Yu Z.H.,Ocean University of China |
Gao Y.H.,Shandong Institute of Geophysical and Geochemical Exploration |
Zhai S.K.,Ocean University of China |
Liu F.,Ocean University of China
Science China Earth Sciences | Year: 2012
A sediment core H9 collected from the middle of the Okinawa Trough was studied by sequential leaching to indentify the hydrothermal component from the various other components such as detrital, biogenic, and so on. The elements were partitioned into five fractions: exchangeable, bound to carbonates, bound to iron and manganese oxides, bound to organic matter, and residual. The contents of elements Al, Ti, K, Fe, Mn, Pb, Co, Cu, Ni, and V in each fraction were determined and their percentages were calculated. Residual fraction is a dominant speciation for most studied elements except for Mn and Pb in the core sediments. For the elements Al, Ti, and K, residual fraction accounts for more than 95% of the total metal concentration. The concentrations of all studied elements in the exchangeable fraction, carbonate fraction, and organic fraction are relatively low. The metal levels in the iron and manganese oxide fraction are relatively high and this fraction represents another prevalent speciation. Also in this fraction, the metal concentrations and percentages are higher in the core section above 80 cm than those below 80 cm. Especially for Mn and Pb, the fractions bound to iron and manganese oxides account for more than 50% of the total metal concentration for the upper 80 cm section. Hydrothermal components mainly occur in this fraction. And the downcore variations of metal contents and percentages reflect the variations of hydrothermal inputs to the sediments. The high metal levels in the upper core indicate the enhancing influence of hydrothermal activities around on the core H9 during its late stage of sedimentation. The accumulation rates of hydrothermally derived Fe, Mn, Pb, Co, Cu, Ni, and V were evaluated based on their concentrations in the iron and manganese oxide fractions in this study. The results show that the accumulation rate of hydrothermally derived Mn is similar to those obtained from the Mid-ocean Ridges and Lau Basin. However, hydrothermally derived Fe and Cu present a relatively lower level. © 2011 Science China Press and Springer-Verlag Berlin Heidelberg.
Yang L.,Shandong University of Science and Technology |
You C.-A.,Shandong University of Science and Technology |
Zhao Y.-H.,Shandong Institute of Geophysical and Geochemical Exploration |
Gou W.-L.,Shandong University of Science and Technology |
Liu Q.-N.,Shandong University of Science and Technology
Meitan Xuebao/Journal of the China Coal Society | Year: 2015
The U-steel yieldable support is used in the coal roadway, which is difficult to be supported, due to its characteristics of high retaining ability, contractible capacity and convenient application. However, its own limitations of high cost, poor stability and harsh compressive conditions are difficult to be overcome, which results in its limited application. In order to solve these problems, a grille-yieldable support is proposed, and its internal force characteristic and the mechanical response caused by the yielding under the load are investigated through mechanical calculation, experimental research and numerical simulation analysis in this paper. The results show that this grille-yieldable support has a reasonable structure and a satisfactory performance on bending resistance and torsion resistance. Besides, its stability and bearing capacity are improved to a large extent. During the yielding of the support, the internal force tends to be uniform while the yielding resistance is gradually added. Due to the simplex yielding condition, it is ease to guarantee the support yielding steadily so as to avoid a sudden failure caused by buckling instability. The grille-yieldable support has many advantages such as light weight, low cost, abundant material source and easy manufacturing. In addition, it is convenient to operate with the bolt-shotcrete support, therefore, the grille-yieldable support is a practical roadway supporting form which has a great application prospect. © 2015, China Coal Society. All right reserved.
Zhang K.,Chinese Academy of Geological Sciences |
Yan J.Y.,Chinese Academy of Geological Sciences |
Lu Q.T.,Chinese Academy of Geological Sciences |
Wei W.B.,Beijing University of Technology |
And 3 more authors.
Acta Petrologica Sinica | Year: 2014
In order to understand the deep structure of lithosphere more comprehensively and objectively in Nanjing (Ning)-Wuhu (Wu) and explore lithospheric thermal structure and crust, mantle status and other important scientific issues, and provide the basis for ore district mineralization and metallogenic regularity, we finish 6 MT profiles and discuss the "apparent three-dimensional" conductivity structure of crust-upper mantle through imaging studies. Find that a big low-resistivity layer exists in crust-upper mantle, and the layer is substantially continuous, but disconnects in Chaohu fold belt region. Combined with regional heat flow results, we believe that the lower crust-upper mantle is conductive, and "melt" or "aqueous shear fracture" may be existed, and the state of matter is likely to be hot and weak. In addition, we infer the location of upper mantle uplift and distribution range of the Yangtze River deep fault through the material and electrical properties, and we consider that the Yangtze River fault is not only exist, but also composes by a number of faults, and the faults is more complex and deep in the north.
Yang L.-Z.,Shandong Institute of Geological Survey |
Qu W.-L.,Qingdao Geo Engineering Exploration Institute |
Zhang Y.,Shandong Institute of Geophysical and Geochemical Exploration |
Liu C.-H.,Shandong Institute of Geological Survey
Acta Geoscientica Sinica | Year: 2013
Aimed at solving the geo-environmental problems such as land subsidence resulting from continuous falling of water table due to over-exploitation, the authors selected the area of deep groundwater in Dezhou City as the key study area and took water chemical composition and environmental isotopic information as the study targets to discuss origin and refreshing capacity of deep groundwater. The results show that deep groundwater in Dezhou was mainly derived from precipitation in the last glacial period characterized by cold climate. During its formation, it had the characteristics of leaching and was affected by evaporation and cation exchange action. Later, it was interfered by many times of seawater invasion. It was dominated by HCO3-Na type water characterized by high fluorine, high sodium, low calcium and alkalescence, together with low concentrations of hydrogen and oxygen isotopes and low tritium content. The deep groundwater in Dezhou is recycled slowly and its refreshing capability is weak.
Zhang K.,Chinese Academy of Geological Sciences |
Zhang K.,CAS Institute of Geology and Geophysics |
Wei W.,Beijing University of Technology |
Lu Q.,Chinese Academy of Geological Sciences |
And 2 more authors.
Exploration Geophysics | Year: 2016
To solve the problem of correction of magnetotelluric (MT) static shift, we quantise factors that influence geological environments and observation conditions and study MT static shift according to 3D MT numerical forward modelling and field tests with real data collection. We find that static shift distortions affect both the apparent resistivity and the impedance phase. The distortion results are also related to the frequency. On the basis of synthetic and real data analysis, we propose the concept of generalised static shift resistivity (GSSR) and a new method for correcting MT static shift. The approach is verified by studying 2D inversion models using synthetic and real data. © 2016 ASEG.