2013 Vol. 19, No. 3

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AN OVERVIEW ON EARTHQUAKE-INDUCED LANDSLIDE RESEARCH
ZHANG Duo, WU Zhong-hai, LI Jia-cun, JIANG Yao
2013, 19(3): 225-241.
Abstract (364) HTML (154) PDF (1138KB)(29)
Abstract:
Earthquake induced landslide is one of the most common geological disasters in great earthquake of continent internal mountain. It not only has large amount and great scale, but also causes serious damage for human activities. So, it is extraordinarily significant to analysis the earthquake induced landslide for evaluating the seismic risk. This paper scientifically concludes the research status of landslide at domestic and overseas, based on the law of earthquake induced landslide development and dynamics mechanism. Then, it summarizes the 3S technique specific application to the landslides.
OVERVIEW OF QUATERNARY DATING METHODS AND THEIR APPLICATION IN NEOTECTONICS AND ACTIVE TECTONICS RESEARCH
TIAN Ting-ting, WU Zhong-hai, ZHANG Ke-qi, ZHANG Xu-jiao
2013, 19(3): 242-266.
Abstract (330) HTML (63) PDF (1824KB)(59)
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The quantitative or semi-quantitative research of neotectonics and active tectonics largely relies on the establishment of stratigraphic sequence and the time scale, how to obtain relatively precise the stratigraphic ages and the age of occurrence of geological events is the key factor to determine the neotectonics and active tectonics degree of quantitative research. Currently, about 27 kinds of dating techniques can be applied to the dating of sediments and the deformation measurement of the late Cenozoic, these technical methods can be divided into numerical (absolute) dating, relative dating method and correction dating method. Numerical dating can get a relatively clear absolute age value, so it is commonly used, but is limited by test material or object, therefore it is necessarily in need with relative dating or correction dating method. The application scope of relative dating is widespread, but the lack of adequate accuracy, therefore it needs specific standard to compare. Correction dating is only partly applicable and its applicability depends on the approval of the known geological events, such as volcanic eruptions or pole reversals. All the dating method has its specific dating conditions and scope of application, and may be influenced by various factors leading to errors, such as in the process of numerical dating some non analytical errors may occur. So the reliability evaluation of age results in the study of the Quaternary dating in the neotectonics and active tectonics, needs the synthesis of sediment topography-formation relative temporal sequence, comparation of different dating methods, or the sequential consistency of the same way on the formation, etc. In recent years, the continuous improvement of existing methods and development of experimental methods makes that the precision and quantitative research degree of the neotectonics and active tectonics is improved greatly, especially common dating methods such as the 14C, OSL, U series, cosmogenic nuclides (10Be, 36Cl and 26Al, etc.) and thermochronological dating provide the important means and basis of chronology for the quantitative research of neotectonics and active tectonics. In addition, such as the degrees of soil development, rock weathering and topographical reforming, the development of relative dating also provide a lot of necessary, assistant age restriction for the neotectonics deformation and active tectonics research.
ACORITE U-Pb CHRONOLOGY CHARACTERISTICS AND ITS GEOLOGICAL SIGNIFICANCE OF DUCTILE SHEAR DEFORMABLE BELT IN SOUTHEASTERN HAINAN ISLAND, CHINA
LI Sun-xiong, WEI Chang-xin, WANG Yan-hua, CHEN Fang-ying
2013, 19(3): 267-274.
Abstract (183) HTML (88) PDF (1593KB)(10)
Abstract:
The ductile shear belt exposures in Mangsan Reservoir-Diaoluoshan Tree Farm-Xinglong area successively with its strike being north-east. The lithology is tectonic gneiss and granite of mylonitization, and main minerals are composed of feldspar, quartz and biotite. The rock develops as "S-C" fabric, "δ" style gyral porphyroclast system, mica fish etc. The tectonic fabric indicates right handed shearing movement. According to mineral component and deforming feature, the deforming environment should be low amphibolite facies, which belongs to the product emplacing across the shear zone and transforming synchronously. This time we got 284.3±1.3 Ma and 265.9±1.3 Ma by laser ICP-MS for zircons from Mangsan Reservoir and Diaoluoshan Tree Farm. The founding of ductile shear belt and its geologic age plays an important role in the intensive study of construction-magma function of Hainan Island.
MICROTECTONIC FEATURES AND EVOLUTION OF THE YUSHIGOU PERIDOTITE ROCK FROM THE QILIANSHAN MOUNTAIN
YANG Yan, YANG Bo, ZHANG Hong-yuan
2013, 19(3): 275-286.
Abstract (106) HTML (324) PDF (2069KB)(8)
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As a main component of upper mantle, peridotite affects the rheological behavior of the upper mantle. The microstructures contain records of tectonic events experienced during the development process of the specimen. Rheological parameters, such as temperature, confining pressure, factors of water and strain rate, are defined according to microtectonic observations, EBSD data and TEM results. Deformation mechanisms, deformation history of the Yushigou rock samples and geotectonic environment are summarized. Problems of petrogenesis and evolution history of the Yushigou peridotite body are finally concluded as:Ⅰ, the evolution stage in the upper mantle, which is indicated by the A-type original fabric of olivine. The fabric of olivine lattice-preferred orientation (LPO) is determined by electron backscatter diffraction (EBSD) analysis. Our peridotite sample shows some upper mantle features, such as high temperature (>1200℃), low stress ( < 350 MPa), low strain rate and low water content environmental conditions. Ⅱ, the ductile-brittle deformation stage, showing D-type fabric which superimposed and transformed the A-type original fabric. Dynamic recovery is the main controlling factor for olivine deformation. Sub-grains, extinction bands and kink bands are generally observed by polarized-light microscopy, and are also shown as dislocation rows in the transmission electron microscopy (TEM) graphs. Brittle microcrack fabric including micro fractures with different dynamic nature is also analyzed as two groups of conjugate shear ruptures and another group of tension fractures. One same stage of paleostress field is shown by both microcrack and the ductile dynamic recovery phenomena.
A PRELIMINARY DISCUSSION ON FEASIBILITY USING THERMALLY TRANSFERRED OPTICALLY STIMULATED LUMINESCENCE (TT-OSL) METHOD TO DATE THE FINE-GRAIN QUARTZ EXTRACTED FROM GANZI LOESS
ZHANG Ke-qi
2013, 19(3): 287-294.
Abstract (204) HTML (83) PDF (1371KB)(9)
Abstract:
This paper attempts to date the loess from Ganzi area, Sichuan province, using a new method-TT-OSL protocol for OSL dating. A preliminary experimental study was conducted loess from the Ganzi-A section. Testing result showed that the naturally recuperated OSL signal intensity increases with depth of stratum, being obvious accumulation. A 'replacement plot' analysis was applied to test the reliability of the TT-OSL protocol and showed a nice result. The De values of 3 samples were measured by SMAR and TT-OSL protocols, respectively, and ages were calculated. The comparison between De-TTOSL and De-SMAR show the former was greater than that of the latter, and comparison between the ages is as well. However the ages of TT-OSL method is less than the expected value from magnetostratigraphy. Based on the results, the TT-OSL method was applied to fine-grained quartz extracted from the Ganzi loess. But the reliability of results from TT-OSL dating needed to be tested and verified by more independent ages.
APPLICATION OF GIS IN LANDSLIDE STABILITY EVALUATION: A CASE STUDY FOR ERMANSHAN LANDSLIDE
TAN Chun-hong, ZHU Zhi-ming, ZHOU Kai-rui, BIAN Jing-sheng, WEI Yuan, ZOU Zu-yin, ZHANG Yun-qi
2013, 19(3): 295-303.
Abstract (120) HTML (85) PDF (1762KB)(13)
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In this paper, the method of theoretical knowledge, field surveys and laboratory experiments were used to analyze the environmental conditions, development characteristics and mechanism of the Ermanshan landslide in Hanyuan County, selecting the characters of landslide, geological structure, elevation, aspect, slope, earthquake, rainfall and other factors as analysis variables. We combine GIS with fuzzy mathematical evaluation method, develop the landslide stability evaluation plug-in, and then divide the risk regionalization of study area, in order to avoid occurrence of geological hazards in the area, reduce casualties and property losses. The results show that the landslide areas are mainly concentrated on the elevation at about 1600 m and 30° to 50° slope area. With the increase of height and slope, the possibility of landslides is raised.
APPLICATION OF 90°-PHASE SEISMIC DATA IN PREDICTION OF SANDSTONE
PAN Wei-hong, LIU Hao, ZHANG Liang, ZHANG Shuai, ZHAO Chun-chen
2013, 19(3): 304-314.
Abstract (179) HTML (101) PDF (2197KB)(25)
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Taking the 2nd Member of Shahejie Formation in the Yellow River Mouth sag as an example, geological models were built depending on the 90° phasing of seismic data and the geologic setting. The modeling synthesis records from 0°-phase to 90°-phase were used to make the geological models more precise. Then according to the attributive character obtained from the 90°-phase of seismic data, seismic attributions extraction and formation slices could be used to predict the distribution of the sandstone. The results indicate that the geological models can be directly perceived through the 90°-phase seismic data, and at the same time the trough of waves can not only correspond to the sand body but also show the outline of the sand belt which is spreading in the seismic modeling synthesis of 90°phasing. What's more, the ichnography from the seismic attribution extraction about the character of trough amplitude can clearly show the contour profiles and boundaries of the sandstone.
A FIBRE OPTIC EXTRINSIC FABRY-PEROT INTERFEROMETER WITH TEMPERATURE COMPENSATION FOR FAULT MEASUREMENT
PENG Hua, MA Xiu-min, WANG Zhen, CUI Liu-zhu, JIANG Yi
2013, 19(3): 315-324.
Abstract (206) HTML (70) PDF (1697KB)(7)
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Fibre optic EFPI sensor is usually very small in size while the fault size is relatively big, so it is not suitable to be installed at the fault for the fibre optic EFPI. As a result, fibre optic extrinsic Fabry-Perot interferometer for fault measurement, EFPI was present. EFPI structure is formed as two ceramic ferrule inserted into the ceramic casing from the ends. Two ceramic ferrule are respectively fixed on the two metal inner tube, which are inserted into the metal outer tube form the two ends. O-type sealing rings are put at each end of the metal outer tube, so the EFPI displacement sensor is capable of waterproof and dustproof. In order to eliminate the influence of temperature on EFPI displacement sensor, two metal tubes with different thermal expansion coefficient material are chosen for temperature compensation in the structure. In the experiment, EFPI displacement sensor with 718.39 μm of the cavity length was measured in a continuous changing temperature situation. The results shows that temperature coefficient of displacement sensor has declined by 0.14 μm/℃ to -0.04 μm/℃ after temperature compensation, and showed a compensation.
CONTACT ALGORITHM OF 3D MECHANICAL FINITE ELEMENT MODELING FOR SEPARATION OF OVERBURDEN LAYERS AND ITS APPLICATION
WU Ze-dong, Xue Ai-min, Cao Ding-tao
2013, 19(3): 325-333.
Abstract (169) HTML (90) PDF (1828KB)(6)
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Based on the specialty of separation layer, this paper proposes a new contact algorithm with the adoption of massive parallel computation for the study of separation of overburden layers in coal mine production. We have done the real 3D mechanic simulation and get the potential location, shape and volume for separation of overburden layers. Meanwhile, the study takes the area of No.2 coal mine of Jining as an example, which proves the applicability and validity of this new algorithm.
COMPLEX FLAC3D THREE DIMENSIONAL GEOLOGICAL MODELING BASED ON MOVING LEAST SQUARES METHOD
LI Guo-qing, Wang Xin-qing, YIN Gai-mei
2013, 19(3): 334-342.
Abstract (166) HTML (77) PDF (1741KB)(6)
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FLAC3D is an excellent computer code for rock-soil mechanics numerical simulation, but it performs poor in modeling complex geological body. The features of modeling commands and *FLAC3D type file were elaborated, the space coordinate transformation and MLS interpolation method were introduced in detailed and a new modeling method was proposed and a computer aided modeling program was developed. The input of the program is just original data and does not need the aid of other commercial software. Through coordinate transformation and MLS interpolation, our method can quickly build complex geological model and is convenient to set material parameters and apply the stress boundary conditions, thereby can effectively improve the work efficiency.
A NEW METHOD FOR WATER SOLUBLE GAS RECOGNITION BASED ON COMPREHENSIVE LOGGING: TAKING GUSHI SAG AS AN EXAMPLE
ZHANG Lin, LIU Jian-chao, WANG Xing-yun, BAI Jian-feng
2013, 19(3): 343-350.
Abstract (261) HTML (176) PDF (1863KB)(15)
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Based on the deep analysis and research on the difficulties of identifying water-soluble methane gas reservoir in Tertiary Zhangjiapo Formation sandstone reservoir in Weihe Basin, combined gas logging data, the article was written to solve the difficulties of identification and interpretation about gas-and water-bearing layers, and to provide better services for exploitation of water-soluble gas unconventional new energy exploration. The authors established a set of standards such as porosity overlapping contrast method, porosity difference and ratio (porosity parameter method), and contrastive analysis between compensation neutron and compensated density curves which are suitable in the study area and the TNIS imaging logging to recognize integratedly gas-and water-bearing layers. The standards have been used in the twenty-eight sections in the study area. And compared with the practical production, the compliance rate was 90%, indicating application effect of this method was good. The method may provide reference and guidance for exploration and development of other water-soluble gas basin.