O'Rkilly — On the Waste of the Coast of Ireland, ^c. 161 



entombed in blown sand, as noticed by the late Mrs. Craik (in an 

 ' Unknown Country ' : an illustrated account of a toui' in Donegal). 



" Fanad District. — Examples of raised beaches are found all round 

 the northern coast from Ballymastocker Bay, on Lough Swilly, to 

 Mark's Point at the ' Narrows ' on Mulroy waters. 



"At Ballymastocker Bay a fine example maybe seen of an old 

 sea-cli:ff, 1000 feet inland from the present tidal flow. It is semi- 

 circular, and about 50 feet high ; the space between it and the sea is 

 filled with sands which, in places, are becoming cemented together. 

 Evidence of a raised beach can also be seen at Sessiagh Bay, and to 

 the south at Doaghmore Strand." 



Memoir, Geological Survey of Ireland, Sheets 22, 23, 30, and 31 

 (in part), 



(p. 7.) — "The district described in this memoir comprises the 

 south-westeiiy portion of the county Donegal, lying to the north of 

 Donegal Bay, and stretching along its western margin into the 

 Atlantic Ocean. Along its coast-line it is indented by numerous bays 

 with intervening headlands." 



(p. 10.) — " Sea-cliffs and Headlands. — The promontory of Banagh 

 generally presents a bold and rock-bound coast to the Atlantic, deeply 

 indented with bays and gullies, and often rising in cliffs several 

 hundi'ed feet above the surface of the ocean. Along the southern 

 shore of Loughros Beg Bay, the quartzite cliffs rise from the ocean in 

 a steeply sloping wall, 500 feet in height ; and some distance further 

 west, under the summit of Slieve Tooey, a nearly vertical wall of the 

 same rock descends a thousand feet from its edge to the surface of the 

 waters. At the head of Tormore Bay, still further west, the cliffs are 

 almost equally lofty and steep ; and all along the coast to Glen Head 

 they break off with faces several hundi'ed feet in height. Glen Head 

 is a remarkable cliff, almost vertical, with a descent of 600 feet, 

 surmounted by a tower, built as a watch-tower in the time of the 

 Spanish Ai-mada. Tlie long ridge of quartzite, which bounds the 

 valley of Glencolumbkille on the south, here breaks off abruptly ; 

 and along with the cliffs terminating at Doon Point, encloses a little 

 bay, at the head of which are masses of shingle, piled up by the 

 powerful Atlantic waves when impelled by westerly winds. The 

 force of these waves must be sometimes prodigious ; but their 

 destructive effects on the quartzite rock, which is natui'ally brittle, 

 are somewhat lessened by the occiQ'rence of intrusive sheets and dykes 

 of epidiorite, which help to bind together, as with bands of ii-on, the 



02 



