THE GLACIAL DEPOSITS OF NORTHERN PEMBROKESHIRE. 69 
shown. The bottom of the deposit is not seen, but as traced downwards the material 
becomes very sandy. It is ferruginous, and has a reddish colour. . 
The sands and gravels become more evident in the neighbourhood of Mathry. A 
little to the east lies a rugged mass of igneous rock known as Y Graig, and on the 
south side of this there is a newly dug pit, exposing 8 feet of pebbly gravel and 
gritty sand, with streaks of fine yellow sand. The deposit gets more sandy as traced 
downwards, but the bottom is not seen. A tendency to a rough bedding is shown in 
the section. At Pont Duan, north of the roadside, a very similar gravel-pit is seen. 
Pen Cnuc, at Castle Morris, marks the site of a mound of fine yellow sand, most of 
which has now been carried away. 
Gravel and sand is exposed, but only to a depth of 4 feet, in a field 200 yards north 
of Bridge-end, and again at Heathfield, south of the house. Further north, Tre-gwynt 
lies on sand and gravel, and much sand is seen between T're-gwynt and Trellys. 
Hast of St Nicholas Church the sands and gravels cover most of the land, as may be 
seen in pits in many of the fields. The writer employed a man to dig here in order to 
ascertain if possible the depth attained by the sand and gravel. At 8 feet the bottom 
was not reached, but the gravel became wet, and it is probable that the blue clay lies a 
few feet lower down, for it crops out in the moor below St Nicholas Church. The 
pebbles in the gravel-pit were all well rounded, and chalk-flints were seen. Gravels 
and sands seem to cover much of the ground on the Strumble Head promontory, but 
at places a yellowish earthy clay replaces them at the surface, though they may here 
occur with the clay. In a boring made for a well at Llandruidion farm sand was 
brought to the surface, in which comminuted shells were seen. The boring reached a 
depth of over 20 feet, and rock was not reached. 
In the farmyard at Tre-howell, near the northern extremity of Strumble Head, in 
sinking for a well, no sand was passed through—all was earthy clay ; but in a field 250: 
yards further north a sand-pit occurs, where 2 feet of fine yellowish sand are seen, 
covered by 2 or 3 feet of a loamy and somewhat stony clay. Mounds of gravel and 
sand occur on Caergowil, on the heights above Goodwick, and sections 7 feet deep are 
exposed. They are of the usual character. 
South and east of Goodwick and Fishguard deposits of sand and of gravel are 
frequently met with. They do not occur in the form of kames or eskers, but are found 
lying in the slopes of the minor hills, and sometimes spreading to the top. It would 
be almost impossible to map them, as their occurrence is so irregular and patchy ; they 
are apt to die out laterally in a sudden way, passing into clay or rubbly-drift. At 
many places they are overlain by an Upper Boulder-Clay. Perhaps the most 
interesting of all the sections is one seen in the Manorowen sand- pit, which lies 
in a small wood on the roadside, immediately south of the farm buildings, at a height 
of nearly 200 feet above sea-level, and two miles distant from Goodwick Bay. When 
visited a section of only 5 feet was seen, but means were taken to deepen it down 
to 12 feet. A somewhat diagrammatic view of this section is shown in fig. 1. 
TRANS. ROY. SOC. EDIN., VOL. XLI. PART I. (NO. 4). 12 
