Thomson. — Glacial Action in Otago. 323 



most striking are those of the Upper Chitha, near Cromwell ; of the Manu- 

 herikia, near Alexandra ; and of the Mataura ; but they are found everywhere 

 — from near the mountain tops to the sea shore — having the greatest dimen- 

 sions to the most diminutive. Those of the Upper Clutlia — a type of the 

 former — i-ise 200 to 300 feet, looking in the distance like a huge wall, and 

 attracting the astonished gaze of the beholder. 



These terraces are found to consist of shingle and gravel, bound more or 

 less loosely by clay and sand, i.e., where the prior, or tertiary, deposits are not 

 yet preserved from abrasion and transport ; and this principle universally 

 prevails — that the shingle becomes larger as you approach the mountains, and 

 smaller as you near the sea. Thus there has been a law of deposit : the 

 particles becoming smaller as the transporting power became weaker. Furthei', 

 there has also been a law of deposition and formation, for the terraces incline 

 as you close in with the mountains, and they tend to be level as you leave 

 them, and only becoming perfectly level on the sea or lake shores. And here 

 I may remark that in this part of New Zealand I have missed detecting any 

 raised beaches, so frequently spoken of by Eu.ropean geologists, excepting on 

 Lake Wakatipu, where those that exist there have been formed by the unusual 

 circumstance of the lake once having an outlet by a diiferent direction than 

 the present one, and at a higher level, viz., by the valley of the Mataura. 



In illustration of the varying inclination of terraces, I beg to adduce the 



following facts from actual survey. Commencing from the sea shore at the 



Waitaki plain, and following up the lower terrace parallel to the river, we 



found — 



From z to x, Papakaio, in distance 14,400 feet, the rise is 52 feet, or 3 "6 per 1,000. 



X to V, „ „ 10,600 „ „ 40 „ 3-8 



vto Q, „ „ 13,400 „ „ 59 „ 4-4 



Qto R, „ „ 12,700 „ „ 22 „ 1-7 



R to s, Awamoko ,, 14,300 ,, ,, 25 ,, 1*7 ,, 



s to G, „ ,, 10,300 „ „ 29 „ 2-8 



Gtox, „ „ 25,600 „ „ 77 „ 3-0 



It is so evident that the cases are similar with the terraces of the Molyneux, 



Taieri, Mataura, and other large rivers, near their mouths, that to detail them 



would be tedious and of no use ; we therefore go at once to the interior. On 



the Manuherikia the following are the inclinations of the terrace that abuts 



near Alexandra : — 



From w to k, Liang Rock, in distance 12,300 feet, the rise is 84 feet, or 6 '8 jDer 1,000. 

 „ K toH, „ „ 9,100 „ „ 99 „ 10-8 „ 



„ H toE, „ „ 13,200 „ „ 234 „ 17-7 



„ E to c, „ „ 16,000 ,, „ 1,250 „ 78-0 



At the Upper Clutha, with one terrace abutting near Cromwell — 



From H to i, Cromwell, in distance 16,400 feet, the rise is 728 feet, or 44 '3 per 1,000. 



And, with another terrace abutting near Wakefield — 



From J to K, Cromwell, in distance 12,400 feet, the rise is 731 feet, or 59 '0 per 1,000. 

 Thus, there is a law indicated in the nature and formation of these terraces, 



