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Art. XLIX. — On the Disposition of Alluvial Deposits on the Otago Gold Fields. 



By L. O. Beal. 



[Read before the Otago Institute, April 12, 1870.] 



The remarks 1 am about to make I crave indulgence for, as I can lay no 

 claim to scientific attainments, and my experience of the appearance and 

 physical constriiction of the country has only been gathered dui'ing some four 

 hurried business journeys of about ten days each, being in fact little more than 

 could be gathered by an ordinary coach traveller from Dunedin to Queenstown 

 and Skippers, a distance of about 200 miles. 



The question I am about to discuss, embraces the terrace formation of our 

 inland plains or basins, such as are observable in those of the Maniototo, 

 Dunstan, Cromwell, and Queenstown ; also, the question of deposits of gold 

 in old river beds, which we commonly term deep leads. The fii'st of these 

 basins — the Maniototo — is reached by proceeding up the Shag Yalley, over a 

 saddle in the spurs of the Kakaunui mountains, via Pigroot. I do not allude 

 to the terrace foi'mations in the Shag Valley, except to state my belief that 

 they have the same nature as the rest. The line of elevation also at which 

 the coaches travel up this valley is not favourable for noting these features. 

 In descending the saddle from Pigi'oot into the Maniototo Plains, our view 

 embraces the Rock and Pillar Range, lying slightly to the left ; the Kakaunuis, 

 over which we pass, extend to the right, till they reach the Mount Ida Range, 

 succeeded by the Little Ida, Hawkdun, St. Bathans, and Dunstan Ranges, 

 which are at abovit right angles, and extend along our route up country, and 

 form an arch or bow-like right hand boundary as far as the Dunstan township. 

 From the Rock and Pillar, on the left, at some distance a-head, the Rough 

 Ridge shoots out across our path, and may be said to join the right hand ranges 

 at the Little Ida, and thus form the Maniototo Plains. Passing over the 

 Rough Ridge, at a low elevation, our road crosses the Ida Valley, the extreme 

 left of which is under the Pinelheugh Range, Raggedy and Blackstone Hill 

 Ranges, crossing our road from the left in the same manner as the Rough 

 Ridge, and joining the right hand range at about the junction of the Hawk- 

 dun and St. Bathans Ranges. 



Passing out through Blackstone Hill we enter the Manuherikia Valley, 

 the left hand boundary being the Blackstone Hill and Raggedy Ranges as far 

 as the township of Manuherikia. At this point we meet the Molyneux River, 

 which here flows across the valley for about seven miles from the Dunstan 

 township, where it enters through a gorge, about thii-teen miles long, which it 

 traverses from the Cromwell Basin. The Manu.herikia Valley (across the 

 liver) is bounded by the Carrick and Old Man Ranges, and a few spurs of no 

 considerable elevation, in which are Conrov's and Butcher's Gullies. 



