The Southland Times SATURDAY, JUNE 25, 1938. Oil Prospects In Southland

Southland Times, Issue 23544, 25 June 1938, Page 6

The Southland Times SATURDAY, JUNE 25, 1938. Oil Prospects In Southland

In an article in our news columns today a correspondent calls attention to the possible existence of an oil field in Southland and suggests that the present is an opportune time for investigation. The possibility of commercial oil discovery in Southland has been keenly discussed for many years past. At one stage a small company was formed with the object of testing the possibilities of a “strike” in the Winton-Dipton area. Two bores were sunk to a considerable depth but, as far as we are aware, the results were negative. Seventeen years ago Professor Park made a geological survey of western Southland to investigate the probable extension of the Nightcaps and Ohai coal measures, as well as the possible occurrence in the district of brick and pottery clays and limestones and marls suitable for the manufacture of Portland cement. He referred incidentally and in a few lines to the prospects of oil discovery in the Clifden-Tuata-pere area, and stated that “if an oil pool exists anywhere in western Southland it will be found in this area.” He did not investigate the locality in detail but considered that the geological structure and the nature of the strata justified boring. As far as we know, the usual indications that petroliferous strata lie beneath the surface —gas emanations, oil seepages and mineral springs—have not been proved to be present in that area. It is possible, of course, that even in the absence of these “indicators” the strata may be oil bearing, but much more detailed work will be necessary before boring is justified. Modern oil geology demands four essential conditions before boring is warranted: a source of oil (some of the beds must contain remains of organic matter); a porous bed, which serves as a reservoir in which the oil from the source may accumulate; an overlying impervious bed to prevent the escape of oil as it has been accumulating during past geological ages; and a suitable structure of the rocks (the beds must be arched upwards or 'anticlinal in structure). An oil expert would demand a full investigation of these factors before he could determine the site of a bore, and this is peculiarly the work of the Geological Survey in this country. In the North Island this indispensable preliminary work has been carried out in great detail by Government geologists and the stage is now set for the work of the visiting oil experts. In many parts of Southland and particularly in the Clifden-Tuatapere area the work has not been done in sufficient detail from the geological point of view to warrant the employment of these experts in Southland at the present time. There is, however, ample justification for the extension of the geological work that has already been done in Southland by the officers of the Survey. Part of western Southland has already been investigated in detail and the results are incorporated in Bulletin 23 of the Geological Survey Department. During 1936 and 1937 the geologists of the Surrey were engaged in detailed work in the Waikaia-Chatton area and their investigations should be extended to the rest of Southland. The main purpose of a geological survey of New Zealand, as of any other country, is the production of a detailed geological map of the country with accompanying reports on the nature of the rocks, their fossil contents and their geological age. Such a work will form a sure basis for the development of the rich natural resources of the country. Some of the activities of the geologist, such as the collection and identification of fossils, appear to the layman to have no economic value and to be quite irrelevant as far as the commercial aspects of mining and oil production are concerned. It cannot be too strongly emphasized that without this work geology could not exist as a science, and scientific prediction of the occurrence of oil and other sedimentary products of economic value could not be made. The oil. and mining industry, agriculture, engineering, the development of our water resources and the control of river erosion are some of the activities depending to a greater or less extent upon the preliminary detailed work of the geologist. As instances of the waste of natural resources and money which the geologist could have prevented, it is possible to quote two cases in Southland. At Waikaia nearly 1900 tons of high-grade shale oil were used as fuel and many thousand tons have been rendered unextractable. As the late Director of the New Zealand Geological Survey has said, “Mining of the Waikaia or similar shales for use as fuel alone ought to be prohibited. Any shale that will burn like coal is much more valuable for its gas, oil and paraffin contents.” The other instance is the one already referred to in the Winton-Dipton area. It was known to the geologist that this area was structurally unfavourable to the presence of an oil

reservoir, yet two bores were put down and the results were negative. Subsequently an officer of the Geological Survey visited the district and reported that the structure of the locality where boring had been carried out negatived the possibility of finding oil. Much disappointment would have been avoided and capital saved if the examination had been made before the boring was commenced. The exploitation of the oil, shale coal and other valuable resources of Southland can be carried out expeditiously and economically only after an extension of the investigations that the New Zealand Geological Survey has already made; and it is to be hoped that there will be some organized effort in the near future to impress on the Government the need for this extension.