The Elements of economic geology

Bibliographic data

Monograph

Identifikator:: 1773832379

URN:: urn:nbn:de:zbw-retromon-172798

Document type:: Monograph

Author:: Gregory, John W. http://d-nb.info/gnd/11683014X

Title:: The Elements of economic geology

Place of publication:: London

Publisher:: Methuen

Year of publication:: 1928

Scope:: XIV, 312 S.; graph. Darst.

Digitisation:: 2021

Collection:: Economics Books

Usage license:: Get license information via the feedback formular.

Chapter

Document type:: Monograph

Structure type:: Chapter

Title:: Part II. Ore deposits

Collection:: Economics Books

ORES OF TIN AND TUNGSTEN 79 comes from scheelite, calcium tungstate (CaWO,). Wol- framite is mostly found in quartz-veins in granite; it is of Pneumatolytic origin and is associated with quartz, tour- maline, topaz, fluorite, and tin. One of the best-known fields is Tavoy in South Burma; wolframite occurs there in schists which during the uplift of the Altaid Mountains at the end of the Palzozoic were intruded by granite and Pheumatolytic quartz-veins. According to Morrow Camp- bell, tin is present in the lower part and wolframite in the upper part of these veins. Wolframite is sometimes mined from the lodes, but most of it is obtained by washing gravel or decomposed: country rock; these deposits often vield 3% lb. of wolframite per cubic yard. CriNese Deposits—Wolframite occurs under similar geological conditions in the province of Kiangsi in Southern China. The ore there was at first obtained from alluvial deposits, but some quartz-lodes in granite are now being mined and also yield some tin. China is now the largest producer of tungsten, and in some recent years has supplied half the world’s output. Wolframite occurs in Siam, the Malay Peninsula, and the Chillagoe and Mt. Carbine fields in Queensland. One large deposit of the iron tungstate variety of wolframite occurs in Colorado. . The chief deposits of scheelite are of Kainozoic age and occur nthe western mountains of the United States, especially In California ; the scheelite occurs with garnet and epidote n limestones altered by granodiorite intrusions. Wolframite and scheelite both have nearly the same Specific gravity as cassiterite; but wolframite is easily Separated magnetically, and scheelite, for which this process 1S not available, does not often occur with tin oxide. The Shot supplies of tungsten come from China, Burma, and the od States, the combined yield of Spain and Portugal tor 8, fourth in quantity. The output increased from 7800 io 0 1913 to 21,600 tons in 1017. The material is sold ang to the percentage of tungstic acid (WOg); the pric: ord quality contains 65 per cent. of that oxide ; the dur. as usually varied between 25s. to 35s. per unit, though pe the War the output rose to over 30,000 tons in the Te and the price to 60s. per unit (or nearly £200 per ton); ’ 924 the output fell to 5500 tons and the price to as low S 0s. 6d. per unit.

Access restriction

Copyright

fullscreen: The Elements of economic geology

Monograph

Chapter

Table of contents

Download

Monograph

Chapter

This page

Image fragment

Citation links

Citation recommendation