62 Transactions. 



gravel, above which comes 15 ft. of pebbly sand and 4 ft. or 5 ft. of loamy 

 subsoil and soil. The seepage from these beds supplies a water-trough. 

 On a branch road up a small valley south of the railway-station Waitotaran 

 claystone is seen to be overlain by 30 ft. or 40 ft. of sand, mostly dark- 

 coloured, the lower layers of which contain many pebbles of greywacke 

 and numerous fragments of claystone. Another water-trough indicates a 

 permanent water-seepage from the base of these beds. 



Thomson (7, p. 416) explains the Hawera beds as having been deposited 

 upon a wave-eroded surface of the Wanganuian beds during an advance 

 of the sea. The writer's observations, though entirely supporting most of 

 Thomson's statements, lead rather to the conclusion that the Hawera beds 

 were formed wholly or mainly at a somewhat later stage — namely, during 

 the subsequent retreat of the sea, caused by land-elevation. 



As has been shown by Thomson, the Hawera series is unconformable 

 to the Wanganuian formation. Since the Upper Wanganuian or Castle- 

 cliffian is of Upper Pliocene age, the Hawera series falls into the Pleistocene. 

 No shells were seen in it at Patea, but at Hawera Thomson collected a 

 large number of Recent species from a shell-bed at the base of the series. 



The Hawera beds, as pointed out by Thomson, give rise to a rich soil 

 of great importance to the agriculturist. 



Post-Hawera Dejoosits. 



In the small valley south of the Patea town bridge there is a low hill 

 formed of fine gravel and sand, similar in appearance to the gravel and 

 sand of the Hawera series. Since this hill is far below the general level 

 of the Hawera series, one must suppose that the material of which it is 

 composed represents a rewash of the Hawera series. 



The ferriferous sand-dunes capping the cliffs have already been men- 

 tioned several times. The material of which they are formed has probably 

 been partly derived from the Hawera beds (as suggested by Thomson), and 



Sandhills __ 



r ).'l'^'.V' ft;. , .t:'.. Jiawerco 

 •-•A'-'„Vooo.o.»" Series 



Toutecu 

 clccvs 



Section West of Mouth of Patea River. 



partly from an ancient belt of dunes formed on the old coast-line immediately 

 after the last elevation of the land had ceased. The prevailing wind is 

 probably from the south-west,* and hence as the sea attacked the land, 

 and cliffing advanced, the bulk of the ancient dune-sand was blown inland. 

 Wind-action is strong at the cliff-edge, and keeps it clear of loose sand. 

 Although some sand falls or is blown over the cliff, this loss is more than 

 counterbalanced by sand derived from the Hawera series. R. Pharazyn, 

 in 1870 (1. pp. 158-60), explained the present dune-sands on top of the 

 cliffs along the shore of the Wanganui Bight as the remnant of a wide belt 

 formed before cliffing began, but the idea that the sand was blown inland 

 as the cliffs advanced was not clearly expressed in his paper. 



* In summer there is a frequent sea breeze. 



