Advertisement

Science in China Series D: Earth Sciences

, Volume 43, Issue 2, pp 113–121 | Cite as

Fluids double-fracturing genetic mechanism and mineralization of gold-copper of the breccia pipe at Qibaoshan in Shandong Province

  • Xingwang Xu
  • Xinping Cai
  • Dajun Qin
  • Jie Wang
  • Guanghe Liang
  • Xiaoyun Zhang
  • Lijin Liu
Article

Abstract

After studying the characteristics and special texture of the fluidogenous tectonics, mineral assemblage in the cemented vein between breccia and their special distribution, and stress analyzing the joint structures in and around the breccia pipe, it is found that the observed phenomena are caused by a new tectonic dynamic mechanics of fluid—double-fracturing caused by temperature and pressure of fluids and pulsating expansion. Under the actions of thermal stress and the pressure of fluids, thermal cracks and joints that developed along parts of the thermal cracks formed systematically in the rocks. Under these conditions, up-arching fracture zones that pulsatively expanded upward and cylindrical pressing breccia body were formed. Rocks at the peak of the pyramidal fractures zone break down instantly. Where the difference between pressure of fluids and the overburden pressure exceeded greatly the competence of the rocks, fluid junctions occurred and the velocity of the fluid flow increased as a result. Explosive body expanded upward in the shape of an inverse cone, cone-like explosive breccia body and cover-like shattering breccia body located on the upper part of the breccia pipe were ultimately formed. Gold-rich fluids were enriched and mineralized near the boiling surface in the lower part of the inverse cone-like explosive breccia body where temperature and pressure decreased rapidly, while copper-rich fluids were enriched and mineralized in the junction area where temperature and pressure were relatively high.

Keywords

breccia pipe double-fracturing of fluids genetic mechanism mineralization of gold-copper deposit Qibaoshan 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Bryant, D. G., Intrusive breccias associated with ore, Warren (Bisbee) Mining District, Arizona, Economic Geology, 1968, 63(1): 1.Google Scholar
  2. 2.
    Norton, D. L., Cathles, L. M., Breccia pipes, products of exsolved vapor from magmas, Economic Geology, 1973, 68(3): 540.CrossRefGoogle Scholar
  3. 3.
    Sharp, J. E., Cave Peak, a Molybdenum-Mineralized Breccia Pipe Complex in Culberson County, Texas, Economic Geology and the Bulletin of the Society of Economic Geologists, 1979, 74(3): 517.Google Scholar
  4. 4.
    Norman, D. I., Sawkins, F. J., The Tribag breccia pipes: Precambrian Cu-Mo deposits, Batchawana Bay, Ontario, Economic Geology, 1985, 80(5): 1593.Google Scholar
  5. 5.
    Barker, E. M., Andrew, A. S., Geologic, fluid inclusion, and stable isotope studies of the gold-bearing breccia pipe at Kidston, Queensland, Australia, Economic Geology, 1991, 86: 810.Google Scholar
  6. 6.
    Chen, J., Tang, Y. L., Metallogenic mechanism on Ag-polymetallic deposits of hydrothermal explosion at Zhijiadi in Lingqiu County in Shanxi Province, Geology and Prospecting (in Chinese), 1993, 29(11): 16.Google Scholar
  7. 7.
    Zhang, Z. F., General feature and genetic mechanism of crypto-explosive breccias, Geological Science and Technology Information (in Chinese), 1991, 10(4): 1.Google Scholar
  8. 8.
    Hu, C. Q., Feng, Z. H., Wang, L. J. et al., Study on the features of intermediate-acid cryptoexplosion breccia and subvolcanic rocks (ultra-hypabyssal rocks) and their relation with mineralization—Taking Xinmin-Jitang copper and silver mining area at Guigang in Guangxi province as an example, Geology and Prospecting (in Chinese), 1997, 33(4): 1.Google Scholar
  9. 9.
    Qiu, D. D., Kong, L. G., Geological and chemical characteristics of the gold-copper deposits in breccia pipe at Qibaoshan in Shandong Province, Geology and Prospecting (in Chinese), 1986, 22(5): 7.Google Scholar
  10. 10.
    Zhou, B. H., The Qibaoshan hidden explosive breccia pipe: Its features and relation to mineralization, Geology and Prospecting (in Chinese), 1990, 26(5): 26.Google Scholar
  11. 11.
    Wang, Y., Geological characteristics and origin of Qibaoshan gold deposit in Shandong Province, Geological Review (in Chinese), 1991, 37(4): 330.Google Scholar
  12. 12.
    Zhang, L. Y., Cheng, M. Q., Geochemical characteristics of Qibaoshan Au-Cu deposit in Shandong Province and its genesis, Contributions to Geology and Mineral Resources Research (in Chinese), 1996, 11(1): 18.Google Scholar
  13. 13.
    Chen, D. J., Exploration indicative features of specularite, Geology and Prospecting (in Chinese), 1988, 24(3): 10.Google Scholar
  14. 14.
    Xie, G. D., Relations between the hydrothermal boiling action and gold mineralization and their significances, Geological Science and Technology Information (in Chinese), 1993, 12(3): 61.Google Scholar
  15. 15.
    Qiu Jianshen, Characteristics of volcanic rock and subvolcanic rock in the Mugearite Province in Mesozoic era and relative mineralization of gold (copper) deposit in the eastern part of China, Doctoral dissertation, Nanjing University, 1992.Google Scholar

Copyright information

© Science in China Press 2000

Authors and Affiliations

  • Xingwang Xu
    • 1
  • Xinping Cai
    • 1
  • Dajun Qin
    • 1
  • Jie Wang
    • 1
  • Guanghe Liang
    • 1
  • Xiaoyun Zhang
    • 2
  • Lijin Liu
    • 2
  1. 1.Institute of Geology and Geophysics, Chinese Academy of SciencesBeijingChina
  2. 2.Qibaoshan Gold Corporation, Shandong ProvinceWuliangChina

Personalised recommendations