214 Cotr—On the Geology of Shieve Gallion, in the County of Londonderry. 
The accompanying sketch (Pl. xt.) will serve to show the general character of 
the range. An old writer has spoken of the Sheve Gallion ‘‘ mountains,” a fact 
which may account for the same name being given to both the principal summits. 
The one styled here ‘‘Slieve Gallion North” is 1623 feet above the sea, and is 
the ‘ Slieve Gallion Carn” of Survey Memoirs. The southern summit reaches 
1735 feet; and the intervening moorland, covered for the most part with deep bog, 
does not sink lower than 1450 feet at the col above the White Water. 
Between this passage and the dome of Drummuck hes the most picturesque 
and broken portion of the range, the rocks cropping out in terraces and bosses, 
with the steep scarp of basalt and chalk rising as a background in the north. 
Elsewhere, rock-exposures are comparatively few; and even the streams that have 
carved out deep hollows have at one time been choked with débris, through which 
they are now cutting little canons. The red stainings of iron-ore that permeate 
these granite taluses render the ravines conspicuous at a distance; and they seem 
early to have attracted the attention of the peasantry. The first engineering 
operations on Slieve Gallion are attributed to a sister of Callann Mor,* who tried to 
remove the mass which stood between her and a friend in the county of Tyrone. 
But all the men who worked for her ‘‘ got a sore in the fingers”; and it was said 
that “anyone that would attempt to cut away the mountain would take the same 
sore.” The “Red Bank” is shown as the place of these prehistoric efforts; and 
it is in reality probable that iron-workings were attempted here in very early days. 
While the south-eastern face of the range descends into a pleasant land of 
wooded slopes and close-set farms, due to the Carboniferous and Triassic strata 
round Moneymore, the view north-westward from the col is one of utter contrast. 
The region of undetermined schists stretches from Sheve Gallion in that direction 
into Donegal; and the wild masses of the Sperrin Mountains form a highland 
rarely traversed. Between their base and the ridge on which we stand, the moor 
is almost continuous ; but here and there a lakelet lies gleaming among the little 
hills of gravel, which rise as strange cones above the broad curvings of the foot-hills. 
The bold road which climbs so steeply from Desertmartin, and which runs along 
the north-west terrace of the mountain, descends again on the south by the glen of 
Lissan, after commanding a series of superb and desolate moorland-views. It has 
its counterpart on the sunnier side of the range in the road from Dirnan to Tintagh 
and Iniscarn; and the frequent and well made branches, by which the peat-carts 
go up and down, afford easy access to the mountain. 
Such is Sieve Gallion—an isolated ridge, a kind of hog’s-back, indented by four 
great combes on the south-east, and by one main valley, that of the White Water, 
* John O’Donoyan, ‘‘ Letters containing information relative to the Antiquities of the County of 
Londonderry, collected during the progress of the Ordnance Survey in 1834.” MS., p. 225. R. I. 
Acad. Library. 
