Earth Science Frontiers ›› 2011, Vol. 18 ›› Issue (5): 67-77.

• Article • Previous Articles     Next Articles

Structurefluid related mineralization during the mylonitization process in the Hetai goldfield, Guangdong Province.

  

  1. 1. Key Laboratory of Mineralogy and Metallogeny； Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
    2. Key Laboratory of Marginal Sea Geology; South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
    3. The 11th department of Gold Army of Chinese Armed Police Force, Ningxiang 410600, China
    4. Gaoyao Hetai Gold Mine, Zhaoqing 526127, China
    5.  Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2011-06-10 Revised:2011-08-09 Online:2011-09-18 Published:2011-09-18

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Abstract:

A numerical modeling of the structurefluid process during mylonitization was conducted in order to investigate the possibility of gold mineralization related to mylonitization. Based on stress analysis and microstructural studies and comparison with modeling results, it is proposed that the study area was under compression in the direction of 108° during the formation of the mylonitized zones. The results of numerical modeling, together with previous studies, suggest that anomalous belts of volumetric strain increment are favorable for mylonitization and synmylonitization mineralization, and provide favorable site for later hydrothermal mineralization. It is proposed that mylonitization took place from 212 to 168 Ma at temperature from 300 to 500 ℃, and the synmylonitization mineralization process occurred from 197 to 168 Ma at temperature from 300 to 340 ℃. Uneconomic mineralization may have been produced during mylonitization, which was upgraded by later hydrothermal mineralization to form the Hetai gold deposit.

Key words:  the Hetai goldfield, mylonitized zone, dynamic circumstance, numerical modeling; , volumetric strain increment

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