Dobsox. — On the Date of the Glacial Period. 445 



This is not unreasonable, for without proof I see no reason why we should 



imagine elevation or subsidence to occur horizontally over any large area; 



movement confined chiefly to the west side of the island would account for 



several apparently irreconcilable difficulties. It must be understood that 



I mean movement greatest near the west coast, and lessening eastward, 



becoming nothing at the east coast; it would fully account for raised beaches 



on the west coast, and none on the east. As there is some doubt as to 



whether the auriferous leads on the coast are raised beaches, a short description 



will not be out of place here. From Hokitika on the south to Karamea on 



the north, drift deposits occur, which are all more or less auriferous. These 



deposits are composed of gravel and sand; the gravel being granite, indurated 



sandstone, quartz, and hard schistose rocks, all well water-worn, and having 



the circular disk-like form always met with in beach shingle. 



Confining description to the Nelson Province, a lead of this description 



occurs at Point Elizabeth, four miles north of the river Grey ; it is about fifty 



feet above the present sea level, and was most probably deposited by the 



combined action of the sea and river on what was then a beach at the mouth 



of the Grey, the river Grey having once had its outlet to the northward of 



Point Elizabeth, before it broke through the limestone range and formed its 



present channel. The drift either lodged only in this spot, or, if there was a 



greater extension, all trace has been washed away, for the deposit which 



proved so very rich in the early days of the Grey diggings extended for a 



distance not exceeding thirty chains in length, nearly parallel to the existing 



beach, and not more than one or two chains in width. 



Proceeding northwards, patches of gravel occur at a height of about sixty 



feet above sea level at various places along the hill sides, but none have 



yielded much gold, until we arrive at Brighton, where the drift extends over 



a considerable area of country. The gold leads in this district exactly 



resemble beaches, and are parallel to the present water line. 



From Brighton northward to the Waimangaroa the drift extends, bearing 



numerous gold leads, the highest being at Dawson's Terrace, about 400 feet 

 above the present sea level. Near Charleston leads were worked on six 

 different levels, all of which bore the same littoral character. North of 

 the Buller the leads rest on a bottom of fine sandstone, are overlaid by a drift 

 of heavy granite boulders, which is in its turn capped by a mass of large 

 sandstone blocks, which I believe have been brought down from Mount 



Rochfort by glacial action. 



It is impossible to give an adequate description of these gold leads in a few 



words, or to convey any useful information unless accompanied by plan and 



be 



and 



origin. 



