Investigations of the acid volcanic rocks in New• Zealand have shown that the must promising perlite deposits are the glassy rhyolites of the Taupo-Rotorua and Tuirua districts. Tl,c Lest-grade rock is at Ongaroto, Maroa, Tairua, and Lake lfotoma. Large quantities of poorer.grade pcrlite arc at Ngangiho, Puke• tar.ua, and Round Hill. Methods used in the laboratory for evaluating local pe rlite rocks arc described and the results of expansion trials tabulated.
Ketersediaan
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Pusat Sumber Daya Mineral, Batubara dan Panas Bumi - Jln. Soekarno Hatta No. 444, Bandung, Jawa Barat
PMB LU 1954 - 2