436 PROCEEDINGS OF SECTION B. 



metamox'phic rocks. In Bone of these sections can any line of demar- 

 cation be found between the two series, and the gradual change from 

 one type to the other is not complete before from 3 to 5 miles of 

 country have been traversed. It is, therefore, reasonable to refer the 

 schists to the group of sedimentary rocks into which they gi-aduate. 

 In the first three instances given the sedimentaries contain fossils 

 that are certainly of Triassic age, and are probably of the same age 

 in the other localities. Apart from this it is at any rate certain that 

 Triassic and Jurassic rocks, distinguished by distinct fossils, are 

 deeply involved in the folds in the southern portion of the affected 

 rock mass. 



Another of the old fold lines of Gregoiy is in the north of the 

 Auckland province. Here the folding action has almost completely 

 obscured the stratification planes to such an extent, in fact, that both 

 Darwin and Dana failed to detect a line of folding in the Bay of 

 Islands. Suess remarks of this area, that Palaeozoic rocks are " only 

 the isolated fragments of the sunken range," and " the north-western 

 coast, therefore, in no way represents the actual trend of the moun- 

 tains." 



However, Mr. E. Clarke has recently made a close examination 

 of these rocks at Whangaroa, and Dr. Bell and he have extended 

 their observations to the North Cape. During their work they have 

 recognised a north-north-west line of folding, a conclusion opposed to 

 that of the writer, gained, however, from less extensive work in 1906. 

 Although this recent work establishes the north-north-west direction 

 for the line of strike, there is no reason to suppose that it is an older 

 line of fold than that of the main mountain line of the North Island. 

 In fact, McKay found Triassic rocks at Spirits Bay, and Clarke thinks 

 Triassic the extreme limit of geological time to which these rocks can 

 be referred. No other observer, therefore, supports Gregoiy's opinion 

 that an old N.W.-S.E. fold line exists in the extreme north. 



It is well known that in New Zealand the main structural axis 

 bends round in the south from south-west to south-east. There is, 

 however, a large mass of ancient rocks further to the west — perhaps 

 of Archaean age. In these Hutton distinguishes a N.W. dip that is a 

 N.E. strike in 1875, and his conclusions have not been disputed. No 

 important sections between these N.E. striking rocks and those with 

 a N.W. strike has yet been described, though one occurs on the north- 

 east side of Lake Te Anau. In this section there appears to the 

 writer to be a great unconfomaity, but it has so far proved impossible 

 to make a close inspection of it. In the north-west of Nelson minute 

 and accurate work has been done by the Geological Survey on the 

 Ordivician and other ancient rocks. A N.N.W. and S'.S.E. strike was 

 found there. 



It is often taken for granted that the main fold line of New 

 Zealand from the east of Poverty Bay to Cape Terawhiti and Culver- 

 den is of Carboniferous age. (Mawson, L. S., N.S.W., 1905, p. 474.) 

 It cannot, however, be too clearly stated that, as recognised by Hutton 

 in 1885, the main rock folds were formed in the late Jurassic. That 

 this is the case is shown at Waikato Heads, Kawhia, Nelson, Hokanui 

 Hills, and Coromandel Peninsula, in all of which places Jurassic rocks 

 are involved in the folds, while in no known section is there any 



