156 Transactions. 



the greensands helow tlie limestone in that locality with the Hutchinsonian- 

 Awamoan horizon at Oamaru, instead of correlating the fossiliferous beds 

 above the limestone at Wharekuri with that- horizon, as McKay had done 

 (1882b, p. 103). A similar error was made by Hutton in correlating the 

 greensands below the limestone at Waihoa with the Pareora (Awamoan) 

 horizon. Park's correlation lent support to his view that the Ototara 

 limestone and the Waitaki Valley limestone were at different horizons. 

 The latter in g, later work (1918, p. 110) still maintained that the Wharekuri 

 greensands are Hutchinsonian in age, but the writer is in agreement with 

 Marshall (1915, p. 386) that the greensands are pre-Ototaran. 



The geological evidence clearly shows that the Waitaki Valley is a 

 tectonic depression of post-Awamoan age, as affirmed by Cotton on geo- 

 morphological evidence, in opposition to the view of Park (1905, p. 523) 

 that the depression was in existence before the deposition of the Tertiary 

 sediments. 



II. General Description op the Area. 



From the vicinity of the Wharekuri-Otekaike fault, which bounds the 

 present area on the south-west to within half a mile of the Waitaki River, 

 prominent ridges and hills, possibly composed almost entirely of heavy 

 gravels and silts, form prominent features of the landscape between the 

 lower middle course of the Awahokomo Creek and the Kurow River. These 

 gravel uplands are in many places 800 ft. above the Waitaki valley-plain. 

 From the Kurow River to the Otiake River a gravel-covered tableland 

 sloping gently towards the Waitaki River forms a rather strong contrast 

 to the pyramidal hills and ridges just mentioned. Several prominent salients 

 stand above the general surface of this evenly sloping plain, and, where 

 their flanks have been cut into, fossiliferous beds are exposed. 



The south-western portion of the area is bounded by the steeply rising 

 foothills of the Kurow Mountains. Within a short distance of the fault- 

 line the country rises rapidly to a height of 3,000 ft., or over 2,000 ft. 

 above the valley-plain of the Waitaki River. To the north-east the area 

 is flanked by the block mountains of South Canterbury, reaching to heights 

 of 3,000 ft. not far from the Waitaki River, which now flows close to the 

 almost undissected front of these mountains. 



The average height of the Waitaki valley-plain is 650 ft. above sea-level. 

 Kurow Hill (1,947 ft.), composed of Maitai sediments (greywacke), rises 

 abruptly from the general level of the plain, and farther to the north-west 

 the hill on which Trig. Station G is situated reaches a height of nearly 

 1,300 ft., these two prominences being separated by the depression known 

 as the Little Awakino Valley. 



The district is thus a relatively depressed area lying between the block 

 mountains of North Otago and South Canterbury, drained by the Waitaki 

 River, which is fed, from the Otago side, by a number of small streams 

 flowing in a north-easterly direction from the Kurow Mountains. 



III. Geology of the Area. 

 (1.) Wharekuri Basin. 



On both banks of the Waitaki River, a mile below the point where 

 the Wharekuri Creek joins the main stream, there is an exposure of 

 glauconitic greensands extending for two miles down the river. A list 

 of fossils collected on the Canterbury side of the river has been published 



