Fluidization: An Important Process in the Formation of the Qiyugou Au-bearing Breccia Pipes in Central China

作     者：ZHANG Yuanhou ZHANG Shihong Franco PIRAJNO 

作者机构：College of Earth Sciences Jilin University Changchun Jilin 130061 China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China Geological Survey of Western Australia 100 Plain Street Perth WA6004 Australia 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2007年第81卷第2期

页      面：226-238页

核心收录：

学科分类：081803[工学-地质工程] 0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：the National Natural Science Foundation of China (grant No. 40032010B) 

主　　题：fluidization breccia pipe gold mineralization Qiyugou Cretaceous Henan Qinling China 

摘      要：Fluidization processes based on experiments are reviewed to gain some useful insights and comparisons with those that occur in hydrothermal systems. Field and petrographic work, and microscope observation were carried out on samples from the Qiyugou Au-bearing breccia pipes from the East Qinling region, Henan Province. Evidence from macro- and micro-textures suggests that the style of breccias in the Qiyugou area can be grouped into three types： （1） jigsaw fit-stockwork texture, in which the interval between clasts is marked by fractures or filled with calcite or quartz veins; （2） larger breccias that are supported by smaller breccias, rock flour and alteration materials; in this type clasts moved over short distances, creating open spaces; （3） fluidized texture, where the clasts of different lithologies have rounded shapes. These observations are compared with those resulting from experiments on fluidization processes. The results of this comparison suggest that fluidization is an important geological process in the formation of the Qiyugou Au-bearing breccia pipes and gold mineralization. In addition, fluidization processes such as expansion, bubbling, slugging, channeling and spouting must have contributed to the formation of the pipes and were conducive to the development of gold mineralization. In the Qiyugou breccia pipes, gold mineralization occurs as disseminations, in stockwork veins, and open space infills. The ore zones form subparallel sheets that are nearly perpendicular to the walls of the pipes.