and landslip debris from the last glaciation.

As you descend to the north, the scene changes dramatically. The green fields of Cleadale and the white sandy bays are lost from view. The north-facing cliffs are dark basalt in their upper part, with sandstone beneath; the shore shows black basalt sills, and the slopes between are a jumble of landslip debris. It is a remarkable change from one of the sunniest scenes in the Hebrides to one of gloomy grandeur. The Cuillin of Skye stand proud to the north. The contact between the Valtos Sandstone and the basalt represents a long period of erosion, for the higher Jurassic strata seen around Laig are absent here. Pick your way among the tumbled landslips of Talm and descend towards Eilean Thuilm.

The shore at Eilean Thuilm

The storm beach [NM 4823 9116] is where, in 1844, Hugh Miller found pebbles and boulders of a distinctive red-weathering shelly limestone, in which he discovered bones of a species of small plesiosaur. Bones may still be found occasionally. Recognisable teeth and scales of fish, as well as numerous small shells of gastropods (snails), are common. Fossiliferous pebbles may also be found in the prominent raised beach, which is cut into old landslip deposits and is being partly covered by younger ones. Try not to disturb the terns which often nest near here, and look out for seals in the water and on the island; in calm weather you may hear them singing.

The Sgor Sgaileach columnar sill

Eilean Thuilm is made of quartz porphyry (page 21), which also makes the red- weathering columnar cliffs of Sgor Sgaileach that form the north-eastern extremity of Eigg. Sloping surfaces just west [NM 4840 9130] of the headland give cross-sections of their polygonal plan. The north- and east-facing cliffs, with several caves, show columns standing vertically, cut by thin basaltic sills. The columns are impressively broad and regular, evoking ruined temples where fallen.

Cliff erosion

The northern basalt cliffs give a fine opportunity to examine the various means by which cliffs retreat. In places, screes form from small detached rock fragments. At others, large blocks record catastrophic rock falls. The locus of scree formation has evidently changed over comparatively recent time, for all that we can now observe post-dates the last glaciation. The largest process of cliff recession is the formation of rotational landslips, best seen on the east coast (Excursion 6). A combination of these processes has formed the jumbled topography of Talm.

Return to Cleadale by climbing back to Bealach Thuilm and thence to Howlin.

Excursion 5 extension: Beinn Bhuidhe

Those with remaining energy can climb the heathery slope above the col, which here gives access to the Beinn Bhuidhe plateau, between the inaccessible cliffs above Cleadale to the south and above Talm to the east. There is a zigzag path, which led to former peat diggings on the plateau. Follow the western edge of the plateau, above the basalt cliffs, to the summit, being rewarded with even more spectacular views, and alpine flowers such as Dryas octopetala and Silene acaulis. Return the same way or continue southwards, eventually regaining the road beyond Cuagach, but the going is very rough.