416 Transactions. — Geology. 



extension of the Takapuna ash-beds. He says, "Immediately 

 north of the lake, where the sea-cliffs are higher and the rocks 

 better exposed, they are easily identified as those underlying 

 the Parnell grit. . . . Nearly two miles bevond the 

 lake grey sandy marls referred to the lower beds are overlaid 

 by a volcanic agglomerate which corresponds to the Parnell 

 grit, differing only in the coarser material which composes it, 

 blocks of volcanic rock more than a foot in diameter being 

 common." 



In the following year, 1884, Professor Hutton read a paper 

 before the Philosophical Institute of Canterbury on the age 

 of the Orakei Bay beds, in which he reviewed most of the 

 literature bearing on the Waitemata series. He contended — 

 (1) That there is no evidence to show that the Orakei Bav 

 beds are older than the Parnell grit ; (2) that on the whole 

 the evidence, both stratigraphical and palaeontological, is in 

 favour of Orakei Bay beds belonging to Pareora svstem 

 (Lower Miocene). 



Sir James Hector, in his progress report for 1885, briefly 

 referred to the interstratified volcanic grits in the Waitemata 

 series. He dissented from Mr. McKay's view that the Parnell 

 grit is the southern extension of the Takapuna ash-beds. 



In 1885 Mr. James Park, F.G.S., in a report on "The 

 North Shore to Lake Takapuna," wrote, " In the cliffs at the 

 end of Cheltenham Beach occurs the volcanic breccia or grit 

 seen on the coast north of Takapuna. Here it is almost 

 identical with the Parnell grits. At Judge's Bay the strike is 

 north-north-east, which would carry them under the tuffs at 

 the North Head to the place indicated at Cheltenham Beach. 

 These sandstones, although much disturbed in places, nave a 

 general dip to the west, and at the first point north of the 

 lake are lying on a volcanic ash-bed or breccia bed containing 

 many large angular fragments of scoriae and lava, which 

 appear so recent in character that when broken off it would 

 be impossible to distinguish them from the basalts of Mount 

 Eden." 



Section III. — Sketch of Geology of District. 



The rocks comprising the cliffs and shores of the Auckland 

 Harbour fall readily under four heads, and serve to indicate 

 as many distinct periods of geological time. 



The oldest rocks of the district are the Palaeozoic or 

 Maitai slates (presumably of Carboniferous age), a compact 

 indurated sandstone which covers considerable areas in 

 Waiheke, Motutapu. and several other islands in the Hauraki 

 Gulf, and is continued into the Wairoa Ranges. 



Following these slates, lying, indeed, unconformably on 

 them in places (as at Motutapu), are the Waitemata beds, of 



