SEARCH FOR OIL

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

SEARCH FOR OIL

Plea For Investigation

In Southland

GOVERNMENT AID IN THE NORTH ISLAND By HENRY R. WILSON Search for oil is being undertaken with Government aid on both the east and west coasts of the North Island. It is intended to spend a large amount of money for that purpose. Over some years efforts by private concerns have been made in order to secure if possible adequate flows. New fields are now to be tried and older ones more deeply probed. Mineral oil is such an important production in these days that countries possessing it have a unique advantage over those without it. There has not so far been discovered in the Southern Hemisphere any considerable flow of natural oil. The finding of a good field this side of the equator and more especially within the British Empire would be a matter of great importance. Recognizing this, the British Government has urged that search for petroleum should be energetically carried out. For commercial uses we need it and import large amounts, annually, and for Empire defence it might prove a decisive factor. The question arises, should not part at least of the contemplated expenditure be spent in testing Southland, where expert geologists have asserted oil is likely to exist awaiting development? Let us examine the evidence relating to the matter. Oil has been reported as seeping from the earth in South Westland, and there is no gainsaying the fact that in Southland we have the correct geological formations indicating the likelihood of oil.

THE SOUTHLAND PLAIN The great plain of Southland lies between the • Key of the lakes on the _ north-west to Wendon on the east, that line forming roughly the northern boundary, and on the south side Foveaux Strait. The general trend of this area of roughly 1600 square miles is geologically termed a monocline, gently sloping to the south. In common with most parts of New Zealand at different ages, this area has been successively raised and lowered. Lake Wakatipu once discharged its waters over it, as well as much larger lakes including Te Anau and Manapouri. Old lacustrine deposits are clearly seen at Horseshoe Bend. Nearly all the higher country is fossiliferous, both vegetable and marine fossils being abundant and as the formation dips gently as a whole southward there must be large estuarine deposits of carbonaceous matter lying there. Noted geologists assert that great coal and lignite beds lie under the whole of that plain. The formation of oil rather than coal requires that an impervious strata should, lie as the roof of such decaying matter; and that strata does exist, conglomerate sheets lie both below and above Southland coal. In considering what is called a plain, let it be understood that that formation is not necessarily flat in inclination but may have been like the Hokonui system, an upthrust. The Limestone Buttes, Femhill to Forest Hill, and in the Waiau valley are instances of this and the Hokonui hills have been raised to nearly 3000 feet and at Mount Hamilton to over 4000 feet in this senes. The dip of Southland and South Otago rocks is well illustrated in the Bastion Hill at Benmore. From a little to its southward that dip is plainly seen. GEOLOGISTS’ OPINIONS Decaying vegetable and estuarine matter, chiefly molluscs, have been, by the action of tide and wind and ancient rivers deposited along the Taringaturi foothills, and it is in that area chiefly that prospecting should be done. Very little has so far been done to examine this area but Southland residents are surely lackadaisical if they are content to let the possibilities and probabilities of this wealth wait for perhaps distant exploitation. ... We have in New Zealand geologists who are noted for the soundness of their opinions. Professor James Park, F.G.S., in the New Zealand Geological Survey (Bulletin No. 23, Page 66) states: “A great thickness of middle. tertiary strata underlies the Oreti Plains dippin-; gently seaward as a flat monoclinal. Here also may exist pools of oil or accumulations of gas in profitable amount.” He also expresses his agreement with Professor Speight that it might be advisable to search for oil accumulations to the north of Winton. Professor Speight also mentioned the area to the westward of Femhill particularly. The North Island fields may have been so faulted by earth movements that little oil may be left, but there has been a different set of circumstances when the Hokonui system from the permian to the jurassic was formed. Professor Park (Geology of New Zealand, page 27) says this area contains no trace of contemporaneous volcanic activity. Southlanders, what about it?