Doole, M.H.; Watters, W.A.; Christie, A.B. 1989 Sheet QM438 Port Pegasus and part Sheet QM418 Bluff : geological resource map of New Zealand 1:250,000. [s.l.]: [s.n.]. New Zealand Geological Survey report M 155. 22 p.
Abstract: The Port Pegasus and part of Bluff map sheets described include Stewart Island and part of the offshore sedimentary basin known as the Great South Basin. Apart from small scale quarrying of aggregate materials, there is no significant extraction of geological resources on Stewart Island being carried out at present. Cassiterite and wolframite occur disseminated and in quartz lodes in a greisen developed in the contact zone between schist and underlying granite along to Tin Range. Small quantities of tin were mined between 1888 and the early 1900's but mostly from the associated alluvial deposits. A little gold was also won from alluvial deposits during this period. No new reserves of these commodities have been located since. Minor individual occurrences of galena, molybdenite, copper, platinum and beryl have been noted on the island and a stream sediment survey of the northwestern part located some areas of anomalous nickel values. Magnetite and ilmenite ironsand deposits are present on a few beaches and have been prospected at Doughboy Bay. Only a small part of the island has been prospected by modern geochemical and geophysical techniques and therefore some potential for undiscovered mineral deposits, particularly buried or "blind" deposits, remains. There is a shortage of accessible, easily worked aggregate for building and roading near the main settlement at Halfmoon Bay. Coarse-grained feldspar is present in pegmatite at several localities but is unlikely to be developed because of more accessible occurrences in Nelson Province. Oil seeping from a fault in Leask Bay may originate from the Great South Basin. Toroa-1, one of two oil prospecting wells drilled in the northwestern part of the Great South Basin within Sheet QM438 Port Pegasus, contained oil and gas shows (auth)