486 Transactions. — Geology. 



These I shall not again refer to. The following is a list 

 of the outcrops : (1) Shelly Beach, (2) St. George's Bay, 

 (3) Judge's Bav, (4) Newmarket, (5) St. John's College, 

 (6) St. Helier's Bay, (7) Tamaki West Head, (8) Howick, 

 (9) Maungamaungaroa Bridge, (10) White Bluff, (11) Cape 

 Horn, (12) Little Muddy Creek, (13) Point England. 

 (14) Blockhouse Bay(?). 



At Shelly Beach the grit forms a synclinal. It has been 

 described by Mr. Park, and I have nothing to add except with 

 regard to the fault on the east of the section. I do not feel at 

 all sure that this fault dips easterly, but I could not see the 

 line of fault, owing to landslips and the fact that the bank is 

 not high at Shelly Beach Road. 



At Acheron Point, half a mile to the east, occurs the 

 Ponsonby tuff. To that bed the dip is regularly west, so that 

 there is at least 100 ft. of strata above the Ponsonby tuff at 

 Shelly Beach. Now, the stratigraphical relations of the 

 Ponsonby tuff are very puzzling, but it will be shown later 

 that it is probably a little above the Cheltenham breccia, and 

 therefore much below the Parnell grit. But here, if the 

 Parneli grit is above it, it must be at least 100 ft. above. I see 

 no objection to this, and am therefore inclined to think the 

 Parnell grit is above the horizontal strata which form the 

 Auckland hills, near the wharves, at Freeman's Bav. Hobson 

 Street, Port Britomart, and Mechanics Bay. Mr. Park 

 strengthened this supposition by finding a few fossils, also 

 found at Orakei Bay, in the Mechanics Bay bed. Both Pro- 

 fessor Hutton and Mr. Park, however, believe that the grit 

 overlies these beds. 



Round St. George's Bay the grit dips under the sea. On 

 the west of the following bay (Judge's Bay) the beds are 

 much contorted. A section is given by Hochstetter. On the 

 east of the bay the Parnell grit is beautifully exposed. This 

 is the best locality for seeing the gradual shading-otf of the 

 coarser grit into a blue compact sandstone. Blocks have 

 fallen from all parts of the bed, and every variety of texture 

 may be observed. There are numerous zeolite veins running 

 across the bed. 



The next point at which the grit occurs (omitting places 

 already described) is a reef not far from the Bean Rock 

 Lighthouse. At the lighthouse itself the rocks are scoria- 

 ceous Auckland basalt. This cannot, I think, be derived 

 from the North Shore puys or Rangitoto Island (a basalt 

 volcano), since there is a deep channel between in each 

 case, so that it probably marks the site of an ancient 

 puy, perhaps a submarine one ; but more likely its present 

 position is due to the submergence of the old Waitemata 

 River, which has led to the formation of the Waitemata 



