450 



Transactions . — Geology . 



Racecourse Hill is oblong in form and rises about 50 feet above the plain. 

 Little Racecourse Hill is long, narrow, and rather curved, the concavity 

 facing the east end of the Malvern Hills. Its height above the plain is 

 about 30 or 40 feet. Gravel deposits are also found in places round the 

 base of the Malvern Hills, at estimated altitudes of from 50-70 feet above 

 the present level of the plains.* Ice-borne erratics are found in the upper 

 portions of the triangle and extend down as far as the ford just below the 

 junction of the Kowhai and the Waimakariri. These erratics are embedded 

 in river shingle. Dr. von Haast also mentions large morainic accumula- 

 tions on the western slopes of Abner's Head, a part of the Malvern Hills. f 

 In addition to these shingle hills, three others, formed of rocks of far more 

 ancient date than the gravels, rise through the plains. They are View 

 Hill, Gorge Hills and Burnt Hills. 



The Waimakariri River, rising in the heart of the New Zealand Alps, 

 breaks abruptly into the middle of the north side of this triangle through a 

 deep rocky gorge, called the Upper Gorge, at the eastern base of Mount 

 Torlesse, and runs with a southerly course for about two miles, until it is 



joined by the Kowhai 

 coming in art easterly 

 direction from the 

 apex of the triangle. 

 The Waimakairi 

 then flows in a 

 south-easterly direc- 

 tion for about 4^ 

 miles to Gorge Hill, 

 which it cuts into 

 two portions — Gorge 

 Hill on the south- 

 west and Little 

 Gorge Hill on the 

 north-east — forming 

 what is called the 

 Lower Gorge. This 

 is crossed by the 

 bridge for the Ox- 

 ford and Sheffield 

 railway now in 

 course of construc- 

 tion. 



* See Geological Reports for 1873-74, p. 57. 

 t Geology of Canterbury and Westland, p. 392. 



w.s.w 



WZZA JSlate -s- 



[: -"-v-"-l Grave Is 



