THE GLACIAL DEPOSITS OF NORTHERN PEMBROKESHIRE. 59 
Contemporaneous volcanic rocks and intrusive sheets of diabase occur in the district 
between Fishguard and Newport, and further south in the Precelly mountains strips of 
felspathic rock are indicated on the Survey maps. 
East of Newport the igneous rocks die out. 
Blown sands are heaped up at places on the coast, and are generally full of land 
shells. To the east of Whitesand Bay they rise to heights of 150 feet and are pro- 
longed inland for nearly a mile, giving rise to the tract known as “The Burrows” or 
““Towyn.” They are also seen at Abermawr, and cover an extensive area at Newport, 
and again at the mouth of the Teifi, where they form dunes known as the ‘“ 'Towyn 
Warrens.” 
Towards the western end the country, as seen from a height, presents the aspect of 
a flattened tableland or plateau, having for the greater part of its extent no great 
elevation above sea-level, but here and there having rocky knobs and masses jutting 
out, especially towards the western and north-western extremities of the promontory. 
The view, as seen from one of the hills on Ramsay Island, suggested to Sir ANDREW 
Ramsay that in this part of Wales we have the remnant of an old plain of marine 
denudation, which is continued into Cardiganshire and further inland. The rugged 
masses of Carn Llidi and Pen Berry, which rise so boldly just east of St David’s Head, 
and have relatively the appearance of considerable mountains, only attain heights of 
595 feet and 576 feet respectively. Further east the rough eminences which stand 
out so prominently on Strumble Head are mostly under 600 feet in height—Garn Gelli 
alone exceeding that limit and attaining 625 feet. Garn Fawr, famous for the remains 
of ancient fortifications there found, is just short of 600 feet high. 
Between Fishguard and Newport is a ridge of high land, reaching elevations of over 
1000 feet at Mynydd Melyn, Mynydd Caregog, and Carn Ingle. To the south of 
these rise the Precelly mountains, which have a somewhat smooth outline and attain 
heights up to 1500 feet. From Newport to Cardigan the country is hilly, but not 
mountainous—the highest point being Pen Creigiau, which is 642 feet above sea-level. 
The highest ground is formed of diabase and other intrusive igneous masses ; the 
volcanic rocks occupy ground above the average level, while the low-lying ground 
consists of the more easily denuded slaty and shaly beds. 
Passing from west to east, the land generally becomes more hilly, and the higher 
grounds from Newport to Cardigan are composed of hard sandstones or arenaceous slates. 
The main streams of the district occupy pre-glacial valleys, and have cut their way 
through the drift which once filled them. The estuaries of the rivers Solva, Alan, and 
the Gwaen are ria-like in appearance, and it is probable that an arm of the sea once 
extended for some way up the lower course of each; for the estuaries are trench-like, 
with steep rocky walls on either side for a considerable distance inland, and it is hardly 
conceivable that these have been cut out altogether by the action of the streams. 
On the northern coast there are two peninsulas of a very peculiar character, for 
they are separated from the mainland by trench-like valleys, which, though now never 
