410 Tran&actions. — Geologj/. 



land being deeply intersected by numerous tidal rivers and 

 ramifying arms of the sea. 



The evidence of the Kawakawa boreholes, supplied by 

 Mr. McKay, seemed perfectly conclusive that the hydraulic 

 limestone was superior to the coal-measures ; but I found, on 

 making inquiries from Mr. T. P. Moody, under whose super- 

 vision the boreholes were put down, that no hydraulic lime- 

 stone was actually cut in the boreholes. The beds in No. 2 

 borehole, referred by Mr. McKay to the Amuri-limestone: 

 group of the Cretaceo-tertiary, were as follows : — 



Ft. in. 

 Blue clay .. ... ... ... 30 



Chocolate-coloured clay ... 10 



Soft clays, no core ... ... ... 194 2 



234 2 



It is obvious from the above that Mr. McKay did not base- 

 bis opinion regarding the superior position of the hydraulic 

 limestone upon the identification of that rock in the material 

 cut in the borehole, but correlated the above clays with the 

 Amuri limestone, apparently because these clays occupied 

 the position relatively to the Whangarei limestone which 

 the hydraulic limestone was supposed to occupy.* 



After an exhaustive inquiry in 1899 as to the position of 

 the hydraulic limestone, I found (a) that the hydraulic lime- 

 stone is conformable to the glauconitic greensands and cone- 

 in-cone beds at Batley and elsewhere, and belongs to the same 

 sti-atigraphical system ; {h) that the Geological Survey was 

 right m correlating the hydraulic limestone with the Amuri 

 limestone, but (c) was wrong in placing the hydraulic lime- 

 stone above the Whangarei limestone ; {d) that I was right in 

 correlating the Whangarei limestone with the Oamaru stone; 

 (e) that I was right in placing the liydraulic limestone below 

 the Whangarei limestone, (/) but wrong in identifying the 

 white clays interstratified with shelly limestone in the Pahi 

 section with the hydraulic limestone ; (g) that the green- 

 sands at Pahi containing a Tertiary fauna occur at the base 

 of the Lower Tertiary series, and are probably the equivalent 

 of the greensands forming the roof of the coal at Kawakawa 

 and Hikurangi ; and {h) that the Komiti beds, referred by 

 me doubtfully to the Pareora series, probably form the lowest 

 horizon of the Lower Tertiary series— or, in other words, that 

 the Komiti beds form the lower beds of the Pahi greensaud 

 series. 



The stratigraphical connection of the hydraulic limestone 

 to the Inocerainus greensands was practically admitted by 



• Eeps. Geol. Expl., 1883-84, p. 133. 



