2004 Vol. 29, No. 1
Display Method:
2004, 29(1): 1-6.
PDF 222KB
Abstract:
Stable oxygen and carbon isotope records from ODP Site 1143 (9°21.72′N, 113°17.11′E, 2 772 m) in the southern South China Sea (SCS) are presented for the benthic foraminifers Cibicidoides wuellerstorfi and Uvigerina peregerina in 64 samples. The results show that the average δ18O difference between Cibicidoides wuellerstorfi and Uvigerina peregerina of 64 samples at Site 1143 is (0.614±0.07)×10-3, close to 0.64×10-3 of the standard oxygen isotopic difference in the Atlantic and the east Pacific, whereas the average δ13C difference of these two species at Site 1143 is (0.692±0.04)×10-3, much lighter than 0.9×10-3 of the standard carbon isotopic difference in the Atlantic and the east Pacific. The lighter value of δ13C difference at Site 1143 may be caused by the low productivity in reef areas which had decreased the δ13C difference between the depositions and the sea water. This test at Site 1143 provides an adjustive standard of oxygen and carbon isotope values between benthic foraminiferal Cibicidoides wuel-lerstorfi and Uvigerina peregerina for the paleoceanographic study in the South China Sea and even in the west Pacific.
Stable oxygen and carbon isotope records from ODP Site 1143 (9°21.72′N, 113°17.11′E, 2 772 m) in the southern South China Sea (SCS) are presented for the benthic foraminifers Cibicidoides wuellerstorfi and Uvigerina peregerina in 64 samples. The results show that the average δ18O difference between Cibicidoides wuellerstorfi and Uvigerina peregerina of 64 samples at Site 1143 is (0.614±0.07)×10-3, close to 0.64×10-3 of the standard oxygen isotopic difference in the Atlantic and the east Pacific, whereas the average δ13C difference of these two species at Site 1143 is (0.692±0.04)×10-3, much lighter than 0.9×10-3 of the standard carbon isotopic difference in the Atlantic and the east Pacific. The lighter value of δ13C difference at Site 1143 may be caused by the low productivity in reef areas which had decreased the δ13C difference between the depositions and the sea water. This test at Site 1143 provides an adjustive standard of oxygen and carbon isotope values between benthic foraminiferal Cibicidoides wuel-lerstorfi and Uvigerina peregerina for the paleoceanographic study in the South China Sea and even in the west Pacific.
2004, 29(1): 7-14.
Abstract:
Planktonic foraminifers from ODP Site 1143, southern South China Sea (SCS), were analyzed to reveal their response to glacial cycles in the past 2.1 Ma. Pulleniatina obliquiloculata, a widely-accepted indicator of the Kuroshio, shows completely reverse fluctuations, with high abundance in glacials, in southern SCS to those in the Okinawa trough and northern SCS since the Mid-Pleistocene Revolution (MPR). Before the MPR, P.obliquiloculata is abundant in interglacial intervals. Cross-spectral and phase analyses between P.obliquiloculata and δ18O confirmed the observations depicted above. The authors ascribed the transition of P.obliquiloculata's response to glacial cycles in southern SCS to a profound change in the regional upper ocean structure, probably related to glacial separation of the southern SCS from the Indian water and to higher surface salinity during glacial times after the MPR.
Planktonic foraminifers from ODP Site 1143, southern South China Sea (SCS), were analyzed to reveal their response to glacial cycles in the past 2.1 Ma. Pulleniatina obliquiloculata, a widely-accepted indicator of the Kuroshio, shows completely reverse fluctuations, with high abundance in glacials, in southern SCS to those in the Okinawa trough and northern SCS since the Mid-Pleistocene Revolution (MPR). Before the MPR, P.obliquiloculata is abundant in interglacial intervals. Cross-spectral and phase analyses between P.obliquiloculata and δ18O confirmed the observations depicted above. The authors ascribed the transition of P.obliquiloculata's response to glacial cycles in southern SCS to a profound change in the regional upper ocean structure, probably related to glacial separation of the southern SCS from the Indian water and to higher surface salinity during glacial times after the MPR.
2004, 29(1): 15-20.
Abstract:
During recent 20 years, the field of ancient DNA research has experienced a rapid development. Authentic DNA sequences from ancient human remains have provided very important information on human evolution, blood relationship and migration, making ancient DNA research an important field of molecular anthropology. This study illustrates ancient DNA extraction, amplification and sequencing of 6 000-year-B.P. Yangshao Culture ancient human remains collected from first and second phase culture beds at Jiangzhai Site, Lintong, Shaanxi Province. Three 169 bp fragments from the hypervariable region Ⅰ in the mitochondrial genome have been obtained and authenticated. These ancient DNA sequences carry two point mutations in comparison with homologeous sequence of the modern Xi'an people's. Moreover, the authenticity of the ancient DNA sequence was obtained through the replication experiments in two different laboratories in China University of Geosciences and Zhongshan University as well as phylogenetic analysis. Among the 6 samples from the Jiangzhai Site, three of them yielded authenticated ancient DNA sequence. The 50% success ratio is higher than that of general ancient DNA research materials previously reported in the literature, indicating the potential for further ancient DNA studies on human remains of Yangshao Culture for the purpose of blood relationship among different archaeological sites and human evolution.
During recent 20 years, the field of ancient DNA research has experienced a rapid development. Authentic DNA sequences from ancient human remains have provided very important information on human evolution, blood relationship and migration, making ancient DNA research an important field of molecular anthropology. This study illustrates ancient DNA extraction, amplification and sequencing of 6 000-year-B.P. Yangshao Culture ancient human remains collected from first and second phase culture beds at Jiangzhai Site, Lintong, Shaanxi Province. Three 169 bp fragments from the hypervariable region Ⅰ in the mitochondrial genome have been obtained and authenticated. These ancient DNA sequences carry two point mutations in comparison with homologeous sequence of the modern Xi'an people's. Moreover, the authenticity of the ancient DNA sequence was obtained through the replication experiments in two different laboratories in China University of Geosciences and Zhongshan University as well as phylogenetic analysis. Among the 6 samples from the Jiangzhai Site, three of them yielded authenticated ancient DNA sequence. The 50% success ratio is higher than that of general ancient DNA research materials previously reported in the literature, indicating the potential for further ancient DNA studies on human remains of Yangshao Culture for the purpose of blood relationship among different archaeological sites and human evolution.
2004, 29(1): 21-24.
Abstract:
A group of pterosaur trackway is preserved in site 1 of dinosaur tracksite of Yanguoxia, Yongjing County, Gansu Province. The pterosaur trackway is the first one discovered in China. The pterosaur trackway is quadrupedal, with wide gauge. Manus impression is strongly asymmetrical, digitigrade, tridactyl, with three digits impression showing outward rotation; digit Ⅱ is the shortest while digit Ⅳ is the largest. And digit Ⅳ subtends an angle of about 160°-180° relative to the trackway axis. Pes impression is sub-rectangular in shape which is three times longer than the width and tetradactyl with digits Ⅱ and Ⅲ longer than digits Ⅰ and Ⅳ, and outward rotation of about 30° relative to trackway axis. Based on the character of pterosaur tracks, the authors assign them to a new ichnosp. The sedimentology of this site reflects a paleoenvironment of lake shoreline where pterosaur tracks occur.
A group of pterosaur trackway is preserved in site 1 of dinosaur tracksite of Yanguoxia, Yongjing County, Gansu Province. The pterosaur trackway is the first one discovered in China. The pterosaur trackway is quadrupedal, with wide gauge. Manus impression is strongly asymmetrical, digitigrade, tridactyl, with three digits impression showing outward rotation; digit Ⅱ is the shortest while digit Ⅳ is the largest. And digit Ⅳ subtends an angle of about 160°-180° relative to the trackway axis. Pes impression is sub-rectangular in shape which is three times longer than the width and tetradactyl with digits Ⅱ and Ⅲ longer than digits Ⅰ and Ⅳ, and outward rotation of about 30° relative to trackway axis. Based on the character of pterosaur tracks, the authors assign them to a new ichnosp. The sedimentology of this site reflects a paleoenvironment of lake shoreline where pterosaur tracks occur.
2004, 29(1): 25-30.
Abstract:
The rock series of the Cenozoic volcanic rocks include high-K calc-alkaline (HK-CA) series and shoshonite (SHO) series in the source region of the Yangtze River. The HK-CA rocks were formed in Eocene and the SHO rocks were formed in Neogene. Generally speaking, rocks with high content of alkali and K2O are enriched in LILE and with high abundance of REE, high ratio of LREE/HREE. The HK-CA rocks have more SiO2, Al2O3 and less K2O, TiO2, P2O5, MgO, FeO, ∑REE, HFSE, ISr than SHO, and show no Eu negative anomalies, distinguishing from SHO that show light Eu negative anomalies. Therefore, the HK-CA series belong to crust-derived magma series and are originated from melting of an eclogitic lower crust; the SHO series belong to mantle-derived magma series and are originated from melting of (EMⅡ) mantle. The Cenozoic volcanic rocks were formed in back-collision tectonic environment, and both HK-CA and SHO series magmas should be generated at the late stage of collision process, that is, when the collision changed from compression then to strike-slip movement, the SHO rocks occurred following HK-CA rocks.
The rock series of the Cenozoic volcanic rocks include high-K calc-alkaline (HK-CA) series and shoshonite (SHO) series in the source region of the Yangtze River. The HK-CA rocks were formed in Eocene and the SHO rocks were formed in Neogene. Generally speaking, rocks with high content of alkali and K2O are enriched in LILE and with high abundance of REE, high ratio of LREE/HREE. The HK-CA rocks have more SiO2, Al2O3 and less K2O, TiO2, P2O5, MgO, FeO, ∑REE, HFSE, ISr than SHO, and show no Eu negative anomalies, distinguishing from SHO that show light Eu negative anomalies. Therefore, the HK-CA series belong to crust-derived magma series and are originated from melting of an eclogitic lower crust; the SHO series belong to mantle-derived magma series and are originated from melting of (EMⅡ) mantle. The Cenozoic volcanic rocks were formed in back-collision tectonic environment, and both HK-CA and SHO series magmas should be generated at the late stage of collision process, that is, when the collision changed from compression then to strike-slip movement, the SHO rocks occurred following HK-CA rocks.
2004, 29(1): 31-38.
Abstract:
According to the geological characteristics, the mafic dykes in Huangling area mainly include diabase and diabase-prophyrite, with nearly NEE trend and NNW trend. Geochemical characteristics of the dykes indicate that they are sub-alkaline basalt formed in WPB. The low Mg#(Mg#=100×MgO/(MgO+0.9×TFe2O3))shows the magma for the dykes was highly evolutionary. The depletion in Nb and Ta, and the enrichment in Pb indicate that the mafic dykes are contaminated by crustal material. All these suggest that it may be the product of remelted materials from mantle source, which had been metasomatismed by the fluid in subduction zone, under the extensional circumstance. Based on the previous geochronological researches, it is concluded that the mafic dyke swarms intruded at about 770 Ma and may be related to the breakup of the Rodinia supercontinent.
According to the geological characteristics, the mafic dykes in Huangling area mainly include diabase and diabase-prophyrite, with nearly NEE trend and NNW trend. Geochemical characteristics of the dykes indicate that they are sub-alkaline basalt formed in WPB. The low Mg#(Mg#=100×MgO/(MgO+0.9×TFe2O3))shows the magma for the dykes was highly evolutionary. The depletion in Nb and Ta, and the enrichment in Pb indicate that the mafic dykes are contaminated by crustal material. All these suggest that it may be the product of remelted materials from mantle source, which had been metasomatismed by the fluid in subduction zone, under the extensional circumstance. Based on the previous geochronological researches, it is concluded that the mafic dyke swarms intruded at about 770 Ma and may be related to the breakup of the Rodinia supercontinent.
2004, 29(1): 39-44.
Abstract:
Two silicate glass samples at basaltic composition region, which are near the cotectic-line in Ab-An-Di phase diagram, were studied by high-temperature Raman spectroscopy using pulsed semiconductor laser and time-resolved detection technique from 298 K to 1 673 K. Temperature-dependent characteristic spectra and phase transition of glass, crystal and melt were observed. It is obvious that there exist some differences between the structure of glass and melt. The heredity of crystal structure from melt structure is also discussed. The melt phase separation of Ab12An36Di52, occurred in the high-temperature melt state, is studied, which reveals a very important immiscible feature in magmatic process. The types and relative contents of the different structure units correlative to temperature are discussed by Gaussian deconvolution of the high-frequencies spectrum region.
Two silicate glass samples at basaltic composition region, which are near the cotectic-line in Ab-An-Di phase diagram, were studied by high-temperature Raman spectroscopy using pulsed semiconductor laser and time-resolved detection technique from 298 K to 1 673 K. Temperature-dependent characteristic spectra and phase transition of glass, crystal and melt were observed. It is obvious that there exist some differences between the structure of glass and melt. The heredity of crystal structure from melt structure is also discussed. The melt phase separation of Ab12An36Di52, occurred in the high-temperature melt state, is studied, which reveals a very important immiscible feature in magmatic process. The types and relative contents of the different structure units correlative to temperature are discussed by Gaussian deconvolution of the high-frequencies spectrum region.
2004, 29(1): 45-49.
Abstract:
The studied diamonds come from the Yuanjiang River in Hunan Province, China. The diamonds were etched strongly, the etched lines and etched dislocation channels can be seen on the surface of diamond. The most commons are two sets lines, up to four sets occasionally. The line parallels each other in the same set, but across between two sets. Rows etched dislocation channels that represent zones of weakness in the crystal structure distribute along main deformed faces. Studies on the chosen polished slab specimens for micro-characters by gem microscope and polarizering microscope, cathodoluminescence (CL) show that the parallel extinctions caused by the main plastic deformation planes are clear under crossed polarizers, with two sets of parallel extinctions intersecting, three sets forming ring, four sets forming a strain phantom. The brown bands are closely related to the parallel extinctions; the brown bands are surely accompanied by the parallel extinctions, but the parallel extinctions do not guarantee to be accompanied by the brown bands. TEM shows both screw and knife dislocation can be seen and dislocation tangle is very clear; the dislocation density is uneven distribution: the density in tangle belt is clearly higher than that in the zone between two belts. The plastic deformation occurred after the growth stage of diamond.
The studied diamonds come from the Yuanjiang River in Hunan Province, China. The diamonds were etched strongly, the etched lines and etched dislocation channels can be seen on the surface of diamond. The most commons are two sets lines, up to four sets occasionally. The line parallels each other in the same set, but across between two sets. Rows etched dislocation channels that represent zones of weakness in the crystal structure distribute along main deformed faces. Studies on the chosen polished slab specimens for micro-characters by gem microscope and polarizering microscope, cathodoluminescence (CL) show that the parallel extinctions caused by the main plastic deformation planes are clear under crossed polarizers, with two sets of parallel extinctions intersecting, three sets forming ring, four sets forming a strain phantom. The brown bands are closely related to the parallel extinctions; the brown bands are surely accompanied by the parallel extinctions, but the parallel extinctions do not guarantee to be accompanied by the brown bands. TEM shows both screw and knife dislocation can be seen and dislocation tangle is very clear; the dislocation density is uneven distribution: the density in tangle belt is clearly higher than that in the zone between two belts. The plastic deformation occurred after the growth stage of diamond.
2004, 29(1): 50-54.
Abstract:
Sol-gel synthesis technique (SST) has been used to prepare SrAl2O4∶Eu2+, Dy3+. The XRD shows that the production prepared at 1 050 ℃ is pure-phase SrAl2O4∶Eu2+, Dy3+, and the phase will not change subjected to the temperature of 1 150 ℃-1 400 ℃. Effects of such factors as the temperature in the sintering process, different proportions of Eu/Sr, different additions of boracic acid, different proportions of Eu/Dy and different proportions of Al/Sr on the relative luminescent height have been studied. The research shows that under the condition of taking hydrogen as reductant, taking 1 200 ℃ as sintering temperature, keeping constant temperature for 2 hours and naturally lowering the temperature, high-quality phosphor products can be produced.
Sol-gel synthesis technique (SST) has been used to prepare SrAl2O4∶Eu2+, Dy3+. The XRD shows that the production prepared at 1 050 ℃ is pure-phase SrAl2O4∶Eu2+, Dy3+, and the phase will not change subjected to the temperature of 1 150 ℃-1 400 ℃. Effects of such factors as the temperature in the sintering process, different proportions of Eu/Sr, different additions of boracic acid, different proportions of Eu/Dy and different proportions of Al/Sr on the relative luminescent height have been studied. The research shows that under the condition of taking hydrogen as reductant, taking 1 200 ℃ as sintering temperature, keeping constant temperature for 2 hours and naturally lowering the temperature, high-quality phosphor products can be produced.
2004, 29(1): 55-58.
Abstract:
Natural and surfactant-modified geomaterials(such as zeolite, bentonite, dacite and rhyolite) were used to remove chlorohydrocarbons from wastewater in this paper.The results show that surfactant(HDTMA-Br)can enhance the removal of chlorohydrocarbons by geomaterials, of which the modified bentonite shows the highest degree of removal of dichloromethane, trichloromethane, tetrachloromethane, trichloroethylene, tetrachloroethylene, and chlorobenzene at 9.1, 18.9, 43.0, 20.0, 32.4 and 30.3μg·g-1, respectively.A good linear correlation exists between removal of chlorohydrocarbons and Koc(which refers to the distribution coefficients of organic substances between the organic carbon of sediment and water).
Natural and surfactant-modified geomaterials(such as zeolite, bentonite, dacite and rhyolite) were used to remove chlorohydrocarbons from wastewater in this paper.The results show that surfactant(HDTMA-Br)can enhance the removal of chlorohydrocarbons by geomaterials, of which the modified bentonite shows the highest degree of removal of dichloromethane, trichloromethane, tetrachloromethane, trichloroethylene, tetrachloroethylene, and chlorobenzene at 9.1, 18.9, 43.0, 20.0, 32.4 and 30.3μg·g-1, respectively.A good linear correlation exists between removal of chlorohydrocarbons and Koc(which refers to the distribution coefficients of organic substances between the organic carbon of sediment and water).
2004, 29(1): 59-64.
Abstract:
After sulfuric acid or hydrochloric acid leaching to remove iron from K-feldspar powders, the filtrate wastewater contains free acid and abundant useful metal ions such as iron. The leaching proportion of iron from K-feldspar powders is 88.3% after treated by the used sulfuric acid. With a purity of 94.1% and 74% respectively, voltaite crystal and solid FeCl3 have been produced by crystallizing in a lower temperature following the vaporization of the wastewater, with 70% iron and 96.5% potassium recovered. No need of high temperature and pressure, and with high efficiency, low energy loss and less pollution, this process proves its effectiveness. The strong acidity, Fe2+ and rather lower concentration of alkalis ions are responsible for voltaite, not jarosite, crystallizing from the acidic iron-bearing water.
After sulfuric acid or hydrochloric acid leaching to remove iron from K-feldspar powders, the filtrate wastewater contains free acid and abundant useful metal ions such as iron. The leaching proportion of iron from K-feldspar powders is 88.3% after treated by the used sulfuric acid. With a purity of 94.1% and 74% respectively, voltaite crystal and solid FeCl3 have been produced by crystallizing in a lower temperature following the vaporization of the wastewater, with 70% iron and 96.5% potassium recovered. No need of high temperature and pressure, and with high efficiency, low energy loss and less pollution, this process proves its effectiveness. The strong acidity, Fe2+ and rather lower concentration of alkalis ions are responsible for voltaite, not jarosite, crystallizing from the acidic iron-bearing water.
2004, 29(1): 65-68.
Abstract:
The Fe3O4-polyaniline(Fe3O4-PANI)nano-composites are synthesized via an in-situ polymerization of aniline monomer in SDBS-HCl aqueous solutions which contain well-dispersed Fe3O4nanoparticles, SDBS serving as surfactant and dispersant. The composites are characterized by means of XRD, TEM, FT-IR, et al. The results show that competing doping behavior happened between SDBS and HCl during the process of synthesis. The component of the composite is Fe3O4-PANI-DBSA. Fe3O4particlesin it are almost spherical with average size of 13 nm and dispersed in the base of PANI regularly. These composites possess good electrical conductivity and magnetization. With the content of Fe3O4increased from 7.79% to 35.34%, the conductivity of these composites gradually decreases from 1.71 S/m to 0.41 S/m, meanwhile the saturated magnetization(σs)increases from 6.14 A· m2/kg to 18.11 A·m2/kg, and the coercive force(Hc)is within the range of 0.52 A/m-0.73 A/m.
The Fe3O4-polyaniline(Fe3O4-PANI)nano-composites are synthesized via an in-situ polymerization of aniline monomer in SDBS-HCl aqueous solutions which contain well-dispersed Fe3O4nanoparticles, SDBS serving as surfactant and dispersant. The composites are characterized by means of XRD, TEM, FT-IR, et al. The results show that competing doping behavior happened between SDBS and HCl during the process of synthesis. The component of the composite is Fe3O4-PANI-DBSA. Fe3O4particlesin it are almost spherical with average size of 13 nm and dispersed in the base of PANI regularly. These composites possess good electrical conductivity and magnetization. With the content of Fe3O4increased from 7.79% to 35.34%, the conductivity of these composites gradually decreases from 1.71 S/m to 0.41 S/m, meanwhile the saturated magnetization(σs)increases from 6.14 A· m2/kg to 18.11 A·m2/kg, and the coercive force(Hc)is within the range of 0.52 A/m-0.73 A/m.
2004, 29(1): 69-76.
Abstract:
A regional unconformity-S6′ is distinguished in Tertiary filling sequence of Dongying depression by interpretation of 3D seismic profiles. This sequence boundary lies on the bottom of the 3rd Member, Shahejie Formation and can be traced and contrasted in the whole basin area.Analysis on stratigraphic thickness and tectonic stress field of the basin reveals that S6′ boundary divided the Tertiary synrifting stage into two episodes controlled by different tectonic stress fields, that is, the first episode of basin development and the second episode of basin development. The former was controlled by N-S trending extensional tectonic stress field, forming half grabens bounded by Chennan fault and Shicun fault; while the latter was controlled by NW-SE trending extensional tectonic stress field, forming half graben bounded by NE trending fault system. S6′ boundary is a regional unconformity and can be found and traced in Bohai gulf basin and many other basins in East China. The boundary occurred in late Middle Eocene, which was consistent with the time of a great reorganization of global plate tectonics during Cenozoic. Thus identification of S6′ boundary may provide new information for dynamic setting of formation and evolution of Cenozoic basins in East China.
A regional unconformity-S6′ is distinguished in Tertiary filling sequence of Dongying depression by interpretation of 3D seismic profiles. This sequence boundary lies on the bottom of the 3rd Member, Shahejie Formation and can be traced and contrasted in the whole basin area.Analysis on stratigraphic thickness and tectonic stress field of the basin reveals that S6′ boundary divided the Tertiary synrifting stage into two episodes controlled by different tectonic stress fields, that is, the first episode of basin development and the second episode of basin development. The former was controlled by N-S trending extensional tectonic stress field, forming half grabens bounded by Chennan fault and Shicun fault; while the latter was controlled by NW-SE trending extensional tectonic stress field, forming half graben bounded by NE trending fault system. S6′ boundary is a regional unconformity and can be found and traced in Bohai gulf basin and many other basins in East China. The boundary occurred in late Middle Eocene, which was consistent with the time of a great reorganization of global plate tectonics during Cenozoic. Thus identification of S6′ boundary may provide new information for dynamic setting of formation and evolution of Cenozoic basins in East China.
2004, 29(1): 77-84.
Abstract:
After the Permo-Carboniferous source rocks formed, they have gone through complicated tectonic-burial history in Wuqing depression, and multiple hydrocarbon-generation evolution have taken place. After detailed research on tectonic-burial history, combined with the fission tracks testing and fluid inclusion analyses, using the EASY% Ro numerical simulation, the paper reveals the evolution process, the tectonic episodes and the strength of hydrocarbon-generation of Permo-Carboniferous source rocks. It comes to a conclusion that two hydrocarbon-generation processes have taken place since the Permo-Carboniferous formation, and draws an important conclusion that more hydrocarbon-generation of the Permo-Carboniferous source rocks took place in late Cenozoic. Combined with the measuring map of hydrocarbon regenerated amount & maturation of organic matter, we quanti-tatively evaluated the hydrocarbon-generation strength of Permo-Carboniferous source rocks in different episodes. Finally the paper brings forward that Wuqing depression is an advantageous zone for the exploration of Permo-Carboniferous oil & gas in North China.
After the Permo-Carboniferous source rocks formed, they have gone through complicated tectonic-burial history in Wuqing depression, and multiple hydrocarbon-generation evolution have taken place. After detailed research on tectonic-burial history, combined with the fission tracks testing and fluid inclusion analyses, using the EASY% Ro numerical simulation, the paper reveals the evolution process, the tectonic episodes and the strength of hydrocarbon-generation of Permo-Carboniferous source rocks. It comes to a conclusion that two hydrocarbon-generation processes have taken place since the Permo-Carboniferous formation, and draws an important conclusion that more hydrocarbon-generation of the Permo-Carboniferous source rocks took place in late Cenozoic. Combined with the measuring map of hydrocarbon regenerated amount & maturation of organic matter, we quanti-tatively evaluated the hydrocarbon-generation strength of Permo-Carboniferous source rocks in different episodes. Finally the paper brings forward that Wuqing depression is an advantageous zone for the exploration of Permo-Carboniferous oil & gas in North China.
2004, 29(1): 85-92.
Abstract:
Chlorine is the most present element in coal. Content and distribution of chlorine in coal affect the use and processing of coal. Chlorine is a harmful element and may cause some technological and environmental problems during coal combustion. In this paper, the distribution, modes of occurrence and accumulation factors of chlorine in workable coal seams are studied. On the basis of analysis on the contents of chlorine in main workable coal seams from Jining coal field, the content of chlorine in study coal seams is not more than 0.5%, and it is classified as low chlorine coal. And the content and distribution of chlorine in coal are mainly related with spatial distribution and geographic location of coal seams, plants-formation coal, sedimentary environments and underground water activity. Modes of occurrence of chlorine in coal have been studied according to analysis on the relationship between chlorine and organic maceral, and ash yield. The results indicate that most of chlorine in coals has significant negative correlation with ash yield, and positive correlation with the virtrinite concentrations. It shows that the dominant part of chlorine in coal probably occurs as organic complexes.
Chlorine is the most present element in coal. Content and distribution of chlorine in coal affect the use and processing of coal. Chlorine is a harmful element and may cause some technological and environmental problems during coal combustion. In this paper, the distribution, modes of occurrence and accumulation factors of chlorine in workable coal seams are studied. On the basis of analysis on the contents of chlorine in main workable coal seams from Jining coal field, the content of chlorine in study coal seams is not more than 0.5%, and it is classified as low chlorine coal. And the content and distribution of chlorine in coal are mainly related with spatial distribution and geographic location of coal seams, plants-formation coal, sedimentary environments and underground water activity. Modes of occurrence of chlorine in coal have been studied according to analysis on the relationship between chlorine and organic maceral, and ash yield. The results indicate that most of chlorine in coals has significant negative correlation with ash yield, and positive correlation with the virtrinite concentrations. It shows that the dominant part of chlorine in coal probably occurs as organic complexes.
2004, 29(1): 93-95.
Abstract:
Tectonic stress action is one of the few effective over-pressuring mechanisms in many existing over-pressuring mechanisms. Therefore, a vertical three-dimensional tectonic stress section passing Kala 2 gas pool is simulated. The results show that there is about 10 MPa stress concentration at Kala 2 reservoir structural part, and that there is about 50 MPa that is caused by tectonic stress action in the overpressure of Kala 2 gas pool, and the rest by other over-pressuring mechanisms. This research has significance for reasonably assessing and developing gas pool.
Tectonic stress action is one of the few effective over-pressuring mechanisms in many existing over-pressuring mechanisms. Therefore, a vertical three-dimensional tectonic stress section passing Kala 2 gas pool is simulated. The results show that there is about 10 MPa stress concentration at Kala 2 reservoir structural part, and that there is about 50 MPa that is caused by tectonic stress action in the overpressure of Kala 2 gas pool, and the rest by other over-pressuring mechanisms. This research has significance for reasonably assessing and developing gas pool.
2004, 29(1): 96-102.
Abstract:
Songnen basin is located in the center of the northeast China. It is one of the main large-scale groundwater basin which is very abundant in groundwater resources in China, but the situation of groundwater there is complex: the original groundwater quality is not very good and the pollution due to human activities is relatively severe. Based on groundwater quality data monitored by water conservancy and geological department for many years, in-depth study on the formation mechanics and regional distribution laws of primary harmful components and man-made pollutant in groundwater is conducted. Furthermore, the perennial change laws of groundwater quality in the basin because of human activities are analyzed in the paper. The results show that the primary harmful components would be concentrated under the following conditions: the geological structure is enclosed, the environment of strong reducing/alkalescent/full of organic matter in groundwater and groundwater seepage velocity is slow. The main reason for change tendency of groundwater quality is the human activities in recent years. The paper gives some advice on amelioration and preservation of groundwater quality such as enhancing regional groundwater circulation and exchange function, fighting against environment pollution, treating or refreshing the polluted well and utilizing artificial recharge with clean water of Songhua River.
Songnen basin is located in the center of the northeast China. It is one of the main large-scale groundwater basin which is very abundant in groundwater resources in China, but the situation of groundwater there is complex: the original groundwater quality is not very good and the pollution due to human activities is relatively severe. Based on groundwater quality data monitored by water conservancy and geological department for many years, in-depth study on the formation mechanics and regional distribution laws of primary harmful components and man-made pollutant in groundwater is conducted. Furthermore, the perennial change laws of groundwater quality in the basin because of human activities are analyzed in the paper. The results show that the primary harmful components would be concentrated under the following conditions: the geological structure is enclosed, the environment of strong reducing/alkalescent/full of organic matter in groundwater and groundwater seepage velocity is slow. The main reason for change tendency of groundwater quality is the human activities in recent years. The paper gives some advice on amelioration and preservation of groundwater quality such as enhancing regional groundwater circulation and exchange function, fighting against environment pollution, treating or refreshing the polluted well and utilizing artificial recharge with clean water of Songhua River.
2004, 29(1): 103-108.
Abstract:
Qulong porphyry copper (molybdenum) deposit, which is located in the arc-basin transform place between the magma arc of eastern Gangdise and Riduo basin, controlled by basin-controlled, rock-controlled structure in basin edge, and formed in instantaneous transition environment of transform from convergent to extension, is the most potential superlarge deposit in ore-finding and its finding is the important breakthrough in the exploration process of porphyry deposit in eastern belt of Gangdise Mountain. The ore fluid of Qulong porphyry copper (molybdenum) deposit is composed of saturation and supersaturation brine-steam boiling fluids; its distribution characteristics of wall rock alteration include centering by porphyry, surfacing, and annular zone; it has undergone mineralization of 3 periods including 5 phases. It is found that the copper mineralization correlates with anhydrition and sericitization. This paper also probes into some key science issues which call for further studies and attention.
Qulong porphyry copper (molybdenum) deposit, which is located in the arc-basin transform place between the magma arc of eastern Gangdise and Riduo basin, controlled by basin-controlled, rock-controlled structure in basin edge, and formed in instantaneous transition environment of transform from convergent to extension, is the most potential superlarge deposit in ore-finding and its finding is the important breakthrough in the exploration process of porphyry deposit in eastern belt of Gangdise Mountain. The ore fluid of Qulong porphyry copper (molybdenum) deposit is composed of saturation and supersaturation brine-steam boiling fluids; its distribution characteristics of wall rock alteration include centering by porphyry, surfacing, and annular zone; it has undergone mineralization of 3 periods including 5 phases. It is found that the copper mineralization correlates with anhydrition and sericitization. This paper also probes into some key science issues which call for further studies and attention.
2004, 29(1): 109-118.
Abstract:
Geochemical and geophysical anomalies are originated from geological processes. These processes involve a great deal of complexity temporally and spatially. It is critical to improve the current anomaly extraction methods from the standpoint of the association of geophysical and geochemical anomalies for mineral exploration. The fractal singular-value-decomposition (MSVD) in GIS environment developed in this study is demonstrated superb in extracting linear and circular geophysical and geochemical anomalies as well as the detailed structural and textural information from 2D geochemical and geophysical maps. The MSVD method constructs a self-contained orthogonal basis using the outer product of left and right eigenvector matrixes decomposed from 2D geochemical or geophysical maps. A power-law relationship based on fractal theory has been suggested to associate the spectrum density and spectrum radius (or spectrum scale) defined in the paper. Multiple power-law relationships observed between the spectrum density and spectrum radius can help to group singular values and their corresponding eigenvectors. Each of these groups can be used to reconstruct the geophysical and geochemical maps to reflect decomposed components. The component reconstructed with relative large singular values may correspond to background and those obtained with relatively small singular values may represent anomalies. This method has been demonstrated using datasets from Nova Scotia, Canada. The results obtained for As and other elements from lake sediment samples, gravity anomalies and airborne magnetic anomalies have shown that the power-law relationship might exist between spectrum density and spectrum radius. Several different exponents are observed from the datasets which can be based to separate the anomalies from background.
Geochemical and geophysical anomalies are originated from geological processes. These processes involve a great deal of complexity temporally and spatially. It is critical to improve the current anomaly extraction methods from the standpoint of the association of geophysical and geochemical anomalies for mineral exploration. The fractal singular-value-decomposition (MSVD) in GIS environment developed in this study is demonstrated superb in extracting linear and circular geophysical and geochemical anomalies as well as the detailed structural and textural information from 2D geochemical and geophysical maps. The MSVD method constructs a self-contained orthogonal basis using the outer product of left and right eigenvector matrixes decomposed from 2D geochemical or geophysical maps. A power-law relationship based on fractal theory has been suggested to associate the spectrum density and spectrum radius (or spectrum scale) defined in the paper. Multiple power-law relationships observed between the spectrum density and spectrum radius can help to group singular values and their corresponding eigenvectors. Each of these groups can be used to reconstruct the geophysical and geochemical maps to reflect decomposed components. The component reconstructed with relative large singular values may correspond to background and those obtained with relatively small singular values may represent anomalies. This method has been demonstrated using datasets from Nova Scotia, Canada. The results obtained for As and other elements from lake sediment samples, gravity anomalies and airborne magnetic anomalies have shown that the power-law relationship might exist between spectrum density and spectrum radius. Several different exponents are observed from the datasets which can be based to separate the anomalies from background.
2004, 29(1): 119-126.
Abstract:
The process of contamination identification at Dexing copper mine based on the spectral feature of pollutions such as mine offal, waste water and vegetation and so on are investigated using spectral identification tree technique for Hyperion data. The spectra of various surface materials at mine are analyzed at first. And then the different contaminations, the Fe-bearing minerals including Fe3+ and mixture of Fe2+ and Fe3+ based on the spectral absorption feature of 700 nm, 1 000 nm and 2 200 nm, the pollution water and their relative pH based on the spectral feature of 600 nm, the vegetation contamination caused by mine offal and pollution water based on the maximum absorption of spectral depth between 580 nm-750 nm, are identified and extracted using Hyperion data. The spectral database of mining pollution is proposed. A good idea of identifying mining pollution quickly and directly is put forward using hyperspectral imaging technique. The project can be very practical in terms of technical support for inspecting and surveying, managing and planning, remedial action of mine environment.
The process of contamination identification at Dexing copper mine based on the spectral feature of pollutions such as mine offal, waste water and vegetation and so on are investigated using spectral identification tree technique for Hyperion data. The spectra of various surface materials at mine are analyzed at first. And then the different contaminations, the Fe-bearing minerals including Fe3+ and mixture of Fe2+ and Fe3+ based on the spectral absorption feature of 700 nm, 1 000 nm and 2 200 nm, the pollution water and their relative pH based on the spectral feature of 600 nm, the vegetation contamination caused by mine offal and pollution water based on the maximum absorption of spectral depth between 580 nm-750 nm, are identified and extracted using Hyperion data. The spectral database of mining pollution is proposed. A good idea of identifying mining pollution quickly and directly is put forward using hyperspectral imaging technique. The project can be very practical in terms of technical support for inspecting and surveying, managing and planning, remedial action of mine environment.
