| 其他摘要 | The Murantau-type gold deposit is an important type of deposits in the world. The Sawaya'erdun gold deposit, located in the west of Xinjiang, is one of Murantau-type gold deposits found in China in recent years. Since the dicovery of the First Murantau-type gold deposit in southwestern Tianshan Mountains, a large amount of investigations on geological background, ore component, wallrock alteration, occurrence of gold etc. have been carried out and lots of research have been achieved. On the basis of previous research, the author has undertaken the research on isotopes of hydrogen, oxygen, carbon, sulphur, lead, silicon, Rb-Sr, Ar-Ar and carried out fluid inclusion studies including fluid inclusion phase assemblages, microthermometry, Laser-Raman spectrometry of single inclusion. Through the above work, some data and photos of fluid inclusions were taken, and the major achievements are obtained as following: Carrying out a large amount of study on the isotope characters of hydrogen, oxygen, carbon, sulphur, lead, silicon, thus there is relatively overall understanding in the question of source of mineralized substances and ore-forming mechanism of Xinjiang Sawaya'erdun Murantau-type gold deposits. 1. Undertaking isotopic geochronological study on Ar-Ar, adopted the fast-neutron activation dating technique to test 40Ar-39Ar age of quartz from Au-bering quartz veinlet ore in the deposit, and well-defined plateau age of 210.59 Ma ±1.92 Ma, the lowest apparent age of 208.07 Ma+1.22 Ma, and isochron age of 207.14 Ma+1.92 Ma. The age values are close to crystallizing age of the quartz. Combined with other geochronological data and the geological features, it is concluded that the Indo-Chinese epoch may be the principle mineralization period for gold deposits in the southwestern Tianshan Mountains. 2.The typical phase assembladges of the fluid inclusions show that there are mainly NaCl-HbO type of inclusions with V+L phases and CCVrich type of inclusions with L_(CO2), L_(CO2)+L, V_(CO2)+L, V_(CO2)+L_(CO2)+L, or V_(CO2) phases respectively. The CO_2-rich 'inclusions and normal NaCl+H2O inclusions are commonly observed in same samples with the same homogenization temperature (Th). 4. A large amount of microthermometric data of fluid inclusions indicates that the homogenization temperatures of fluid inclusions in quartz vein from early stage are mainly varied from 270 to 320 ℃, higher than that of main stage which varied from 170 to 250 ℃. 5. Laser-Raman analysis for individual inclusions indicate that the inclusions contain CO_2, N_2, CH_4 respectively. |
修改评论