316 



Transactions. 



Art. XXXVIII. — The Tuamarina Valley : A Note on the Quaternary 

 History of the Marlborough Sounds District. 



By C. A. Cotton, Victoria College, Wellington. 



[Read before the Wellington Philosophical Society, 23rd October, 1912.] 



Plates XV, XVI. 



Introduction. 



Immediately after leaving Picton the railway to Blenheim climbs a low 

 saddle, and afterwards follows a comparatively straight valley — that of the 

 Tuamarina — for its full length of ten miles, emerging on the Wairau Plain 

 at the junction of the Tuamarina River w.th the Wairau. 



Fig. 1. — LocAUTY Map, Central New Zealand. 



P, Picton ; B, Blenheim ; T, Tuamarina River ; Q, Queen Charlotte 

 Sound ; TC, Tory Channel ; PS, Pelorus Sound. 



The writer was able recently to make a few observations which may be 

 of some value, inasmuch as they throw light on points connected with the 

 physica' geography of this portion of Marlborough to which little attention 

 has hitherto been directed. 



Our previous knowledge of the physiography of the Marlborough Sounds 

 and adjoining country may be summed up as follows : — 



1. The Sounds are submerged river-systems.* 



2. Subsidence to the extent of 5 ft. in the neighbourhood of Blenheim 

 was noted at the time of the earthquake of 1855.t 



3. The line of the Wairau Valley has been recorded as an " active " 

 fault marked by earthquake-rents. { 



* Marshall, P., "The Geography of New Zealand" (Christchurch, no date), p. 68. 



t Lyell, C, " Principles of Geology," 10th ed., 1868, p. 87. 



I McKay, A., Rep. Geol. Expl., 1890-91 (Wellington, 1892), map, p. 1. 



