Geology 



A careful search from the foot of Coal Hill to that 

 of the Permian escarpment failed to yield any trace of 

 the lost seams, and on making a true-scale section, that 

 is, a section in which the vertical and horizontal scales 

 are the same, we saw that the Bottom Seam would not 

 reach the level of the plain for some distance to the 

 south of the escarpment (Fig. 20). 



If the dip of the Coal Measures remained constant 

 at 10, the Permians dipping at 12- 15, there was little 

 likelihood of recovering the seams beneath the uncon- 

 formity, but if the dip of the older series increased 

 towards the south, they might yet be preserved beneath 

 the covering of newer rocks. 



>"^ * r\. 



FIG. 20. a, Permian ; , Coal Measures. 



Thus we were unable to give a favourable report as 

 to the possibility of finding further reserves in the ex- 

 posed area of Coal Measures, but we strongly advised 

 exploration by boring to the south of the escarpment. 

 After some demur on the ground of expense, the author- 

 ities at Lyell undertook to carry this out under our 

 supervision. 



We had now to consider the question of choice of a 

 site for our trial bore, and in this we naturally had to be 

 guided by the probable thickness of Permian and newer 

 rocks, which it would be necessary to penetrate before 

 reaching the underlying Coal Measures. 



The Permians dip at 3 in the valley of the West 

 River, and their base is at a level of 650 feet above the 



126 



