36 Fingal and East Coast. 



At the head of the little vale, and on the opposite side 

 of the streamlet referred to, the same fossiliferous and 

 ealcareo-argillaceous strata present themselves, forming 

 the side of a gently shelving hill. Greenstone soon suc- 

 ceeds ; but between this and the stratified rocks numerous 

 calcareous springs issue, depositing more or less of lime 

 as they descend. At one place the deposit of calcareous 

 tufa is sufficiently important to have been veorked for 

 lime by Mr. Grant. As usual, it varies from very 

 porous, soft, and friable to hard, tenacious, and compact : 

 it is of a dull white colour, and contains numbers of a 

 land shell, appearing not to differ widely from a small 

 Planorhis now extant in Van Diemen's Land. 



Although the limestone itself does not crop out over 

 the fossiliferous clayey beds, it may fairly be presumed 

 that it exists here between these beds and the greenstone, 

 and that the calcareous springs which issue derive from it 

 their burden of calcareous matter. 



In a wild glen, about a mile and a half to the west of 

 this place, there runs a tiny rill or two, which have on 

 either hand perpendicular escarpments, disclosing the 

 whole sequence of beds from the vertical clay-slate to the 

 limestone. These are known as the Carlland Crags : 

 the dip of the seams is to the south east, at a small angle 

 from the horizon. 



The character of this gorge is remarkable. On ap- 

 proaching it, the hills on each hand fall back in graceful 

 slopes, rising by degrees into steeper acclivities, which 

 give place further on to precipitous rocks, with a varying 

 amount of debris, shelving down like artificial buttresses 

 to the edge of the rapid brook. From the point where 

 the rocks become precipitous, to that where the sub- 

 divisions of the brook trickle over the edge of the narrow 

 gullet, at its extremity, may be about 600 yards ; the 

 chasm may measure 150 to 200 yards across ; and where 

 the channel is lowest its depth may be 220 feet. 



