In:
Bulletin de Minéralogie, PERSEE Program, Vol. 105, No. 1 ( 1982), p. 11-19
Abstract:
A large number of magnetite crystals from a fault zone — Gongchangling, China — have been studied from different point of view : grain-size distribution, crystal habit, twin morphology, natural etching features on {111}, chemical and physical properties, inclusion of other minerals, as well as microstructures of defects. A detailed statistics on the degree of departure of the crystals from a regular morphology and on the various morphological types of twins suggests a synkinematic crystallization of the magnetite under shearing stresses. This hypothesis is supported further on by the TEM observation of antiphase domains, linear dislocations, unit-cell twinnings and other defects. Decrepitation temperatures of fluid inclusions, the nature of cogenetic minerals, the etching features and δO¹⁸values all plead for a pneumatelytic origin of the magnetite connected with the magmatic activity of Proterozoic granites. This study gives the first keys to unravel the metallogenesis of the rich iron ores in Gongchangling.
Type of Medium:
Online Resource
ISSN:
0180-9210
DOI:
10.3406/bulmi.1982.7581
Language:
French
Publisher:
PERSEE Program
Publication Date:
1982
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