SAND DUNES

Evening Post, Volume XC, Issue 83, 6 October 1915, Page 2

SAND DUNES

The .importance of the sand dune question was emphasised by Dr. L. Cock ayne, F.R.S., in the course of a lecture before the Wellington Field Naturalists' * Club. The title of the address wat " Sand Dunes, Their Origin, Flora, aad Control." The lecturer traced the man ncr in which sand was ■ formed bi V disintegration of the rocks, and how .- was washed down by the rain into the rivers and thence to the sea. From t'"J sea it was brought back by currert- . etc., and cast on to the sea short X points where a suitable^ landing vis afforded. In this way beaches of saiwl were formed. The sand on these beaches became -dry and -was •driven, back fcjr winds, forming sand dunes according to the character and formation of the land on to which that sand was blown. The importance of the sand dune question, he went on to say. should be broughi home to us when 'we consider^ that in New- Zealand alone over 300,000 acres which were once fertile fields or native forest were now completely covered by sand/ Even churches, % homesteads, etc., had been completely buried by the encroaching of sand dunes. The formation of sand dunes he dealt with very explicitly and fully. He said they were constructed on an exact parallel to the formation of the ripples which were to be seen on any sand area. The vegetation of the sand dunes he dealt with at some considerable length, and showed how it was possible finally to clothe the sand ■with so dense a growth of_ plants that further movement of that Band was impossible. Let that growth be destroyed, however, even if in only a small limited area, and very soon the whole dune would again become s&bare moving dune, killing all growth before it. The first field excursion of the dub took place on Saturday afternoon, when the members visited Lyall Bay, and discussed and examined the sand dunes. The theories advanced by Dr. Cockayne were verified on practical investigation, and the afternoon proved a most enjoyable and instructive one.