Utilizing the practical study on the continental basins,the authors divide the whole third-order sequence into four systems tracts, which are lowstand systems tract (LST), transgressive systems tract (TST), highstand systems tract (HST) and regressive systems tract (RST),named sequence type I. If LST is undeveloped in a thirdorder sequence, it forms the assemblages of TST, HST and RST，named sequence type II. LST occurred in the rapid declining period of lake level (base level). TST appeared with first lake flooding surface and maximum lake flooding surface. HST formed in the relative static high lakelevel period. RST formed in the gradual lake-level fall stage, and the supplying rate of sediments was more than the increasing rate of accommodation space at that time. Generally, LST consists of small scale progradational parasequence sets, vertically, the sedimentary environment is shallower, and river downcutting forms in the basin margin. TST consists of retrogradational parasequence sets, and the sedimentary environment becomes deeper from bottom to up. HST consists of aggradational parasequence sets, and the sedimentary environment changes little or is in standing water. RST consists of large scale progradational parasequence sets, and the sedimentary environment becomes shallower from bottom to up. Finally, the practical study on Songliao basin has been introduced to respectively expound the distribution regularities of oil and gas reservoirs in different system tracts in depression basin and fault basin. LST develops mainly lens-shaped lithologic reservoirs in the steep slope side of fault basin and deep-water area of depression basin. TST forms mainly updip thin away type lithologic oil & gas reservoirs in steep slope belt of fault basin, and forms stratigraphic overlap lithologic oil & gas reservoirs in the gentle slope belt of fault basin and slope zone of depression basin. HST mainly consists of lens-shaped lithologic reservoirs in deep-water area. RST develops mainly stratigraphic unconformity screened oil and gas reservoirs in fault basin, and developes fault block reservoirs and fault screened oil & gas reservoirs in depression basin.Thus, in the combination of theory and the practice, the practicality of the four division about continental sequence stratigraphy has been illustrated.

Ultra-low permeability reservoirs have the characteristics of tremendous development potential and complex pore structure. In order to make definite the microscopic geologic origin of Yanchang Formation in Ordos basin, the authors integratedly use a lot of advanced technology test methods, such as convention thin section, cast thin section, X-ray, high pressure mercury penetration, constant rate mercury penetration, NMR, EMS techniques. The results show that the key elements of cause physical property variation are high cement content, high chlorite content and complex form, halite content, high ferrocalcite content, illite cement upgrowth, lomontite cement corrosion bad. All those elements cause ultralow permeability reservoir showed the characteristics of poor scope-pore coefficient, high displacement pressure, fine pore-throat upgrouth, low movable liquid saturation.

In order to understand deeply the distribution of Mesozoic strata in the southern of East China Sea shelf basin, the processed seismic profiles newly have been interpreted. Combined with the gravity and magnet inversion and the Mesozoic strata correlations between the onshore and offshore, we think that the Mesozoic strata are characterized by extensive distribution and large thickness of over 6 000 m, and ‘thick in the east and thin in the west’ and ‘thick in the south and thin in the north’. The Jurassic strata mainly deposited in Minjiang sag and Jilong sag, which have extensive distribution, stable thickness and high total content of organic carbon for the Mesozoic strata. The Cretaceous strata almost cover the whole southern of East China Sea shelf basin, which show a increasing trend in thickness toward the Jilong sag and low total content of organic carbon . It is inferred that the Jilong sag could be a target with good hydrocarbon potential for Jurassic strata, while Taibei low uplift could also be a hydrocarbon prospecting area.

Due to the low-permeability and tight sandstone reservoirs, as well as the huge thick insulating layer formed between the source rocks and the shallow reservoirs（Shihezi and Shiqianfeng Formation）of Upper Paleozoic in northern Shaanxi slope, Ordos basin, it is significant to study on the natural gas migration channels and it’s accumulation model. Based on the core and micro-fracture observation, logging interpretation, porosity-permeability analysis, and the analysis of diagenesis together with fractureforming time, we have focused on the matching relationship between fractures distribution in the insulating layers and the natural gas pools in the shallow reservoirs. It is believed that the mainly sheering fractures, developed between Late Jurassic and Early Cretaceous, improved permeability and provided migration channels for natural gas synchronously. According to the studies above-mentioned, it is proposed that the shallow gas reservoirs have a good coupling relationship with fractures in the insulating layers on time and space. Based on the fracture migration and sandstone storage, a natural gas accumulation model was presented to show the reservoirs of Shihezi and Shiqianfeng Formations, which is named as lithologic-fractural gas reservoir.

Based on high-resolution 2D and 3D seismic data in Qiongdongnan basin, in northern South China Sea, the characteristics of mass turbidity depositions (MTDs) in different parts of the basin, from the slope system to abyssal plain, have been studied. The result shows that the characteristics of MTDs are different from the eastern to western part in Qiongdongnan basin. In eastern part, the head of MTDs is characterized by the slides, with little or no deformation, and the MTDs are of small scale. While in the western part, chaotic seismic facies and intense erosion are the main features of the head of MTDs, and the MTDs are of large scale, meanwhile, there is a series of parallel or sub-parallel thrusts in the strongly deformed strata in the toe of MTDs. There are mainly two reasons for the differences. Firstly, comparing to the eastern part, the western part of the basin has steeper slope gradient, which is favourable for the development of MTDs. The second lies in the morphology of the basin. The southern high stops the MTDs transporting along the slope. According to the relationship between the head of MTDs and the faults along the shelf margin, the earthquake related to reactivity of the faults is one of the triggers for the development of MTDs.

The genesis of oil-associated CO₂ and its impaction on the exploration of oil reservoir and the dynamic accumulation for oil and gas have been investigated by studying on the oil-associated gas and the dawsonite-bearing sandstones in Changling depression, southern part of Songliao basin. The characterists for oil-associated CO₂ in southern part of Songliao basin are showing a content of CO₂ between 1.57% and 75.25%(most of which are higher than 20%), with δ¹³C_CO2  values from -9.90‰ to -4.00‰, and R/R_a values in the range of 0.95-4.46. It is suggested that the content of CO₂ in oil-associated gas is high, and most of the CO₂ is mantle-magmatic origin. When there is a large-scale mixed CO₂, a secondary oil reservoir will form owing to the displacement of crude oil by CO₂. The scenario of oil displacement by mantle-magmatic CO₂ has been recored by the typical profiles of oil and gas reaervoir in south of Songliao basin and the primary hydrocarbon inclusions in dawsonite cements. Therefore a new exploration idea is made to looking for the secondary oil reservoirs origined from oil displacement by CO₂ within the place mixing with mantle-magmatic CO₂ and oil reservoir.

Research on the uplifts tectonic history is significant for hydrocarbon exploration. This study aims to investigate the evolution of Dongsha (DS) 25 uplift in Baiyun sag, Pearl River Mouth basin, by integrating and comparing with growth strata, back-stripping technique and remnant tectonic subsidence approach associated with tectonic evolution. The growth strata in terms of the strata thickness variation, seismic reflections terminal geometry indicate that the development of the DS25 uplift could be divided into several main stages. Besides，resorting to back-stripping technique, we interpreted subsidence history of the DS25 uplift. Furthermore, by combining with estimation of remnant tectonic subsidence, the movement and development period of the uplift are accessed. By comparison with the above three methods, we integrated the major tectonic events interfaces deduced from growth strata, rapid or weak subsidence stages, the uplift ascending or subsiding movement etc., and presented that the DS25 uplift experienced following five stages. From 65 Ma to 30 Ma, the uplift suffered strong erosion. Before 30 Ma, the DS25 uplift underwent strongly uplift. From 30 Ma to 23.8 Ma, it experienced weak subsidence. From 23.8 Ma to 10.5 Ma, it subsided rapidly,which can be subdivided into three episodes according to different subsidence rates. From 10.4 Ma to present, the uplift was affected by the Dongsha movement and kept continuously ascending.

The Songjiang Cu-W-Zn polymaetallic deposit, early discovered and exploited in Northeast China, has already become a crisis mine for lasting exploitation. Comprehensive analysis on regional geological background, deposit characteristics, and especially the associated rocks’ geochemical characteristic analysis indicate that the deposit belongs to the contact metasomatisc deposit, and the granodiorite colsely associated with the mineralization is the typical product of island arc or active continental margin tectonic setting. The chondrite-normalized REE patterns of the granodiorite, skarn and marble show a great commparability. Moreover, the W and Mo elements mainly originated from the granodiorite, and the Pb element mainly came from the carbonate. While the Cu, Zn elements might originate from both, and the Cu element tend to come from the latter more, the Zn element from the former more. These conclusions can explain the obvious mineral zonation from the granodiorite to carbonate：Mo-W, Fe-Cu, Cu-Pb-Zn and Pb-Zn in Songjiang polymetallic deposit.

Effective prospection can be take using phytogeochemistry in forest cover area. The study of phytogeochemistry in Duobaoshan copper metallogenic field and adjacent area has been carried out. The samples are common plants in the plant samples measurement and taken from roots, stems and leaves, respectively. The rock and soil samples were collected from the same place with plant samples. The analytical method of the plant samples is ICP-MS. Obvious phytogeochemical anomalies can be recognized by the metallogenic elements contrast method and total enriched coefficient(TEC). The phytogeochemical anomalies have genetic relationship with the mineralization proved by the shielding coefficient (SC) and the correlation analysis of mineralized rock, soil and plants. There are some interfered factors in phytogeochemical exploration. The phytogeochemical samples can be determined by the distribution of elements in the plant organs. The contrast coefficient(CC), combination contrast coefficient(CCC) and shielding coefficient(SC) have been used to select effective indicator plants. It can be concluded that platyphylla and lespedeza are the effective indicator plants in Duobaoshan copper metallogenic field. Phytogeochemical exploration in Daxing’anling forest cover area is practicable.

Studying the rules of metallogenic elements fractal distribution is an important method to illustrate the mineralization enrichment.The method of rescaled range analysis (R/S) was applied to study the variation trend with the sampling scale, and to explore into the relationship between Hurst index and mineralized intensity, in the drifts on -210 m level of Dayin’gezhuang gold deposit in the Jiaodong gold province, China. The results show that there exists obvious differences among the Hurst indices of Au grade sequence, greater than 0.5, and the Hurst indeices are greater than 0.65 in parts with continuous mineralization or discontinuous ones concentrated. These indicate that the sequence of the stochastic process is of scale invariant and long-range correlations, and the continued strength of the sequence is consistent with the mineralization, which can provide a new effective method for quantitative identification of regional metallogenic strength.

The Gengzhuang gold deposit, one of the typical gold polymetallic deposits in northeastern Shanxi Province, occurs in Yanshanian crypto-explosive breccia body. The studies of fluid inclusions indicate that there are five types of inclusions in the quartz of different metellogenic stages, i.e. gas-rich aqueous, H₂O-rich aqueous, three-phase CO₂-bearing, three-phase daughter-mineral bearing and single-phase aqueous fluid inclusions, and the mineralized fluids are of H₂O-CO₂-NaCl type. The various types of inclusions formed in ex-metallogenic stage have similar homogeneous temperatures, which indicates that the fluid experienced boiling or aqueous fluid immiscibility. The major metallogenic temperaute is about 170-180 ℃. Combined with isotopic composition and characteristics of gold minerals, we can conclude that the Gengzhuang gold deposit belongs to medium-low hydrothermal gold deposit related to the Yanshanian sub-volcanic activities.

Slow-ultraslow spreading Southwest Indian Ridge (SWIR) is an ideal place to study the relationship between geological structure with mantle partial melting due to the presence of abundant transform faults and segmenting the ocean ridge. Studies on abyssal peridotites from 6 dredges in the ridge segment between the Gallieni transform fault (TF) and Gazelle TF in SWIR reveal that the Cr^# of spinel ranges from 0.194 to 0.329, corresponding to the degree of mantle partial melting from 7.6% to 13.0% which is very low in the global oceanic ridge. The degree of mantle partial melting is controlled by transform fault and the enhanced melt extraction in the segment center, which is shown as greater degree of mantle partial melting in the ridge segment center than near the transform fault. Comparison of the studied area with other ridges shows that both the Cr^# values of the spinel and the degree of mantle partial melting decrease with the decrease of ridge spreading rate. The relationship between mantle partial melting and ridge spreading rate will be estimated more accurately after the correction of the transform fault effect.

LA-ICP-MS zircon U-Pb age and geochemical data are presented for the Mesoproterozoic diabase from Tonghua region, Jilin Province, with the aim of constraining the Mesoproterozoic tectonic setting in the northeastern part of the North China block and its relationship with the break-up of the Columbia supercontinent. The analyzed zircons from the diabase show euhedral crystals in shape, and yield high Th/U ratios (0.21-1.45). Their REE patterns are characterized by depletion in light rare earth elements (LREEs) and enrichment in heavy rare earth elements (HREEs), as well as positive Ce anomalies and negative Eu anomalies, indicating a magma origin. Zircon U-Pb dating results exhibit that seven analyzed points constitute a discordant line, with the upper intercept age of (1 244±28) Ma, which represent the forming age of the diabase, i.e. Mesoproterozoic. Geochemically, the samples from the diabase have SiO₂=49.3%-49.5%, Mg^#=42.2-42.6, and TFe₂O₃=13.6%-14.1%, and belong to tholeiitic series. Their trace elements are characterized by enrichment in LREEs and large ion lithophile elements (LILEs), and depletion in HREEs, and weakly depletion in Nb and Ta and enrichment in Ti, as well as no obvious Eu anomalies. Ba/Nb and La/Nb ratios of them are 15.8-17.3 and 1.15-1.20 respectively. Based on the above-metioned evidences, the Mesoproterozoic diabase is derived from the partial melting of lithospheric mantle with the involvement of the melts from the asthenosphere mantle. Combined with the available research on the Precambrian geological events on the northern margin of the North China block, it is suggested that the Mesoproterozoic diabase formed in a strongly extensional setting, as a result of the break-up of Columbia supercontinent.

To determine petrogenesis and tectonic background of the early Mesozoic granites in the Sunwu-Jiayin area, Xiao Hinggan Mountains, U-Pb dating and Hf isotopic composition in zircon grains, major and trace element characteristics in different granites have been analyzed. Due to their zircon U-Pb ages, ages of granites in this area can be classified into two periods: the Late Triassic period(~210 Ma) and Early Jurassic period(187-181 Ma). Geochemical data indicate that the Late Triassic alkali feldspar granite belongs to the aluminous A-type granite, and was originated from partial melting of the newly accreted Neoproterozoic basic igneous crust. The Early Jurassic tonalite-granodiorite and monzogranite have similar geochemical characteristics as the adakite, and were formed by partial melting of the thickened lower crust. The Early Jurassic syenogranite and alkali-feldspar granite are of significantly different characteristics from the cotemporaneous adakite, and were derived from the basaltic crust accreted from depleted mantle during the Mesoproterozoic period. Combining with the regional researching results, it’s suggested that the Late Triassic granite was resulted from the post-orogenic extension after the collision between the North China plate and Siberia plate, whereas the Early Jurassic granites formed in a compressive tectonic setting related to the subduction of the Pacific plate.

²¹⁰Pb and ¹³⁷Cs dating of sediment core and its recent accumulation rates of the Yueliang Lake in the western Jilin Province are investigated on the base of determination of their specific activities. Two distinct ¹³⁷Cs peaks at position of 18 cm and 32 cm were recognized along the sediment core from the lake, both peaks are corresponding to the years of 1986 and 1963, respectively. The calculated mean sedimentation rates of Yueliang Lake during 1963-2006 and 1986-2006 are 0.74 cm/a and 0.90 cm/a. The dating results using CIC,CRS and CFCS models of ²¹⁰Pb are compared, among  them the results with CIC model are distinct with those of ¹³⁷Cs time marks; the dating results with CRS, CFCS models for the sediment with depths of beneath 64 cm are similar, both are in agreement with those of ¹³⁷Cs time marks; while the dating results with CFCS model shows somewhat different to those with CRS model for the sediment with depths of more than 64 cm. The CRS model is adopted for dating the sediment below the depth of 64 cm because of the poor representatives by using CFCS model to date sediment under this depth due to low correlation coefficient of formula fitted by an exponential function for dating. The average sedimentation rates of Yueliang Lake calculated by dated result of CRS model in years of 1835-1898, 1898-1920, 1920-1961 and 1961-2006 are 0.33 cm/a, 1.09 cm/a, 2.21 cm/a and 0.94 cm/a, respectively. The yearly variations of sedimentation rates reflect the natural environmental changes and the influence of human activities around Yueliang Lake and its watershed.

The measured values of Mg isotope ratios using multi-collector inductively coupled plasma mass spectrometry may be effected by matrix elements to certain extent. Some geological samples such as those from the Baiyan Obo ore deposit may have exceptionally high contents of REE, Nb, Fe and Mn. An investigation of effects of matrix elements on Mg isotope ratio measurement has been carried out. The results show that the measured δ²⁶Mg deviates from true value when the matrix/Mg(mass fraction) is over 0.2. Thus it is necessary to resolve these matrix elements before determining the δ²⁶Mg value. Firstly, the protocols established for Mg purification are using AG MP-1 anion exchange resin and 2.5 mL 10 mol/L HCl+0.001% H₂O₂ reagents as loading medium and eluant, the first 2.5 mL eluant contains Mg but no Fe and Mn; and then using AG50W-X12 cation exchange resin and 2 mol/L HCl as loading medium and eluants, the eluant from 2-7 mL 2 mol/L contain Mg but no REE，Nb and other matrix elemts.

Based on AMS ¹⁴C age data, a pollen record from Tramplin section which is Loess-paleosol deposition in south Kazakhstan is analyzed. It displays vegetation and climate history in central Asia in MIS3a stage as below: before 41.4 ¹⁴C ka B.P.，Vegetation was Artermisia desert-steppe and climate was dry; 41.4-40 ¹⁴C ka B.P.，Vegetation was Artermisia steppe and climate turned to be wetter slightly; 40-36 ¹⁴C ka B.P.，Vegetation was Artermisia desertsteppe and climate was dry; 36-33 ¹⁴C ka B.P.，Vegetation was Artermisia steppe and climate turned to be wetter slightly; 33-30 ¹⁴C ka B.P.，Vegetation was Artermisia desertsteppe and climate turned to be drier slightly; 30-28 ¹⁴C ka B.P.，Vegetation was Artermisia steppe and climate turned to be wetter slightly.

The composition of fossil plants from the Bantou Formation of Yong’an, western Fujian Province, is analyzed and summarized. 52 species  (including 21 indeterminate and suspicious species) ascribed to 24 genus have been reported from the formation up to now. Among them, the conifers with spiral scales are dominant; cycads are mainly composed of Bennettitales; ferns are characterized by small and thick pinnules; Ginkgoales are very few, and angiosperms are absent. The fossil assemblage of the Bantou Florais comparatively consistent with that of the Wealden Flora in Europe, the ryoseki Flora in outer zone of Japan, as well as the Early Cretaceous floras from the South Floristic Region in China, such as Zhejiang and Shandong provinces. This indicates that the age of fossil beds of the Bantou Formation is early Early Cretaceous. Meanwhile, most of the species from the Bantou Formation are xerophilous and are mainly distributed in tropical and subtropical zones. They reflect a dry and hot climate character. However, there exists a certain amount of plants inhabited in moist and warm environments. Therefore, the climate of the Early Cretaceous in Yong’an Basin is generally arid and hot, with humid season, according to the paleobotanic data in the Bantou Formation.

Geological disaster occurs frequently in the three gorges reservoir area, but there is little research on causal relationships between landslide and structural characteristics. And the relative relation of a number of individual landslides in the same local structure has been studied rarely by scholars. Based on the application of faultrelated folds theory, combined with the engineering geology researches, regarded Zuojituo anticline and Badong fault as the focal point of study, in this article the relation between local structure and landslide type is studied. It shows that the cause of large-scale landslide is related with local structure type and local structure parts where are subjected to cut by rivers, which control causal relationship between the evolution rule of individual landslide and the whole bank slope by a deeper level, but not only  reflected the control of a single landslide. In working area landslide formation is related to Zuojituo anticline style and Badong reverse structure, and also related to the river cutting local structure part. Therefor the landslides change fundamentally in local part, and have a serious directivity during evolution of bank slope damaging in space.

Three-dimensional elasto-plastic finite element method (EP-FEM) based on strength reduction technique is an effective numerical method to evaluate the slope stability. However, this approach is seldom employed to analyze the stability and failure mechanism for a 3-D slope under complex geological environments and local surcharge. The strength reduction numerical method is extended by combination with several typical cases. The effect of many factors, such as element size, boundary condition, soil strength, local surcharge on the slope top and the seismic loads, on the slope stability and the potential sliding surface is discussed in detail. On the basis of this, a typical 3-D slope including soft interlayer and ground water is investigated to elucidate the failure mode and sliding mechanism under the framework of strength reduction FEM, local surcharge on the slope top and seismic loads are also considered in the present analysis. The calculated results indicate the following understandings: 1)With an increase of cohesion, locations of potential slip surface and out-slip point are respectively far away from the toe and the top of slope; 2)An overall slope failure is observed under a low surcharge, while a local foundation failure is found under a high surcharge on the top of slope; 3)When the groundwater is considered, the slope stability reduces, the slip depth and the volume of sliding body increase; 4)The potential sliding surface shows a fold-line in a 3-D slope containing a soft interlayer， the failure mode and sliding mechanism of the slope is completely different under two cases as local surcharge on the slope top and seismic loadings. For the former, a combined failure mode with vertical shear and horizontal dislocation is observed, while for the latter a horizontal dislocation along the soft interlayer is found.

The average velocity of a debris flow is one of indispensable parameters in control design of debris flow, so how to forcast accurately the average velocity is very important. The BP neural network model is suggested to forecast the average velocity of a debris flow. The average grain size, the debris flow depth, the gradient of the channel and the debris flow density are taken as the input units. The BP neural network model is established by training and forecasting the observation data of Jiangjiagou debris flows in Dongchuan, Yunnan Province. Comparing the forecasting results with the computing results by Dongchuan equation and modified Manning equation, the maximum errors are respectively 27% and 7.3% computing by modified equation and Dongchuan equation, and maximum error of the BP neural network is only 3.2%. The accuracy of the BP neural network is the highest. The method proposed in this paper is feasible and can forecast the average velocity of a debris flow accurately. This method is used to predict the average velocities of debris flows close to Wudongde hydropower station and the result can offer references for the design of debris flow control.

The controlling design of landslides is a complex nonlinear problem, as many factors affect the design process and they influence each other. There is more or less a waste of traditional landslide supporting scheme, it is necessary to optimize the design of different supporting schemes. Based on the annealing improved mutative scale chaos optimization algorithm, a supporting scheme for Ermi landslide is suggested through computer programming technology. Five factors such as anchor channel number, anchor horizontal spacing, anchors numbers, anchor anchoring angle and anchor anchoring drilling diameter are regarded as the optimizing design variables. The engineering cost and safety of slope are the goal of optimization scheme. The calculation result shows that the cost of optimal supporting scheme will reduce 33.17% than the design based on specifications, and safety factor of landslide rises about 3.31%. The chaos optimization design scheme is much more scientific, reasonable, economy and safe.

THM coupling analysis in porous medium has an important research significance in geological sciences such as nuclear waste geological storage, hot dry rock, CO₂ geological storage, etc.，in which numerical method is often required in view of its computational complexity. TOUGHREACT is joined together with FLAC^3D using grid conversion between the corner points and center point as well as three dimension three point Lagrange interpolation methods, and realizes the multiphase and multicomponent fluid-temperature-rock mechanics coupling analysis. In order to verify the efficiency and applicability of the program, numerical model of CO₂ sequestration into underground saline reservoir in Salah is founded, and three years continuous injection of CO₂ is simulated. Fluid migration and reservoir, cap rock mechanics variation underground is evaluated, and the ground surface displacement is compared with measured values by inSAR. Then a further simulation of three-dimensional cylinder injection model of CO₂ sequestration in a basin of West China is done. The applicability of the coupled program TOUGHREACT-FLAC^3D is demonstrated. The results under the influence of mechanics on the injection pressure as well as the displacement of ground surface are reasonable and in a good agreement with the monitoring value, and some other mechanical results are also obtained.

For getting better properties of WC matrix composites, the performance such as the rockwell hardness and bending strength, etc. of 30 WC matrix composites, prepared by 10 different formulas, are tested. These samples were manufactured by the vacuum hot-pressing sintering process using intermediate-frequency furnace under the conditions that sintering pressure is 13 MPa, the heating time is 6 min, and the holding time is 5 min. The influence of WC, copper ZQSn663, Mn, Co, and Ni on the hardness and bending strength properties of matrix are investigated by data analysis. The results indicate that WC is the prime factor to influence the hardness and bending strength of matrix. Internal logic exists between the hardness of matrix and bending strength. The matrix with high hardness has high strength, too. To get excellent performance of the matrix, the proportion of elements by weight should be controlled in formula: WC<59.1%, ZQSn663>25%,3%<Ni<6.5%,0.9%<Co<3.5%,（WC-ZQSn663）<20%.

The decrease of Yangtze River sediment discharge into the sea and the consequent impacts on the tidal flat have become a hot topic in recent years. The objective of this paper is, from the aspect of tidal creek development, to examine the morphological responses as well as its driving factor in Chongming Dongtan. We firstly interpreted tidal creeks from the aerial image acquired in 2008, and then, under the support of remote sensing and geographic information system software, various influencing factors for tidal creeks development were extracted: vegetation index and soil wetness were generated using Landsat Thematic Mapper(TM) image; the slope of topography was calculated from newly measured digital elevation data; and the isogram map of sedimentary size was produced from grain-size data on sediment samples. After doing these, zonal statistics method was used to calculate the average value of influencing factors in 22 tidal creek units. At last, Correlation/regression analysis was applied to quantify the contributions of influencing factors.The result shows that vegetation, hydrodynamic condition，sediment type  are the dominant factor contributing the current distribution pattern of tidal creeks, followed by man-made projects, while topography and deposition rate are not main driving factors for the creeks evolution. The R of creek density with vegetation greenness, normalized differential vegetation index and surface sediment size are -0.910 6, -0.891 9 and 0.873 4, respectively. From this, we can infer that the distribution pattern of tidal creeks would not have a significant alteration even if sediment discharge from the Yangtze River will decreased dramatically in the following decade.

The water-rock interaction during the artificial recharge is an important influencing factor of groundwater environment quality in the recharge aquifer. The laboratory experiment and hydrogeochemical modeling were used to study the mechanism of water-rock interaction during the artificial recharge. The results of the research showed that the TDS of the mixed water decreased and the water type became HCO₃·Cl-Na·Ca from Cl·HCO₃-Na with the increase in the proportion of the recharge water affected by the mixing; the TDS of the mixed water increased and the concentrations of the major ions showed increasing trend as the water-rock interaction proceeded in the same proportion of the recharge water affected by the water-rock interaction, but the TDS of the mixed water was more than original groundwater when the proportion of recharge water was 10% only(up 5%). The sources of major ions dissolved from the experimental medium: Ca²⁺, Mg²⁺ and HCO^-₃ originated from the dissolution of carbonate minerals and Na⁺ originated from the dissolution of halite. The water-rock interaction included the dissolution of calcite, dolomite, potash feldspar, halite, CO₂ and the precipitation of illite during the artificial recharge. The correlation between the dissolved quantity of potash feldspar and the precipitated quantity of illite and the correlation between the dissolved quantity of carbonate minerals and the dissolved quantity of CO₂ were strong with the correlation coefficient 1.00 and 0.78 respectively with a significance level of 0.05. The correlation coefficient was 0.97 between the reacted quantity of silicate minerals and the proportion of the recharge water that showed extremely strong correlation, but the correlation coefficient was 0.52 with a significance level of 0.01 between the reacted quantity of carbonate minerals and the proportion of the recharge water that showed weak correlation. This correlation study above provided basis for determining the mechanism of waterrock interaction， the original way of major ions in the groundwater and the quantitative analysis of the impact on the aquifer medium during the artificial recharge.

Diffusion is the main mode for organic pollutant transporting through composite liners. At present, research about the uncertainty of transport parameters and its effect on performance of liners are lack. The design method of liner thickness is mostly deterministic. Based on the existing research on the transport parameters, the effect of variability of transport parameters on concentration and flux at the base of liner using Monte Carlo method have been studied in the paper. The variability of partition coefficient and diffusion coefficient of organic pollutant through geomembrane can be neglected, while the variability of diffusion coefficient and retardation factor has very significant effect. The result of deterministic method is pronounced dangerous. So it is necessary to study the probability characteristics of diffusion and retardation of organic pollution through soils. Taking toluene as an example, the thickness of the liner is designed, which is 1.71-1.81 times of that based on certainty method. It is more reasonable to design the thickness of the liner through the transport calculation based on probabilistic perspective.

32 water samples in Jinji water source of Wuzhong City are collected and 11 parameters for each sample are analyzed. Based on the analysis of flow field and hydrochemistry of groundwater, both of factor analysis method and hierarchical cluster analysis method are used to evaluate the comprehensive influence factors of groundwater quality. The results of these two methods are relatively consistent, both of which show that the groundwater quality here are mainly controlled by three kinds of impacts. The first kind of impact is from lixiviation mainly controlled by Cl^-, SO^2-₄, Mg²⁺, NO^-₃, and Ca²⁺, which appears stronger in east than west. The relative contribution of this impact is 48.4%. The second kind of impact is from evaporation-concentration mainly controlled by HCO^-₃, Na⁺, EC, TDS, and T-Hard, which appears stronger in east than in west. The relative contribution of this impact is 39.66%. The third kind of impact is from human activities mainly associated with NH₄-N. The last impact has the same spatial distribution as the factories and pollution discharge areas. The relative contribution of this impact is 11.94%. The distributions of three factors show that evaporation-concentration mainly occurs along the Yellow River. The combined effect of lixiviation and evaporation-concentration occur in north of the Han Drainage. Ammonia-nitrogen pollution is obvious along the Nangan Drainage.

Through the introduction of multifractal analysis theory and using the multiplication cascade model, we analyze the multifractal characteristic of the meteorological drought by choosing standardized precipitation index as the meteorological drought index, according to the monthly precipitation data of six meteorological stations in western Jilin Province from January 1957 to October 2010. The results show that the occurrences of meteorological drought in western Jilin Province have multifractal characteristic on the time scales, but the multifractal intensity was different in stations, which showed a certain spatial difference. The multifractal characteristics increase with the order: Changling<Tongyu<Baicheng<Qianguo<Fuyu<Qian’an.

Arsenism is a new endemic disease resulted from drinking the high arsenic groundwater. In order to evaluate the potential health hazards of arsenic in drinking water, field investigations and sample analysis have been finished, the safety threshold of arsenic in groundwater have been discussed. By analysis of threshold, total arsenic content in water less than 0.05 mg/L was determined as the safe threshold of water arsenic in study area. An evaluation model about the risk of groundwater has been set up, and health risk assessment has been carried out. In all samples, the maximum value of individual annual health risks was 2.11×10^-3 a^-1, and health risk of arsenic in 97.06% sampling sites of confined water of Quaternary period were greater than 5.0×10^-5a^-1，acceptable maximum value recommended by ICRP. Confined water of Tertiary is the backup water source，health risk of arsenic in 69.57% of its sampling sites exceeded the acceptable maximum value. Comparison analysis of the risk assessment results and the illness condition show that the results of health risk assessment are similar to arsenism information, which prove the evaluation results are all reasonable.

Gradient detection technology is widely used in the geophysical measurement for its great capacity, high precision and low noise level et al, but there are few methods for interpreting gradient data now. The authors presented a new gradient interpretation method here, called gradient deconvolution method. The new method can obtain the locations of the causative sources with gradient data, and eliminate structural index from the calculation equation and thus avoids the errors produced by improper structural index selection. We tested the gradient deconvolution method with synthetic potential data.The inversion results show that the misfit between the theory and inversion result is less than 5%, and the inversion results are more stable and correct compared to the conventional Euler deconvolution method. At last, we applied the gradient Euler deconvolution method to measured aeromagnetic gradient data, and obtained the distribution of underground iron mine.

Due to the limited calculation space in the magnetotelluric numerical simulation with finite element method(FEM), mesh boundary is generrally truncated. The existence of truncated boundary may make boundary conditions unsatified and thus affect calculated results and precision to some degree. We calculated the responce of one-dimensional and two-dimensional geoelectric models with two-dimension FEM forward program in which the boundaries of researching area are taken as one-dimensional situation with different truncated boundary. There is no effects on calculated results when simulating one-dimension models, because boundary conditions is satisfied naturelly. But to two-dimensional models, the truncated boundary may make boundary conditions unsatisfied and affect the results and precision. With skin depth as measurement of mesh boundary,we calculated and compared the results of some models with different mesh boundary, and at last got the referenced truncated boundary in MT FEM simulation.

The Fourier transformation is adopted to solve directly the Maxwell’s equations and we get the electromagnetic fields excited by the long grounding source on the layered earth model. Results show that the long grounding source is combination of two grounding poles and line current source. The electrical component parallel to the long grounding line can be decomposed into two parts: one excited by the two grounding poles, the other excited by the line current source.The electrical component perpendicular to the long grounding line and the vertical electrical component are excited by only the two poles. For magnetic fields, the component parallel to the long grounding line is excited by the grounding poles.The component vertical to the long grounding line is decomposed into two parts: one excited by the two grounding poles, the other excited by the line current source.The vertical magnetic fields is excited by the line current source. For homogeneous earth model, at large distance, the electrical component parallel to the long grounding line excited by the two grounding poles is equal to the electric field excited by the line current source and the magnetic field perpendicular to the long grounding line excited by the two grounding poles is equal to the magnetic field excited by the line current source. Their amplitude is proportional to the distance between two grounding poles.

Compressive sensing(CS) is a new kind of theory which breaks the limitation of  the conventional Nyquist-Shannon sampling theorem and recovers the complete signal from few data by using the sparse or compressed characteristics of the signal. With the theory of CS, a seismic data recovery model is built in this paper. Based on the measure matrix which is incoherent with the sparsifying basis,a kind of restrained matrix is proposed as to achieve the effects of seismic missing data with gaussian random distribution or nearly gaussian random distribution and hence the sparsifying coefficient of the aliasing seismic data will contain many random noises which is uncorrelated with the effective signal. The full data can be reconstructed from a new adaptive iterative threshold solution and an inverse sparse transform. From the test of the synthetic seismic data and Marmousi 2  model, we verified the availability and feasibility of our method.

The linear traveltime interpolation(LTI) method is based on linear assumption so that its precision depends on grid division, and the rays transported from the reverse direction are not considered when we recalculate traveltime row by row or column by column,and the computation is unstable in the complex models. Here, we put forward two improvements for the LTI method. First, calculating the minimum travel-time of all grid nodes by all-round cycle strategy during ray tracing. Secondly, inserting secondary nodes in the original grid boundary. Model tests show that the all-round cycle strategy of LTI considers the races from all direction, so it’s more stable for complex models.In the case of same grid division, comparing with the traditional LTI, the LTI method with secondary inserted nodes has higher precision that be improved at least an order of magnitude.At the same time, the calculation speed of our method is faster and time consuming decreases more obviously when the grids become smaller.The calculation speed of our method can be n-10n times than the traditional one’s.

This paper represents that the sedimentary rhythm is a primary factor to control the distribution of water flooded zones in the thick-layer sand. The electrical properties of layers in the same well are comparable and the water flooded level discrimination has more practical significance only in the same sedimentary rhythm.The stable mudstone barrier bed is adopted as the separable symbol for different interpretation units that are identified from well logging curve so that only one sedimentary rhythm is contained in each interpretation unit. The average slope angle of resistivity curve and relative center of gravity of density curve are adopted as discriminant parameters for identifying the original sedimentary rhythm by computer in each interpretation unit. The processing results of three sealed core wells show that this method can discriminate accurately the original sedimentary rhythm, therefore, the interpretation coincidental rate is up to 92.5% compared to the manual interpretation.

In view of the problem of XPGR  (cross-polarized gradient ratio) algorithm existed in the ice-sheet freeze-thaw detection, we proposed an improved XPGR  algorithm used in the Antarctic ice-sheet freeze-thaw detection by microwave radiometer.The algorithm used the generalized Gaussian model to automatically calculate the optimal threshold of the dry and wet snow through histogram statistics for the long time series data of  XPGR, which did not depend on the field observations. By comparing and analyzing, we can see that the two results are very similar, but the new algorithm improves the computational efficiency, usability and operability of detecting in the ice-sheet freeze-thaw detection because the algorithm does not rely on field observations. To some extent, the new algorithm can also improve the accuracy of ice-sheet freeze-thaw detection.

Investigating a new clustering methods is always paid more attention by the researchers in statistics and machine learning fields. Noticing that probabilistic distance clustering cannot solve nonlinear clustering problems, the authors proposed a new nonlinear clustering method called kernel probabilistic distance clustering by extending probabilistic distance clustering algorithm with kernel function theories,and then laid out an executing strategy and feasible algorithm of the new model for the unsupervised classification of remotely sensed image data,and finally developed a visual C++ program of the new model for remotely sensed data classification on the basis of GDAL function library for the input and output of remotely sensed data. A TM image with seven bands and 491× 440 pixels in size provided by ERDAS software platform was applied to the experimental application of the new model for unsupervised classification. The authors compared the clustering performances of the new model and its original version in the unsupervised classification of the TM images. The experimental results show that the clustering performance of new model is better than that of the original linear version in unsupervised classification.