310 Transactions. — Geologij. 



the beds above the Parnell grit at Parnell as " yellowish sands and sandy 

 clays easily distinguished from the beds underlying the grit bed," and from 

 this he concludes that "there is a marked distinction in the character of 

 the beds overlying and underlying the Parnell grit."* This statement I 

 may be allowed to question. In 1866 I examined these rocks at the typical 

 locality at Parnell and found that at the east point of St. George's Bay the 

 volcanic ash, called by Dr. Hector the Parnell grit — here about 15 feet 

 thick — is overlaid by a bed of yellow sandstone above which comes a set of 

 false bedded sandstones and shales. It is underlaid by another set of 

 yellow sandstones and shales, also false bedded, below which is a greenish 

 sandstone going down to low water-mark. At Eesolution Point the Parnell 

 grit, greatly reduced in thickness, rests on a thin bed of clay, below which 

 is a thick stratum of yellow sandstone ; the ash of the Parnell grit 

 is much mixed with the clay, and the two beds are certainly quite con- 

 formable. Above the Parnell grit comes a set of thin-bedded sandstones 

 and clays, and on the west side of Hobson's Bay these are seen to be covered 

 by a thick stratum of clay. Thus in a distance of 600 yards the series, 

 both above and below the Parnell grit, has altogether changed its appear- 

 ance. The rocks at Point Britomart do not contain any beds of marl, as 

 stated by Mr. McKay, and they do not correspond exactly with the rocks 

 either above or below the Parnell grit at Parnell, but are more like the 

 beds above the Parnell grit in Hobson's Bay. This, however, is a matter 

 of little importance, for all the rocks of the Waitemata series are so local 

 that lithological evidence cannot be trusted for correlating beds a few 

 hundred yards apart, and I do not understand how Mr. McKay can, in 

 the absence of fossils, "easily identify" the rocks north of Lake Takapuna 

 with those underlying the Parnell grit at Parnell, which are five miles off. 



Again, Mr. McKay gives no stratigraphical evidence in favour of the 

 Orakei Bay beds being older than the Parnell grit. He commences by as- 

 suming, without giving any reason, that the beds at Point Britomart are 

 the Orakei Bay beds, and then says that at St. George's Bay they pass 

 under the Parnell grit. Both these statements may, however, be ques- 

 tioned. I will take the second first. On the east side of St. George's Bay 



* I.e., p. 106. Mr. McKay also says that " this is made perfectly clear by Mr. Cox in 

 his report already cited." Mr. Cox, however, says that the beds both above and below 

 the Parnell grit are sandstones and sandy marls " which occur throughout the series,' 

 but the grit represents the commencement of the volcanic outburst which attained its 

 greatest development near the Manukau Heads, the higher beds being notable for the 

 great abundance of the volcanic material which is mixed with the sand and clay. So 

 that, in the absence of volcanic ash, the upper and lower beds, according to Mr. Cox, 

 cannot be distinguished. On page 27 of the same report Mr. Cox also says that the beds 

 above the Parnell grit at St. George's Bay have " a similar but more indurated character" 

 to the strata of Fort Britomart. 



