§ Mr. Dalyellasked the Minister of Technology what research he is doing into the extent to which coral rock such as that at Aldabra is soluble in sea-water, the extent to which coral rock can be undermined by the sea, and the probable consequences of heavy air traffic on such champignon substrata, in relation to subsidence.
§ Dr. BrayThe Ministry of Defence are interested in the coral atoll of Aldabra, and they have been advised by the Ministry of Public Building and Works that it is not necessary to build an airfield on champignon substrata, but that such an airfield could be built, at a cost, on platin rock which exists at one end of the island.
63WThe Ministry of Transport, Tropical Section of the Road Research Laboratory, published a Review in which it is stated that coral is virtually insoluble in sea water. Also coral rock usually co-exists with coral gravels and sands which often become covered superficially with clays; it is therefore necessary to make a thorough sub-surface investigation when considering construction on coral islands. Rain water does dissolve coral but the calcium carbonate usually re-precipitates out of the solution, and fills up the interstices of the coral thus having the overall effect of solidifying the coral. Airfields have been built on coral islands successfully, e.g. Bikini Atoll and Christmas Island. No research into the use of coral for construction purposes is being done at this time by the Ministry of Transport.