Hill. — On tlie Geology of Hawke's Bay. 395 



which they sometimes dam back until a new channel has 

 been cut. 



At the stream known as Kereru, five miles or so from 

 Weber, the rocks belonging to the upper greensanJs appear. 

 These sands contain concretionary bands of impure limestone, 

 which are fossiliferous, but exposure to the weather rapidly 

 acts upon them, and they quickly decompose. The green- 

 sands are filled with black flakes resembling lamellar horn- 

 blende, but whether they are hornblende or not I cannot say. 

 These greensands seem to me to belong to the same series 

 which are so largely developed along the coast-hills between 

 Porangahau and Wainui — Cook's Tooth being the central height 

 — and are first met with on the top of the hills overlooking 

 Porangahau on the Wallingford side. In neither of the latter 

 places, however, have I observed a ferruginous limestone band, 

 but, as traces of this greenstone extend to the hills overlook- 

 ing the Roan Creek, a mile or so from the Weber Township, 

 there caii be but little doubt that they are the representative 

 beds of the coast greensands, seeing that the Waipawa chalk- 

 marls make their appearance in this creek. Between Roan 

 Creek and the Akiteo Stream, where it crosses the road, the 

 whole area is made up of chalk-marls. In some places these 

 marls have a conchoidal fracture, but near their junction with 

 the blue clay they weather into small cubical pieces, and the 

 whole exposed surface has what may be termed cleavage- 

 planes not unlike the splintery slates at the base of the Rua- 

 hine, except in the matter of hardness. The blue marls con- 

 tinue from the Akiteo Stream past Tea-tree Point, and thence 

 onward to the top of the hill leading to the Wainui Stream. 

 No fossils of any kind were observed in these blue marls. 



At the bottom of the hill leading to the Wainui Stream the 

 black and brown oil-shales are well exposed. They have been 

 used here for road purposes, as they are the hardest rocks in 

 the district. These shales have a very wide distribution along 

 the east coast of the Island. Their most northern locality is 

 at Port Awanui, a few miles to the south of East Cape. There 

 they are largely exposed in connection with the greensands 

 and the blue-clay marls. The next place where they appear 

 as surface-rocks is near the Waipaoa homestead, on the Wai- 

 paoa River, thirty-five miles to the north-west of Gisborne, in 

 the vicinity of the once much-talked-of Poverty Bay oil-springs. 

 They are next seen well exposed near Baker's Brewery, at 

 Waipawa, within half a mile of the town, and again on the top 

 of the hills overlooking Porangahau. In each place named 

 they are met with in connection with greensands and chalk- 

 marls. Southward from Porangahau no trace of the rocks is 

 again met with until reaching the Wainui Stream, when they 

 are exposed three times along the high banks in a distance of 



