420 Transactions. — Geology. 



The Buller Coalfield alone is estimated to contain 140,000,000 

 tons of good bituminous coal ; the West Wanganui Coalfield, 

 25,000,000 tons of pitch-coal and 12,000,000 tons of brown 

 coal ; while the Brunner Mine contains about 4,000,000 tons. 

 To the sum of these must be added the coal contained in the 

 Collingwood Coalfield, which has an area of about twenty 

 square miles. The output of coal for the Nelson District is 

 about 200,000 tons per annum. 



Gold, the next mineral of unportance, is found in many 

 parts of the Nelson District, Collingwood and the West Coast 

 having so far yielded the largest quantities. The gold in 

 the Nelson District is usually found in the gravels and drifts 

 which have been derived from the older metamorphic rocks. 

 These rocks stratigraphically underlie the Maitai formation, 

 and are coloured sepia on the map. The gravels and drifts in 

 which the gold is usually found are coloured red or yellow, 

 red representing the older gravels, and yellow the more recent 

 formations. On the map only the larger deposits of these 

 formations have been represented. There are innumerable 

 patches of recent gravels found in almost every river- valley 

 of the district, which could not possibly be represented on a 

 map of so small a scale. It must be borne in mind, however, 

 that only the gravels from the older formations are auriferous. 

 The Maitai slates, for example, as far as is known at present, 

 are not gold-bearing ; consequently, the gravels derived from 

 them are not auriferous. The gold exported from the Nelson 

 District last year was valued at £16,000, while since 1857 to 

 the present time six million pounds' worth of gold has been 

 obtained from the Collingwood district alone. Copper and 

 chrome are found in many parts of the Dun Mountain mineral 

 belt, but owing probably to the want of scientific prospecting 

 these minerals have not yet been discovered in sufficient quan- 

 tities to pay for working. 



Argentiferous galena — that is, silver-bearing lead-ore — has 

 been discovered at the Owen and at Wangapeka; and at Col- 

 lingwood silver, lead, zinc, nickel, antimony, copper, bismuth, 

 and iron are known to exist, in addition to the gold already 

 referred to. Plumbago is also found in the Collingwood dis- 

 trict, but not sufficiently pure for commercial purposes. The 

 iron in the Collingwood district belongs to the class of ore 

 known as limouite, or brown hsematite. This substance is at 

 present made into paint ; but probably the time is not very 

 far distant when iron will be smelted fi-om these valuable 

 deposits of ore. At the Hope Saddle an interesting iron 

 compound is found ; it is known as vivianite. It is an iron- 

 phosphate, and is of a bluish colour. A specimen of it will 

 be found upon the table, together with specimens of all the 

 rocks and minerals mentioned in this paper. 



