288 PROCEEDINGS OF SECTION C. 



At Holt-Suthei'land and Heathcote the thickness of strata 

 between the cupriferous shale and the coal seams is almost identical, 

 being 440 feet. At Newington, however, on the Parramatta 

 River, the cupriferous shale is either on a different geological 

 horizon to that of the NaiTabeen Shales, or if it be on the same 

 geological horizon, there must be a complete change of dip 

 accompanied by a thinning out of the Narrabeen Shales, for the 

 following reasons : — The dip from Coal Cliff to Holt-Sutherland 

 is northerly, and between Heathcote and Holt-Suthei'land, the 

 amount of dip is about 1 in 38 = 139 feet per mile. Newington 

 is about twelve miles northerly from Holt-Sutherland, therefore, 

 supposing the surface levels to be the same, and that the northerly 

 dip continued at the same rate, the cuprifei'ous shales at Newington 

 should be 1,668 feet deeper than at Holt-Sutherland, but the surface 

 at Newington being about one hundred feet lower than at Holt- 

 Sutherland, the increase in depth would be 1,568 feet. At Holt- 

 Sutherland the copper shales were first struck at 1,764 feet from 

 the surface, therefore at Newington they should theoretically lie 

 at a depth of about 3,330 feet instead of 1,150 feet as is actually 

 the case. There must, therefore, either be an upper cuprifei'ouji 

 shale horizon belonging to the Narrabeen Shales, or if these cupri- 

 ferous shales at Newington are on the same geological horizon as 

 those at Holt-Sutherland and Heathcote there must be a reversal 

 of dip from north to south between Holt-Sutherland and New- 

 ington. If the latter is the case, it may be due to a gradual 

 rising up in this direction of the old floor on which the rocks of 

 the Coal-measures and the succeeding formations were deposited. 

 Strong evidence of this is afforded by the existence of the old 

 inlier known as Waimalee Hill at Prospect, near Parramatta. 

 The Rev. W. B. Clarke considered the Waimalee Hill of earlier 

 origin than the Wianamatta Shales, as he says that the latter have 

 been formed * partly from the waste material derived from the 

 former, and if this old diorite (?) hill be earlier than the Wiana- 

 matta it may also be earlier than the Bulli Coal-measures which 

 may consequently mantle round its base, and some of the foi'ma- 

 tions intermediate between the Wianamatta Shales, and the Coal- 

 measures may almost entirely thin out as they approach the old 

 inlier. The solution of this question will obviously have a very 

 important bearing on the future of coal mining in the neigh- 

 bourhood of Prospect near Parramatta. Against this evidence of 

 the possibility of the Newington cupriferous shale being syn- 

 chronous with that of Holt-Sutherland, must be adduced the fact 

 that layers of tuffaceous shale, certainly in part of volcanic 

 origin, have lately been observed by me in the core from the 

 diamond drill bore at Moorbank, near Liverpool. These layers 

 were intercalated with the lower beds of the Hawkesbury Sand- 

 stone just above the chocolate shales of the Narrabeen beds. 



* Remarks on the Sedimentaiy Formations of N.S. Wales, 4th Edit., p. 73. 



