: By means of kerogen purification, the proton induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA), the authors have studied the organic/inorganic occurrence modes of the metallic element...: By means of kerogen purification, the proton induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA), the authors have studied the organic/inorganic occurrence modes of the metallic elements of the Baiguoyuan silver-vanadium deposit hosted in black shale in Hubei Province, China. The result shows that Au, Hg and Ta have a strong tendency to occur organically, with more than 70% of these elements being associated organically. Se, Ga, Ag and Hf are partly associated with organic matter, with more than 20% of them occurring organically. Compared with the above elements, Zn, Cu, As and Sb are weakly associated organically, and tend to be enriched in kerogen. However, Mn, Th, U, V, Co, Cr, AI, Fe and Sc usually occur inorganically. Of the rare earth elements (REE), La, Ce, Tb, Dy, Yb and Lu have stronger ability to be associated with organic matter than Sm and Eu.展开更多
Baiguoyuan silver-vanadium deposit is generally thought to be of sedimentary-diagenetic origin. Based on the characteristics of barites, it is suggested that hydrothermal transformation has been involved in mineraliza...Baiguoyuan silver-vanadium deposit is generally thought to be of sedimentary-diagenetic origin. Based on the characteristics of barites, it is suggested that hydrothermal transformation has been involved in mineralization. The barites in black shale can be grouped into irregular ones which were formed during early diagenesis and tabular ones which were formed during late diagenesis. The tabular barites are replaced by pyrite and have formed a regular girdle around them. PIXE analysis states that Ag is greatly concentrated in pyrite replacement girdle. The girdle is the product of hydrothermal transformation. The transformation is one of the main mineralization stages of Baiguoyuan deposit.展开更多
By means of techniques such as inductively coupled plasma-mass spectrometry （ICP-MS） and X-ray fluorescence spectrometry （XRF）,REE geochemical characteristics and depositional environment of the black shales in Ba...By means of techniques such as inductively coupled plasma-mass spectrometry （ICP-MS） and X-ray fluorescence spectrometry （XRF）,REE geochemical characteristics and depositional environment of the black shales in Baiguoyuan Ag-V deposit,Xingshan,Hubei Province,were studied in this work. The black shales in a typical TC5 profile of Doushantuo Formation of upper Sinian period were obviously enriched in REE,especially in LREE. The REE patterns of the investigated samples normalized by Post Archean Australian Shale （PAAS） showed a flat or slight rightward inclination. The characteristic elements,their ratio and correlation diagrams showed that it should be hot-water deposit and the black shale in the study area was of a sedimentary origin. Redox sensitive metal elements pattern,trace elements index measurement in anoxic environment,Ce anomaly and δEu negative anomaly showed that the deposit environment of the black shales was a reducing and anoxic one and a slight change of the sea level could be identified. The samples relatively focused on the superimposed area of sedimentary rock and basalt in the diagram of La/Yb-ΣREE and La/Yb-Ce/La. So there might be accession of hot-water sedimentation during the period of the formation of the black rock series,mostly in normal terrigenous sedimentation with the participation of deep hot-water deposit.展开更多
文摘: By means of kerogen purification, the proton induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA), the authors have studied the organic/inorganic occurrence modes of the metallic elements of the Baiguoyuan silver-vanadium deposit hosted in black shale in Hubei Province, China. The result shows that Au, Hg and Ta have a strong tendency to occur organically, with more than 70% of these elements being associated organically. Se, Ga, Ag and Hf are partly associated with organic matter, with more than 20% of them occurring organically. Compared with the above elements, Zn, Cu, As and Sb are weakly associated organically, and tend to be enriched in kerogen. However, Mn, Th, U, V, Co, Cr, AI, Fe and Sc usually occur inorganically. Of the rare earth elements (REE), La, Ce, Tb, Dy, Yb and Lu have stronger ability to be associated with organic matter than Sm and Eu.
文摘Baiguoyuan silver-vanadium deposit is generally thought to be of sedimentary-diagenetic origin. Based on the characteristics of barites, it is suggested that hydrothermal transformation has been involved in mineralization. The barites in black shale can be grouped into irregular ones which were formed during early diagenesis and tabular ones which were formed during late diagenesis. The tabular barites are replaced by pyrite and have formed a regular girdle around them. PIXE analysis states that Ag is greatly concentrated in pyrite replacement girdle. The girdle is the product of hydrothermal transformation. The transformation is one of the main mineralization stages of Baiguoyuan deposit.
基金Project supported by the Key Scientific and Technological Project of Hubei Province, China (2007AA301C51)
文摘By means of techniques such as inductively coupled plasma-mass spectrometry （ICP-MS） and X-ray fluorescence spectrometry （XRF）,REE geochemical characteristics and depositional environment of the black shales in Baiguoyuan Ag-V deposit,Xingshan,Hubei Province,were studied in this work. The black shales in a typical TC5 profile of Doushantuo Formation of upper Sinian period were obviously enriched in REE,especially in LREE. The REE patterns of the investigated samples normalized by Post Archean Australian Shale （PAAS） showed a flat or slight rightward inclination. The characteristic elements,their ratio and correlation diagrams showed that it should be hot-water deposit and the black shale in the study area was of a sedimentary origin. Redox sensitive metal elements pattern,trace elements index measurement in anoxic environment,Ce anomaly and δEu negative anomaly showed that the deposit environment of the black shales was a reducing and anoxic one and a slight change of the sea level could be identified. The samples relatively focused on the superimposed area of sedimentary rock and basalt in the diagram of La/Yb-ΣREE and La/Yb-Ce/La. So there might be accession of hot-water sedimentation during the period of the formation of the black rock series,mostly in normal terrigenous sedimentation with the participation of deep hot-water deposit.
