Stratigraphical Geol(\i^y. 9 1 



the raised beaches and the upjier estuarine clay are con- 

 temporaneous.^ 



/Raised beaches. 

 I, Upper estuarine clay. 

 Lower estuarine clay. 

 Submerged peat. 

 Sands and gravels. 

 Boulder clay. 



EsTU.ARiNK Cl.ws are found under much of the low- 

 lying area of the city of Belfast. The various works done 

 by the Harbour Commissioners have exposed thick beds 

 of these clays. In their lower portions they are of a 

 littoral character, but in the upper portions are found many 

 shells which live in depths of five to ten fathoms. These 

 clays have yielded an abundant fauna, many of the species 

 attaining remarkable dimensions. The deposit is a tough 

 blue clay ; under water it readily becomes a pasty mud ; so 

 that in the city, where the clay occurs, piles about forty feet 

 long have to be used in forming foundations. 



Similar deposits are found in Larne Harbour, notably at 

 Magheramorne, and in almost all the bays in the north-east 

 of Ireland. - 



The peat bed contains remains of the Great Irish Deer, 

 well-preserved plant remains, such as hazel, alder, oak, 

 sedges, etc., and elytra of beetles. Resting on the peat is the 

 lower or Scrohicularia zone of the estuarine clay, with a 

 littoral shell fauna ; the upper estuarine clay deposited in 

 deeper water yielding Thraria convexa. 



The sands and gravels of the Lagan valley are in many cases 

 rede[)osited glacial deposits, owing their present position to 

 the damming up of the drainage systems at the close of 

 glacial times. Near the Ormeau Bridge fine sections have 

 been exposed in the Annadale and other brickworks, while 

 the eskers at Lisburn are the remains of englacial deposits 

 contemporaneous with the gravels and sands of the valley 

 above noted. 



' Pr.-\egkr. — Raised Beaches of N. E. of Ireland. Proc. koyal Irish 

 Academy, 3rd series, vol. iv. No. i (1897). 



- Kstuarine Clays of the N. E. of Ireland. Ibid., vol. li, No. 2 (1892). 



