Park, J. 1921 Geology and mineral resources of western Southland. Wellington: Government Printer. New Zealand Geological Survey bulletin 23 88 p.
Abstract: The area dealt with in this report lies to the west of the Takitimu Mountains, and includes the Waiau Valley and the country lying immediately to the westward of the chain of lakes drained by the Waiau River. A detailed examination was made of the Nightcaps, Wairio, and Ohai coalfields with the view of tracing the relationship existing between the coal measures of these areas and the Tertiary strata of the Waiau Valley. The western limits of the potential coal bearing Tertiary rocks were defined from Port Craig, on the south-west side of Te Waewae Bay, northward to Blue Cliff, Lake Hauroto, Lake Monowai, Lake Manapouri, and the upper end of Lake Te Anau. The present examination was intended to be supplementary to the electrification scheme recently initiated by the Southland Electrification Board. Special attention was devoted to the probable extension of the Nightcaps and Ohai coal-measures into the Waiau Valley, and to the occurrence of brick and pottery clays and of limestones and marls suitable for the manufacture of Portland cement. The research carried out by the author revealed the existence of large deposits of valuable clays, and of limestones and marls from which cement of good quality may be manufactured. It seems more than probable that cement-making will eventually develop into a flourishing Southland industry, the early stages of which will be stimulated by the demands of the electrification scheme. A considerable area of good brown coal exists in the Ohai basin, and potential coal-bearing areas occur in the Waiau Valley. A seam of hard brown coal was discovered on the eastern shore of Lake Te Anau, and pieces of coal that may lead to important discoveries were found on the west side of that lake. (auth)