It has become clear in recent years that the important substitutional impurities in diamond are nitrogen,hydrogen and boron(Bibby,D.M.,1982).The physical and chemical properties of diamond are determined by the conten...It has become clear in recent years that the important substitutional impurities in diamond are nitrogen,hydrogen and boron(Bibby,D.M.,1982).The physical and chemical properties of diamond are determined by the content and form of occurence of nitrogen based on which diamonds are generally classified.The well-known experiments concerning the mutual transformation of the forms the origin of diamond.by Evans.T.Et al.(1982) have provided a theoretic basis for the origin of diamond.Since 1979,spectroscopic investigation of natural diamonds from different areas in china has been carried out using UV-visible and IR spectrophotometer,EPR and cathodoluminescence techniques.We have conducted the classification of natural cathodoluminescence techniques.We have conducted the classification of natural diamonds in China and studies on the forms of nitrogen and hydrogen,the radiation damage and their geological implications.Spectroscopic characteristics of natural diamonds in china and their geological implications are discussed in this paper.展开更多
Experimental data on cathodeluminescence of 34 individual specimens of naturallyoccurring apatite differring in the mode of occurrence are presented in this paper.In accordance with the characteristic distribution of ...Experimental data on cathodeluminescence of 34 individual specimens of naturallyoccurring apatite differring in the mode of occurrence are presented in this paper.In accordance with the characteristic distribution of the bands and lines of apatite specimens,it has been confirmed that RE ions Sm^2+,Dy^3+,En^2+,etc.,are the main activators for the cathodeumineseence of apatite.In conjunction with the crystallological study.a priliminary investigation into the mechanism for apatite cathodelnminescence has been made as well.The author has suggested that the cathodelumineseence of apatite may be attributed to the replacement of Mn at the site of Can by Mn^2+,and the luminous colour seems to have no direct,simple correlation with that of the crystal itsself.展开更多
Loess of China, regardless of its ageexhibites similarity in the surface textures of silt quartz grains, all of them having conchoidal fractures, flat cleavage planes(or plates) and mechanical cracks, and having been ...Loess of China, regardless of its ageexhibites similarity in the surface textures of silt quartz grains, all of them having conchoidal fractures, flat cleavage planes(or plates) and mechanical cracks, and having been rewrked by silica precipitation and chemical dissolution. Silica precipitation an different-degree chemical etching and dissolution are commonly found on thes silt quartz grains indicating that they would be separated from source rocks, such as granite, gneiss, etc. ; or they might have been subjected to relatively long weathering in situ before transported to loessic accumulation areas; or they probably underwent diagenesis when brought into the sedimentation system, followed by weathering and erosion, and then transported to loess accumulation areas. It is evident from the relationship between loess of China, deserts and Gobi, loessic cimposition and its regional distribution that MesozoicCenozoic land detrital sediments widely spreaded in the Ordos and Alxa regions are the principal material source of loessic materials in China.展开更多
Six clay mineral phases are recognized by means of electron microscope examination in a drilling profile in the eastern part of the Hobei Plain. Based on the relationship between these clay mineral phases, strata in t...Six clay mineral phases are recognized by means of electron microscope examination in a drilling profile in the eastern part of the Hobei Plain. Based on the relationship between these clay mineral phases, strata in this profile are divided into two groups, i.e., the upper and the lower groups. Five subgroups can be further distinguished within the lower group. The evolution of clay mineral phases provides indication of %he palaeoclimatic variation during this geological period.展开更多
It is well known that nitrogen is a major impurity in diamond because it can substitute the carbon in the diamond lattice. Hence diamonds may be classified as TypeⅠor Ⅱ based on the nitrogen content. The diamonds wi...It is well known that nitrogen is a major impurity in diamond because it can substitute the carbon in the diamond lattice. Hence diamonds may be classified as TypeⅠor Ⅱ based on the nitrogen content. The diamonds with higher nitrogen content are classified into Type Ⅰ. Diamonds in which nitrogen is mainly present in aggregated form are put in Type Ia, whercas those in which nitrogen is mainly present in dispersed and isolated form into Type Ib. Synthetic diamonds often belong to Type Ib. However,展开更多
Recently mineral inclusions and diamonds containing these inclusions are divided into three suites: the peridotite, the eclogite and the late crystallizing megacryst suites by ways of the mineralogical and chemical co...Recently mineral inclusions and diamonds containing these inclusions are divided into three suites: the peridotite, the eclogite and the late crystallizing megacryst suites by ways of the mineralogical and chemical composition, and the isotopic characteristic of inclusions of diamonds. Since the 1960s some odd investigations about the mineral inclusions of diamonds were carried out in China. This is the first re-展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘It has become clear in recent years that the important substitutional impurities in diamond are nitrogen,hydrogen and boron(Bibby,D.M.,1982).The physical and chemical properties of diamond are determined by the content and form of occurence of nitrogen based on which diamonds are generally classified.The well-known experiments concerning the mutual transformation of the forms the origin of diamond.by Evans.T.Et al.(1982) have provided a theoretic basis for the origin of diamond.Since 1979,spectroscopic investigation of natural diamonds from different areas in china has been carried out using UV-visible and IR spectrophotometer,EPR and cathodoluminescence techniques.We have conducted the classification of natural cathodoluminescence techniques.We have conducted the classification of natural diamonds in China and studies on the forms of nitrogen and hydrogen,the radiation damage and their geological implications.Spectroscopic characteristics of natural diamonds in china and their geological implications are discussed in this paper.
文摘Experimental data on cathodeluminescence of 34 individual specimens of naturallyoccurring apatite differring in the mode of occurrence are presented in this paper.In accordance with the characteristic distribution of the bands and lines of apatite specimens,it has been confirmed that RE ions Sm^2+,Dy^3+,En^2+,etc.,are the main activators for the cathodeumineseence of apatite.In conjunction with the crystallological study.a priliminary investigation into the mechanism for apatite cathodelnminescence has been made as well.The author has suggested that the cathodelumineseence of apatite may be attributed to the replacement of Mn at the site of Can by Mn^2+,and the luminous colour seems to have no direct,simple correlation with that of the crystal itsself.
文摘Loess of China, regardless of its ageexhibites similarity in the surface textures of silt quartz grains, all of them having conchoidal fractures, flat cleavage planes(or plates) and mechanical cracks, and having been rewrked by silica precipitation and chemical dissolution. Silica precipitation an different-degree chemical etching and dissolution are commonly found on thes silt quartz grains indicating that they would be separated from source rocks, such as granite, gneiss, etc. ; or they might have been subjected to relatively long weathering in situ before transported to loessic accumulation areas; or they probably underwent diagenesis when brought into the sedimentation system, followed by weathering and erosion, and then transported to loess accumulation areas. It is evident from the relationship between loess of China, deserts and Gobi, loessic cimposition and its regional distribution that MesozoicCenozoic land detrital sediments widely spreaded in the Ordos and Alxa regions are the principal material source of loessic materials in China.
文摘Six clay mineral phases are recognized by means of electron microscope examination in a drilling profile in the eastern part of the Hobei Plain. Based on the relationship between these clay mineral phases, strata in this profile are divided into two groups, i.e., the upper and the lower groups. Five subgroups can be further distinguished within the lower group. The evolution of clay mineral phases provides indication of %he palaeoclimatic variation during this geological period.
文摘It is well known that nitrogen is a major impurity in diamond because it can substitute the carbon in the diamond lattice. Hence diamonds may be classified as TypeⅠor Ⅱ based on the nitrogen content. The diamonds with higher nitrogen content are classified into Type Ⅰ. Diamonds in which nitrogen is mainly present in aggregated form are put in Type Ia, whercas those in which nitrogen is mainly present in dispersed and isolated form into Type Ib. Synthetic diamonds often belong to Type Ib. However,
基金Project supported by the National Natural Science Foundation of China.
文摘Recently mineral inclusions and diamonds containing these inclusions are divided into three suites: the peridotite, the eclogite and the late crystallizing megacryst suites by ways of the mineralogical and chemical composition, and the isotopic characteristic of inclusions of diamonds. Since the 1960s some odd investigations about the mineral inclusions of diamonds were carried out in China. This is the first re-
