368 Transactions. — Geology. 



Dr. Hector, in the "Geological Keports " for 1870-71, de- 

 scribing the geology of the Hawke's Bay District, makes use of 

 the term "Hawke's Bay series" for the same rocks as those 

 described by Hochstetter, and quotes from Hochstetter to show 

 that the beds belong to the " latest tertiary formation." Dr. 

 Hector traced the beds north and north-west from Petane to 

 Pohui, and as outliers, further north, beyond the Mohaka Paver. 

 He referred the Te Aute limestone to the Hawke's Bay series. 

 This bad been done by Captain Hutton on the 12th September, 

 1870. 



Thus, to the middle of 1871, there appears to have been no 

 question as to the " late tertiary age " of the Hawke's Bay 

 series, nor as to the conformable relations of all the beds 

 ascribed to it. Next year (5th November, 1872) was published 

 Captain Hutton's " Synopsis of the Younger Formations of New 

 Zealand." and of this, the " Hawke's Bay group " was referred 

 to the oligocene period. This Hawke's Bay group is typically 

 represented by the same locality as that of the " Hawke's Bay 

 series" of Hochstetter, viz., "Napier," but other and distant 

 localities are added, and rock formations of a class and age 

 never contemplated by Hochstetter. The result of this inclusion 

 of strata older than the Awatere series of Hochstetter, was to 

 lower the percentage of recent species found fossil in the beds to 

 20 per cent. ; and, as a consequence, the reference of the Hawke's 

 Bay group to a much earlier period than the Hawke's Bay series 

 had been referred to. How far the two should be considered 

 identical may be inferred, and remains to be seen. 



In 1873, Captain Hutton suppressed the name " Hawke's Bay 

 group," and substituted " Ahuriri formation " in its place, and, 

 describing its fossils, considered that 23 per cent, of its mollusca 

 and echinodermata were recent species. The Hawke's Bay group 

 or Ahuriri formation was now referred to the lower miocene 

 period. 



In June, 1875, the same beds were, by Captain Hutton, 

 referred to the middle miocene period. 



On the 4th of January, 1875, I divided the tertiary strata of 

 Hawke's Bay District into Lower or Hawke's Bay series, and 

 Upper or Wanganui series, including the shelly limestones of 

 Napier with the lower group or series. During the early part of 

 1876, Mr. Cox examined the country between Poverty Bay and 

 Napier, and determined the tertiary rocks of the district as a 

 single sequence, to winch, however, he assigned no particular 

 period, eocene or pliocene. He considered the Napier limestone 

 to be near the base of the series, although his statements are 

 somewhat incompatible with the assumed conformity of the 

 whole series of tertiary beds described by him. Dr. Hector at 

 the time considered the higher beds described by Mr. Cox as 

 belonging to the same horizon as the Upper Wanganui beds. 



