SUMMARY
Characteristics of inclusions and forming
temperature of granitoids,
tin-wolfram and gold ores in Việt
Hoàng Sao
Inclusions are formed in
the crystallizing process of minerals. They have been subdivided into 3 groups:
solid, gas and liquid-mixed inclusions. Based on the forming time of inclusions
in comparision to containing them minerals, they can be subdivided into:
primary, primary-secondary and secondary inclusions. At present, the methods of
homogenization, cryometry, decrepitation and chemico-physical method have been
used in the study on inclusion types, aiming to determine the quantitative
chemico-physical parameters (temperature, composition, pressure) of the
mineral-forming environment, basing on this one can interprete precisely many
geological problems.
The study on different
types of inclusions in quartz of granitoids of the Trúc Khê - Núi Điệng
and Thiện Kế massifs and in veins of tin-wolfram, gold ores in Việt
- Granitoids of the Trúc Khê
- Núi Điệng and Thiện Kế massifs contain primary
crystallyzed and glassy inclusions having the forming temperature of from
600-700 to 980°C;
- Inclusions within
quartz of tin-wolfram ores in Việt Nam is abundant and diversified,
usually composed of 5 types of primary inclusions: gas, gas-liquid, polyphase,
liquid-carbonic and liquid-gas, formed in two stages: pneumatogene-hydrothermal
(300-500°C) at the pressure of 650-1300 At, and hydrothermal in high-medium
temperature (145-390°C) at the pressure of 750-1210 At. The highly concentrated
tin-wolfram ores, usually of industrial significance, were formed in the
hydrothermal stage of high-medium temperature (145-390°C);
- Inclusions within
quartz of primary gold type in Việt
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Người biên tập: Phan Trường Thị