Standard laboratory procedures and remote sensing techniques were employed in the characterization of gold bearing rocks of the Paishanlou area. Results indicate that, the rocks were formed in an alteration complex of...Standard laboratory procedures and remote sensing techniques were employed in the characterization of gold bearing rocks of the Paishanlou area. Results indicate that, the rocks were formed in an alteration complex of medium temperature and pressure. The area was under intense polymetamorphism (ductile shearing, and hydrothermal metamorphism), which occurred along the deformation zone stretching from Jinzhou to Fuxin. The area bears some propylitic, phyllic (or sericitic) and argillic alteration styles. Gold minerals are contained in fine grained pyrite in silicified zones, and associated with metamorphosed Precambrian rocks. The host rock is composed of gneiss, mylonite and trondhjemite granite, and has a distinctive gold lead geochemical affinity.展开更多
Following the original approach of Bowden and Tabor and introducing state variables, an effective friction coefficient μ_e for solid particle erosion is defined as a combination of shearing term and ploughing term. I...Following the original approach of Bowden and Tabor and introducing state variables, an effective friction coefficient μ_e for solid particle erosion is defined as a combination of shearing term and ploughing term. In the case of continuous sliding, based on considering the interaction between asperities under certain condition, it is indicated that during the oblique impact of a hardened steel sphere against a mild steel target, a possible value of μ_e is 0.05, which was chosen in all of the calculations by Hutchings for consistency with both experiments and calculations. In the case of continuous ploughing, it is shown that the value of μ_e is a function of the impact process and the initial impact angle and is greater than 0.05 on an average for Hutchings' experiments. It is suggested that the variation of sliding, rolling and ploughing state at each instant in the impact process makes “the coefficient of friction” equal to 0.05 for Hutchings' experiments, and in general, makes the effective friction coefficient during particle impact on metal far less than the friction coefficient during simple continuous sliding on an average.展开更多
The gold-deposit of shearzone-type(GST)resulting predominantly from shearing is controlled by ductile shearzones,and its general characteristics are discussed in this paper.GST can be classified differently according ...The gold-deposit of shearzone-type(GST)resulting predominantly from shearing is controlled by ductile shearzones,and its general characteristics are discussed in this paper.GST can be classified differently according to its characteristics,and the the authors offer three ways,namely the classification based on the characterisics and genesis of ore-deposits,on the occurrence of shear zones,and on the formation conditions of shear zones.展开更多
基金This study was supported by the China Scholarship Council(GrantNo.160)National Nature Science Foundation of China(Grant No.400722006)the Key Task Project of Science and Technology of Liaoning Province(GrantNo.2001230001).
文摘Standard laboratory procedures and remote sensing techniques were employed in the characterization of gold bearing rocks of the Paishanlou area. Results indicate that, the rocks were formed in an alteration complex of medium temperature and pressure. The area was under intense polymetamorphism (ductile shearing, and hydrothermal metamorphism), which occurred along the deformation zone stretching from Jinzhou to Fuxin. The area bears some propylitic, phyllic (or sericitic) and argillic alteration styles. Gold minerals are contained in fine grained pyrite in silicified zones, and associated with metamorphosed Precambrian rocks. The host rock is composed of gneiss, mylonite and trondhjemite granite, and has a distinctive gold lead geochemical affinity.
文摘Following the original approach of Bowden and Tabor and introducing state variables, an effective friction coefficient μ_e for solid particle erosion is defined as a combination of shearing term and ploughing term. In the case of continuous sliding, based on considering the interaction between asperities under certain condition, it is indicated that during the oblique impact of a hardened steel sphere against a mild steel target, a possible value of μ_e is 0.05, which was chosen in all of the calculations by Hutchings for consistency with both experiments and calculations. In the case of continuous ploughing, it is shown that the value of μ_e is a function of the impact process and the initial impact angle and is greater than 0.05 on an average for Hutchings' experiments. It is suggested that the variation of sliding, rolling and ploughing state at each instant in the impact process makes “the coefficient of friction” equal to 0.05 for Hutchings' experiments, and in general, makes the effective friction coefficient during particle impact on metal far less than the friction coefficient during simple continuous sliding on an average.
文摘The gold-deposit of shearzone-type(GST)resulting predominantly from shearing is controlled by ductile shearzones,and its general characteristics are discussed in this paper.GST can be classified differently according to its characteristics,and the the authors offer three ways,namely the classification based on the characterisics and genesis of ore-deposits,on the occurrence of shear zones,and on the formation conditions of shear zones.
