Speight. — Physiographij of the Cass District. 145 



Art. XVII. — Notes from the Canterbury College Mountain Biological Station. 



No. 2. — The Physiography op the Cass District.* 



By E. Speight, M.Sc, F.G.S. 

 [Bead before the Philosophical Institute of Canterbury, 1st December, 1915.] 



Dr. Charles Chilton, who is in charge of the Cass Biological Station, 

 has asked me to furnish a short description of the most important physio- 

 graphical features of the locality, with a view to its use by students and 

 others who visit the station. I therefore trust that these notes may be of 

 some service, and that they may perhaps form a basis for reference in the 

 case of future biological work done in the locality. 



The station is situated at an elevation of 1,850 ft., in the vicinity of the 

 Cass River. This river rises in the Craigieburn Mountains, and follows a 

 tolerably straight course in a northerly direction, at first through a narrow 

 mountain-valley, afterwards through a gently inclined plain — the flood- 

 plain of the river — till it discharges through a short gorge into the Wai- 

 makariri River, just below the spot where that river receives from the north 

 the waters of the Hawdon (1,746 ft.). The Cass Valley is bounded on the 

 west by a forbidding rocky ridge running parallel to it, whose most important 

 summits are Mount Misery (5,768 ft.) and Mount Horrible. About a mile 

 from the termination of this ridge it is cut down, and forms a low saddle 

 over which passes the coach-road into the main Waimakariri Valley ; this 

 is now known as the Cass Saddle, though in the early days it was called 

 Goldney's Saddle (1,929 ft.). On the east side of the Cass the country 

 is open, but a well-defined line of low hills runs south towards Mount 

 St. Bernard (5,509 ft.), and divides the area into two distinct valleys. In the 

 westerly one lie Lakes Grasmere and Pearson, and in the eastern one lies 

 Lake Sarah. Lake Pearson is the largest of the three ; it is about two miles 

 and a half in length, and nearly half a mile wide at its widest part ; but it 

 is almost cut into two in the middle, partly by an old moraine, and partly by 

 huge shingle fans, which approach each other from opposite sides of the lake. 

 It is at an elevation of 2,085 ft. above the sea, and has never been known 

 to freeze over. It discharges by Winding Creek towards the Broken River. 

 Grasmere is a much smaller lake, about a mile in length, and nestling close 

 under the ridge which divides the two valleys. It discharges by the Gras- 

 mere Stream, which flows through swampy ground close past the station, 

 into the Cass River. Lake Sarah is a small shallow lake, 21 ft. in depth, 

 lying on the opposite side of the ridge from Lake Grasmere, and discharg- 

 ing into the Grasmere Stream. Immediately to the east of the station, 



* The places mentioned in this article are indicated in the accompanying locality 

 map. 



