Wells. — On the Drift Beds of Wakapuaka. 347 



rolling about on their journey to where we find them. If these surmises 

 are correct, then some force must have been at work to bring them to their 

 present position. This force the observing geologist concludes has been 

 water, bringing down fragments from the parent rock, also detritus of a 

 lighter material in the form of clay, and depositing it at sea-level. How- 

 ever, we find this deposit, as I have before remarked, far above the level of 

 the sea, consequently some other force must have been at work to raise it to 

 the elevation at which it now stands. 



If we travel up the Maitai, a short distance before reaching the slate 

 formation we find a range of greenstone dykes running in a north and 

 south direction, and to them I presume may be attributed the upheaval of 

 this raised beach. "Where these dykes obtruded themselves, the elevation of 

 this boulder drift was the sequence. I may mention here that the boulders 

 in this drift are of a different mineralogical character from those brought 

 down by the Eiver Maitai, being mostly hard indurated sandstone and con- 

 glomerates, while the Maitai drift partakes more of rocks of a crystalline 

 character, such as serpentine, hypersthene, dunite, and various hornblendic 

 rocks, with a mixture of slate, so we must look for another outlet for this 

 Wakapuaka drift than the Maitai. If we examine the back country 

 north of the Maitai, and onwards towards the Happy Valley outlet, 

 we will find the same sandstones and conglomerates in situ and they are at 

 the present time being brought down by the Ludd Stream, which flows 

 through that district, so that we may fairly conclude that this drift has 

 been carried from the degraded rocks of the higher country behind, and 

 subsequently raised by the ejecting of the greenstone. 



The Port Hills are all drift matter, overlying the sandstone which is 

 exposed at the cliffs, part of which has been carried from the eastern ranges 

 and part from the west, and is very easily defined. The western drift is 

 well shown on the ridge at the back of Major Eichmond's property, contain- 

 ing granite boulders in the clay, and as no granite is found on this side, in 

 sitit, we may conclude that this drift material came from the west, granite 

 there being the prevailing rock ; and on examining the Port Hill faces on 

 the Nelson or township side, they partake more of the material which 

 might be expected to come from the Wakapuaka Eanges ; so that water- 

 force must have been at work both on the east and west side of these drift 

 beds. 



In mostly all sedimentary strata of any considerable antiquity we find 

 faults occurrhig, that is to say, we seldom find them in the same horizontal 

 position in which they were deposited, but either at a less or more abrupt 

 angle, having been subjected to internal forces from underneath. These 

 greenstone dykes I have been speaking of are one of a large family generally 



