Stratigrapliical Geology. yj 



being carried on, and the fine sections at one lime exposed 

 in the quarries are now covered with water, and much of the 

 rock in the district is covered with boulder clay. That 

 the Carboniferous limestone covered a considerable area of 

 the adjoining Strangford Lough seems to be indicated by the 

 numerous erratics of Carboniferous limestone found in the 

 boulder clay to the south of this locality. The rock surfaces 

 also, when cleared of their covering of boulder clay, exhibit 

 well-marked glacial stride. 



The fossils obtained, when good sections were exposed, 

 were of remarkably large size. Productus gtganteus, Ac- 

 iinoceras giganteum, Aihyris ambigna have been recorded. 



Another small patch of Carboniferous limestone occurs at 

 Cranfield Point, the most southerly point of County Down. 

 It is evidently a continuation of the fine development of 

 marine Carboniferous limestone found on the opposite shores 

 of Carlingford Lough. 



Triassic System. 



Rocks of this age occur in both Antrim and Down. They 

 form the basement rock of the Lagan valley from Belfast 

 to Waringstown. They are widely exposed along the north 

 shores of Belfast Lough, where they are lost under the sea 

 on one hand, but extend right up to the foot of the basalt 

 escarpment, giving rise to gently undulating uplands. On 

 the south shores of Belfast Lough they extend as far as Cultra, 

 and are there found resting unconformably on the edges of 

 uptilted Lower Silurians. A wide belt of Trias extends from 

 Belfast down the Dundonald valley to Newtownards and 

 along the shores of Strangford Lough to Greyabbey. 



The Trias in this district has representatives of the Lower 

 Trias or Bunter, and the Upper Trias or Keuper. 



BuNTER. — The English Bunter has been subdivided into 

 upper variegated sandstones, pebble beds or conglomerates, 

 and lower variegated sandstones. 



From lithological similarity, the sandstones of the Lagan 

 valley have been referred to the upper variegated sandstones 

 of Bunter age ; the pebble beds of the English series as 

 found in Cheshire not being found in our district, unless 



