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Bentonite. —The stipulation that bentonite must attain the minimum grade of 90 per cent, by the Sadler test before export is permitted has already brought results and the Australian market has already been partly recovered. During 1949, 456 tons of bentonite valued at £3,341 were produced, as compared with 624 tons valued at £4,462 in 1948. Serpentine. —There was again a substantial increase in the production of serpentine, 54,453 tons being produced, as against 38,637 tons in 1948. Of the 1949 production, 52,053 tons came from Piopio, near Te Kuiti, and 2,400 tons from Mossburn, in Southland. The use of serpentine-superphosphate as a fertilizer now seems established. Since 1941 to date, 297,481 tons of serpentine have been produced for this purpose. Dolomite. —Production of dolomite amounted to 4,210 tons in 1949, as against 6,912 in 1948. Of this amount, 622 tons were finely ground for use as a fertilizer in the cultivation of tobacco, the balance being sold in lump form for the manufacture of soluble-slag fertilizer. Since production commenced in 1936 at the deposit at Mount Burnett in the Collingwood district, 44,453 tons have been marketed. Magnesite.—From the magnesite-talc deposits of Upper Takaka, 559 tons of impure magnesite were obtained as compared with 540 tons in 1948. The magnesite was marketed in finely ground form for use as a fertilizer in the tobacco plantations of Nelson. Limestone. —Production of limestone for various uses has been continually expanding until in bulk it ranks second to coal and in value third to gold and coal, and the total production of limestone for the year 1949 again exceeded 1,500,000 tons. Of this total, limestone for use in agriculture was the greatest contributor, 1,100,126 tons being produced for this use in 1949, as against 1,091,299 tons in 1948. As in past years, the Southern Inspectorate District comprising Canterbury, Otago, and Southland was responsible for over two-thirds of this production, the balance coming from the North Island, except for a small tonnage from the Nelson - West Coast District. In the cement industry, 418,487 tons of limestone were used together with 30,879 tons of shale and 15,660 tons of silica sand to produce 250,026 tons of cement. There must be considerable increase in the production of materials for the manufacture of cement when the enlargement of cement-works is completed. Production of limestone for industrial uses amounted to 43,901 tons, of which the greater proportion was used for the manufacture of quicklime and slaked lime, 23,545 tons of these being produced. Other uses were the manufacture of soluble slag, the refining of sugar, and the dusting of coal-mines. Included in this total are 1,621 tons of chalk which were used for a variety of industrial uses. Pumice. —A total of 13,124 tons of pumice, of which 1,419 tons were exported, was produced in 1949. Corresponding figures for 1948 were 6,833 tons of which 1,735 tons were exported. Clay for Briclcs, Tiles, &c.—Production of clays for the manufacture of bricks, tiles, &c., amounted to 157,910 tons in 1949, as compared with 159,129 tons in 1948. Clays for Pottery, Fillers, &c —ln 1949, 14,672 tons of clay were produced for use in pottery and as fillers, &c. The corresponding figure for 1948 was 17,402 tons. Silica Sand. —During 1949, 20,401 tons of silica sand were obtained from deposits at Parengarenga, Hyde, Mount Somers, Geraldine, and Parapara, compared with 16,536 tons produced from the same deposits in 1948. The most important contributor to this total was the deposit at Parengarenga, from which 18,363 tons were obtained for use in glass-manufacture. Dimension Stone.—The production of stone for building and monumental work during 1949 amounted to 5,482 tons, as against 14,528 tons during 1948. This decrease is due entirely to reduction in the mining of Oamaru stone, only 1,241 tons of this stone being produced in 1949, as compared with 20,179 in 1948. Other types of stone produced included granite from Bluff, marble from Hanmer, sandstone from Charteris Bay, Canterbury, and bluestone from quarries in Otago and Canterbury.
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