The Northern Qaidam Basin is located at the northeastern part of the Qinghai-Tibetan Plateau. It contains very thick Cenozoic terrestrial clastic sediments, which records the formation of the northern Qaidam Basin due...The Northern Qaidam Basin is located at the northeastern part of the Qinghai-Tibetan Plateau. It contains very thick Cenozoic terrestrial clastic sediments, which records the formation of the northern Qaidam Basin due to compressional deformation during the Indo-Asian collision. In this paper, we used detrital apatite fission-track thermochronology, including 4 sandstones and 2 conglomerates samples from the Lulehe section, to reveal the Cenozoic evolution of the northern Qaidam Basin. Fission-track dating indicated the source region of the Lulehe section has experiencedimportant cooling and uplifting in the Late Cretaceous(at ~85.1 Ma and ~65 Ma) and the Eocene(~52 Ma), respectively. The AFT age distribution on the section suggested that the provenance of Lulehe section sediments were mainly derived from the south Qilian Shan(Qilian Mountains) and Altun Shan(Altun Mountains), and two significantly provenance changes may occur at 43.4-46.1 Ma and ~37.8 Ma, respectively. The results may have strong constrains on the Cenozoic deformation and tectonic evolution of the northern Qaidam Basin and Qinghai-Tibet Plateau.展开更多
In a karst tunnel, fissures or cracks that are filled with weathered materials are a type of potential water outlet as they are easily triggered and converted into groundwater outlets under the influence of high groun...In a karst tunnel, fissures or cracks that are filled with weathered materials are a type of potential water outlet as they are easily triggered and converted into groundwater outlets under the influence of high groundwater pressure. A terrible water inrush caused by potential water outlets can seriously hinder the project construction. Potential water outlets and water sources that surrounding the tunnel must be detected before water inflow can be treated. This paper provides a successful case of the detection and treatment of water inflow in a karst tunnel and proposes a potential water outlet detection(PWOD) method in which heavy rainfall(>50 mm/d) is considered a trigger for a potential water outlet. The Daba tunnel located in Hunan province, China, has been constructed in a karst stratum where the rock mass has been weathered intensely by the influence of two faults. Heavy rain triggered some potential water outlets, causing a serious water inrush. The PWOD method was applied in this project for the treatment of water inflow, and six potential water outlets in total were identified through three heavy rains. Meanwhile, a geophysical prospecting technique was also used to detect water sources. The connections between water outlets and water sources were identified with a 3-D graphic that included all of them. According to the distribution of water outlets and water sources, the detection area was divided into three sections and separately treated by curtain grouting.展开更多
In this work, Jazan province （Saudi Arabia） was examined for its heavy metals content. Therefore, 15 street dust samples were collected, digested and analyzed in order to investigate the levels of selected heavy met...In this work, Jazan province （Saudi Arabia） was examined for its heavy metals content. Therefore, 15 street dust samples were collected, digested and analyzed in order to investigate the levels of selected heavy metals and propose the causes for the presence of these metals. All collected samples were digested using Leeds Public Analyst method. The concentrations of heavy metals （Fe, Cu, Mn, Zn, Cd, Co and Pb） were analyzed using atomic absorption spectroscopy. Six heavy metals （Fe, Cu, Mn, Zn, Co and Pb） were measured in all samples; the concentration of Cd was not detected in Jazan dust by atomic absorption spectroscopy. The heavy metals levels in Jazan street dust increase according to the following sequence： Fe 〉 Mn 〉 Zn 〉 Cu 〉 Pb 〉 Co. The correlation coefficients and enrichment factors relative to earth crust abundances of heavy metals were calculated in order to predict the possible sources in dust.展开更多
This research objective is to propose a co-valorization of powdered tuff, containing a slight amount of clay and dune sand, by mixing the two substances at different rates such as 0%, 5%, 15%, 25% and 35% of sand. The...This research objective is to propose a co-valorization of powdered tuff, containing a slight amount of clay and dune sand, by mixing the two substances at different rates such as 0%, 5%, 15%, 25% and 35% of sand. The adapted criteria formulas are those recommended by the technical Saharan road. The results of the proposed study showed that ＂tuff-sand＂ mixtures are denser with a lower optimum water content modified proctor, the fine rate decreases together with the plasticity index, whereas the bearing index （CBR： California bearing ratio test） increases. The intrinsic characteristics, cohesion and sensitivity of mixtures with respect to compactness are almost identical to those oftuffwithout addition. The optimal adapted sand incorporation rate is estimated at 25% at 96% of compactness. Under these conditions, the amount of fines decreases from 40% to an acceptable level of 25% and the plasticity index from 16.2 to 12. The compaction water content decreases by 36% and the CBR （bearing index） increases by 30% and the compressive strength and sensitivity, according to compactness, of the elaborated material are almost identical to those oftuffwithout addition.展开更多
A comprehensive study on geothermal history of the Turpan-HamiBasin by vitrinite reflectance, fluid inclusion geothermometry, apatite fission track and 40Ar-39Ar dating displays that the main effects influencing geote...A comprehensive study on geothermal history of the Turpan-HamiBasin by vitrinite reflectance, fluid inclusion geothermometry, apatite fission track and 40Ar-39Ar dating displays that the main effects influencing geotemperature distribution are burial depth of the basement, heat flow, magmatic activities, as well as tectonic movement, having a rugulation to be higher in the east and north, lower in the west and south, as well as higher in the past and lower at the present. The heat of the mantle source and the Indo-China tectonic thermal event have extremely influenced matura-tion of source rocks of the upper Lower Permian and the Middle and Upper Triassic in the lndo-China epoch. While, the geothermal gradient and the weak tectonic geothermal event of the Early Yanshan Movement provided necessary heat for the maturation of source rock in coal-bearing strata of the Middle and Lower Jurassic.展开更多
基金funded by the Natural Science Foundation of China (Grants No. 41501209 and 41571177)the Fundamental Research Funds for the Central Universities (862457, lzujbky-2016-22)
文摘The Northern Qaidam Basin is located at the northeastern part of the Qinghai-Tibetan Plateau. It contains very thick Cenozoic terrestrial clastic sediments, which records the formation of the northern Qaidam Basin due to compressional deformation during the Indo-Asian collision. In this paper, we used detrital apatite fission-track thermochronology, including 4 sandstones and 2 conglomerates samples from the Lulehe section, to reveal the Cenozoic evolution of the northern Qaidam Basin. Fission-track dating indicated the source region of the Lulehe section has experiencedimportant cooling and uplifting in the Late Cretaceous(at ~85.1 Ma and ~65 Ma) and the Eocene(~52 Ma), respectively. The AFT age distribution on the section suggested that the provenance of Lulehe section sediments were mainly derived from the south Qilian Shan(Qilian Mountains) and Altun Shan(Altun Mountains), and two significantly provenance changes may occur at 43.4-46.1 Ma and ~37.8 Ma, respectively. The results may have strong constrains on the Cenozoic deformation and tectonic evolution of the northern Qaidam Basin and Qinghai-Tibet Plateau.
基金supported by the National Key Research and Development Project (Grant No.2016YFC0801604)Natural Science Foundation of Shandong Province (Grant No.ZR2017MEE070)
文摘In a karst tunnel, fissures or cracks that are filled with weathered materials are a type of potential water outlet as they are easily triggered and converted into groundwater outlets under the influence of high groundwater pressure. A terrible water inrush caused by potential water outlets can seriously hinder the project construction. Potential water outlets and water sources that surrounding the tunnel must be detected before water inflow can be treated. This paper provides a successful case of the detection and treatment of water inflow in a karst tunnel and proposes a potential water outlet detection(PWOD) method in which heavy rainfall(>50 mm/d) is considered a trigger for a potential water outlet. The Daba tunnel located in Hunan province, China, has been constructed in a karst stratum where the rock mass has been weathered intensely by the influence of two faults. Heavy rain triggered some potential water outlets, causing a serious water inrush. The PWOD method was applied in this project for the treatment of water inflow, and six potential water outlets in total were identified through three heavy rains. Meanwhile, a geophysical prospecting technique was also used to detect water sources. The connections between water outlets and water sources were identified with a 3-D graphic that included all of them. According to the distribution of water outlets and water sources, the detection area was divided into three sections and separately treated by curtain grouting.
文摘In this work, Jazan province （Saudi Arabia） was examined for its heavy metals content. Therefore, 15 street dust samples were collected, digested and analyzed in order to investigate the levels of selected heavy metals and propose the causes for the presence of these metals. All collected samples were digested using Leeds Public Analyst method. The concentrations of heavy metals （Fe, Cu, Mn, Zn, Cd, Co and Pb） were analyzed using atomic absorption spectroscopy. Six heavy metals （Fe, Cu, Mn, Zn, Co and Pb） were measured in all samples; the concentration of Cd was not detected in Jazan dust by atomic absorption spectroscopy. The heavy metals levels in Jazan street dust increase according to the following sequence： Fe 〉 Mn 〉 Zn 〉 Cu 〉 Pb 〉 Co. The correlation coefficients and enrichment factors relative to earth crust abundances of heavy metals were calculated in order to predict the possible sources in dust.
文摘This research objective is to propose a co-valorization of powdered tuff, containing a slight amount of clay and dune sand, by mixing the two substances at different rates such as 0%, 5%, 15%, 25% and 35% of sand. The adapted criteria formulas are those recommended by the technical Saharan road. The results of the proposed study showed that ＂tuff-sand＂ mixtures are denser with a lower optimum water content modified proctor, the fine rate decreases together with the plasticity index, whereas the bearing index （CBR： California bearing ratio test） increases. The intrinsic characteristics, cohesion and sensitivity of mixtures with respect to compactness are almost identical to those oftuffwithout addition. The optimal adapted sand incorporation rate is estimated at 25% at 96% of compactness. Under these conditions, the amount of fines decreases from 40% to an acceptable level of 25% and the plasticity index from 16.2 to 12. The compaction water content decreases by 36% and the CBR （bearing index） increases by 30% and the compressive strength and sensitivity, according to compactness, of the elaborated material are almost identical to those oftuffwithout addition.
文摘A comprehensive study on geothermal history of the Turpan-HamiBasin by vitrinite reflectance, fluid inclusion geothermometry, apatite fission track and 40Ar-39Ar dating displays that the main effects influencing geotemperature distribution are burial depth of the basement, heat flow, magmatic activities, as well as tectonic movement, having a rugulation to be higher in the east and north, lower in the west and south, as well as higher in the past and lower at the present. The heat of the mantle source and the Indo-China tectonic thermal event have extremely influenced matura-tion of source rocks of the upper Lower Permian and the Middle and Upper Triassic in the lndo-China epoch. While, the geothermal gradient and the weak tectonic geothermal event of the Early Yanshan Movement provided necessary heat for the maturation of source rock in coal-bearing strata of the Middle and Lower Jurassic.
