442 Transactions. — Geology* 



going on. Mr. Travers agrees in the main with Captain Hutton, only 

 supposes the elevation to commence during the miocene period, and continue 

 into pliocene times, subsidence and fresh upheavals occurring during pleistocene; 

 whilst I have considered both the elevation and subsidence to have occurred 

 in postpliocene times, and that no general elevation has occurred since. 



Before the former of these theories (Hutton's) can be accepted as tenable, 

 it is necessary to show that the newer pliocene is partly contemporary with, 

 and partly subsequent to, the glacial period, and in this case, as the glaciers 

 disappeared during the pliocene period, it would be impossible to find any 

 pleistocene strata covered by morainic matter. Captain Hutton regards the 

 Moutere Hill drifts, which cover so large a portion of the north central portion 

 of the Nelson Province, as older than the glaciers, in which case they must 

 be either miocene or older pliocene, but could not possibly be of later origin. 

 If I am not mistaken, the Moutere Hills are composed of the same drift (i.e., 

 are of the same age) as the drift which covers all the lower country from the 

 shores of Blind Bay on the north to the Mikonui Hills on the south — it 

 varies in character, being generally composed of the same materials as the 

 nearest adjoining mountains — for the most part it lies nearly horizontal, but 

 in the Grey "Valley and to the southward appears to have been slightly 

 disturbed, dipping somewhat to the northward and eastward. The general 



is much about the same throughout — drift shingle alternating with 

 beds of sand, the shingle in places forming a tough conglomerate with the 

 stones more or less decomposed ; in others the shingle hard and loose, and 

 washed down the gullies by every rain. Dr. Haast thus describes a section 

 he obtained in the Grey Valley : 



" Near the junction of the Mawheraiti with the Grey, on the southern side 

 of the main river, I obtained another section. Here the banks are almost 

 vertical, exposing a section of nearly 120 feet. In the river itself we find a 

 large stratum of clay marl, in which are also many pieces of drift wood 

 converted into lignite. These beds, of a bluish colour, are nearly horizontal, 

 and at one place the stump of a tree, fifteen inches in diameter, broken off 

 above the root, stands apparently in situ, the roots still adhering strongly to 

 the clay marl, so as to lead to the impression that it grew upon the spot. These 

 beds, which rise nine feet above the level of the river, were probably deposited 

 in a shallow estuary ; they are divided at unequal intervals by horizontally 

 deposited layers of mica ; they change insensibly into loam, which is 

 succeeded by a large accumulation of sand, gravel, and loam, interstratified 

 with layers of boulders, partly angular and partly rounded, and resembling 

 very much the drift formation near Nelson."* 



structure 



* Report on a Topographical and Geological Exploration of the Western Districts of 

 the Nelson Province, N.Z., by Dr. Haast, p. 103. 



