Hill. — Geology of Hawke's Bay. 457 



tion is in a north-east and south-west direction, in what was 

 apparently an immense valley which communicated with the 

 sea on the east by several transverse valleys, which subse- 

 quently became the valleys through which the rivers from the 

 western watershed pursue their course to the ocean. 



The question next arises as to what occupied the area 

 previous to the deposition of the conglomerates. I have 

 already explained that generally where the shingle and con- 

 glomerates are absent limestone is present — limestone belong- 

 ing to the same geological period as the Napier limestone. 

 Where there are no clays in Napier the limestones are pre- 

 sent, but where the clays are well developed the limestones 

 are either absent, or their rounded surfaces and bouldery 

 appearance testify to great denudation. Now, this rule holds 

 good over the whole of the district, except that the shingle 

 and conglomerates occupy the place of the loessic clays. 

 Previous to the deposition of the conglomerates the whole of 

 the area between the east coast and the present volcanic belt 

 of which Tongariro is the centre was covered with young 

 Tertiary limestone belonging to the Pliocene period. This is 

 proved by the fact that on the top of the Euahine Mountains 

 outliers of this limestone are found opposite the Kereru, and 

 the range immediately to the east of the Kaweka Mountains 

 is also made up of limestone, whilst similar limestone is to be 

 seen farther to the west at a height of 4,500ft. above sea-level 

 on the south end of the Kaimanawa Mountains. 



Now, all the Pliocene deposits with which I am acquainted 

 in this district are of marine origin, and it must be evident 

 that great changes have taken place in the surface of the 

 country since these deposits were formed. Either there must 

 have been elevation to the extent of 4,000ft. or more, or there 

 has been a lowering of the ocean to this extent. In any case 

 the fact remains that to-day there is a difference in elevation 

 of similar deposits in this district of more than 4,000ft., and, 

 as they are all marine deposits, it may be supposed there has 

 been elevation to this extent since the close of the Pliocene 

 period. At the close of this period there were no mountains 

 like the Euahine and Kaweka Eanges, for the whole countrv to 

 the south and east of Euapehu appears to have been covered 

 with limestone, and for some time after the elevation of the 

 Pliocene beds had begun it would seem that the drainage from 

 the volcanic centre was mainly to the north, east, and south. 



At the present time the watershed of Hawke's Bay may 

 be said to be limited by the Euahine and Kaweka Eanges ; 

 but it is certain from the products such as are exposed for 

 300ft. or more at the Kidnappers that the watershed w T hen 

 these deposits took place was in the direction of the volcanic 

 centre. Even before the mountains began to take definite 



