19 f I- Stewart. — Fhcct^iations of Sea-leveL 19 



twenty-five feet higher than at present, or in other words 

 the sea-level was twenty-five feet lower. This may be 

 called the era of the submerged peat. 



(2). There was a period which I shall call the Scrobicularia 

 period, when the land had suffered depression, and stood 

 at a level a few feet lower than at present. 



(3). A renewed depression, when the land sunk still 

 lower ; this subsidence I estimate to have amounted to 

 some forty feet at least below the present level or sixty -five 

 feet below the original. This may be styled the Thracia 

 convexa period, that shell having then lived in abundance 

 where our present quays stand. 



(4). A period of elevation when the many raised beaches 

 that stud our coasts were brought up, and the present shore 

 lines established. 



First : — As to the times of the submerged peat and 

 forests. Numerous"* peat -bogs now covered by marine 

 accumulations testify to a former high level of the land. 

 Peat, as you know, does not grow in the sea, nor in any 

 position in which it will be washed by the tide at high 

 water ; consequently when you find it below high water 

 mark the conclusion then is inevitable that the relative 

 level of sea and land must have altered, and thus the 

 peat that grew above the reach of the sea now comes to be 

 below it. Beds of peat are found underneath the town [of 

 Belfast], and under the slob in the ground reclaimed by the 

 Harbour Commissioners at the rear of the Queen's Quay, as 

 you go to the People's Park (so-called), also at Sydenham 

 and further along on the Co. Down side of the bay at Bally- 

 holme. These old mosses are all below high water ; that 

 at the Bangor shore can only be seen at extreme low water. 

 On the opposite shore too, at Carrickfergus, is a notable 

 instance, where not only peat occurs but even a forest of 

 ancient trees or bushes, mostly Hazel and Alder, mixed 

 with such marsh plants as flags, sedges and rushes, and 

 extending more or less for about a mile along the shore. 

 Those members of the Naturalists' Field Club who attended 

 the field meeting at the Giant's Causeway in June, 1868, 

 will remember examining a peat bed that crops up between 

 tide -marks near Portrush. They had on that occasion the 



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