Neopaleozoic of Ordos basin attracts more and more attention because of its blanket enriching sandstone and reservoir. We had studied the relationship between the sedimentary filling, sandstone component, volcanic sediment and orogenic belt, suggest that north Ordos basin and Hing Gan Mts.-Mongolia orogenic belt formed a indiscerptible orogen-basin system in Late Paleozoic.The sedimentary systems and sequence patterns of the six super sequence reveal the basin evolution from epeiric sea to intracontinental depression basin. Dickinson triplot of sandstone clastic component indicate the sediment come from north recycled-orogenic belt. volcanic sediment matter recorded the circulation and adjusting of  crust-mantle matter. We suggest that small-scale river-dalta systems of Late Carboniferous-Earliest Permian owing to the terrain assembly，intermittence rifting and low-amplitude uplift, while big-scale river-dalta systems of Permian couple with collision strengthen and cyclicity uplift of the orogenic belt. The long-term complicated  collision process reflected the characteristic of Chinese orogen-basin system，such as microcontinental amalgamation，soft collision，multi-cycle suturing and intensive intracontinental tectonic activities, it is significant for gentle slope forming and sand reservoir widely distribution in Upper Paleozoic ordos intercratonic depression basin.

The marine and transitional sediments were dominated during Early or Middle Jurassic in the Qiaoyuan Formation of Kuitan area in Huilai. The samples were analyzed by the whole rock analysis and the ICP-MS trace elements analysis. The paleosalinity and the change of water depth are showed by the main and trace elements and their ratios, which are impacted by the change of sea-level and positively correlated. Using the values which reflect the paleosalinity and the water depth of m, Sr/Ba,Ca/Mg,B/Ga and Rb/K, the curve of relative change of sea-level of Qiaoyuan Formation was established. The Qiaoyuan Formation shows the sedimentary cycle of two transgressions and the transgressions takes place in the lower and upper part of Qiaoyuan Formation. The samples were analyzed by the ICP-MS trace element analysis and the sandstone mineral composition analysis. The source rocks are mainly from sedimentary rock, basalt and granite of the upper crust with the REE distribution patterns and the La / Yb-ΣREE source rock discrimination diagrams. Based on the Dickinson diagram, Zr-Th, La-Th-Sc, Th-Co-Zr/10 discrimination diagrams and the eigenvalues comprehensive analysis for trace elements, the tectonic setting is the backarc extrusion basin, which with the characteristics of a continental island arc and few passive continental margin component. The sediments are from the volcanic arc belt.

Over the past decade, Yinggehai basin has been in a trough period of exploration. Based on the comparative study method, the formation and evolution mechanisms between Yinggehai basin and Jiyang depression have been analysed. Studies have shown that the two have many similarities: Both of which are controlled by large-scale after the first L-dextral strike-slip fault. The tectonic evolution experienced rift, rift-depression transform period, depression. Developed multiple deposition cycles，deposition and subsidence centers migrated. Depositional systems are diversity. Both have abnormal formation pressure. Therefore, using Jiyang depression successful experience in hydrocarbon exploration for reference to guide Yinggehai basin gas accumulation study will open up a new prospect for gas exploration in Yinggehai basin.

The sequence stratigraphic framework and classify sedimentary facies of Xishanyao Formation are established by the basic principles and technical methods of sequence stratigraphy in Shanle oilfield. On the basis, the distribution characteristics of sandstone and the rules of hydrocarbon accumulation within the sequence stratigraphic framework are analyzed and the lithologic reservoir’s types and distribution are predicted. The results show that: Xishanyao Formation experienced an integral cycle of transgression-regression, and Xishanyao Formation is a third-order sequence, which contains two fourth-order sequences. The formation consists of delta front deposition in lowstand system tract, delta plain deposition in transgressive system tract and lacustrine fine sediments in highstand system tract. In the study area lithologic updip pinch out traps can be found in the increasing base level cycle, and sand lens lithologic traps can be sought on the descending base level cycle. Respectively, the delta channel sand in the first and second fragments of the Xishanyao Formation can form the updip pinch out reservoirs under the affect of the later tectonic movements; and the lacustrine turbidite sand body in the third and fourth fragments of the Xishanyao Formation can form sand lens lithologic reservoirs.

Based on the review of deepwater depositional elements’ research in the world, combined with the exploration practice of Baiyun deepwater area, the deepwater depositional elements in Baiyun deepwater area are studied. The deepwater depositional elements include channel, levee-overbank, sheet sand and mass-transport deposit. The channel is one of the main components of deepwater deposits and the important reservoir in Baiyun deepwater area. The channel fills have been classified into three broad categories: erosional, erosional/aggradational and aggradational channel genetically. The nature of channel-fill deposits varies greatly. Deposits can include gravel, sand, mud, and mixed fill. Levee-overbanks are dominated by muddy and silty deposits, and its trends roughly parallel to the channel, spreaded laterally away from channel, good lateral continuity and poor vertical communication. Sheet sands are deposited at the terminus of channels and are characterized by their lobate external form. Sheet sands can be divided into layered and amalgamated types. Layered sheets are characterized by relatively low net gross with interbedded shale and sandstone beds. Amalgamated sheets are characterized by high net gross, comprising stacked sandstone beds with fewer interbedded shales. Masstransport deposit includes what is commonly termed slumps,s lides, mass flows, debris flows, slope failure complexes and mass-transport complexes,etc. It can erode the underlying strata and widely distributed, and it can also serve as a good seal for oil and gas.

When the oil fields exploration enters the period of high water-cut, fine description of reservoir structure is of great significance to improve the effect of oil exploration. As abandoned channels are important basis for identification of point-bar sand bodies and single channels boundary, the mud or sand and shale inter bedded sedimentary on the top of abandoned channels keeps off fluids in reservoir, so it is essential scientific basis for analyzing reservoir structure deeply and tapping remaining oil to identify the abandoned channels correctly. We take PⅠ31 layer in Xingnan development area for example, by analyzing the plane and section sedimentary characters of abandoned channels, utilizing method of relative depth contour of sand top, combining plane patterns of sand distribution and log curves response characteristics of abandoned channels, 26 abandoned channels of different size are identified in PⅠ31 layer of the area, and the width is generally around 100 m. Compared with gradually disposable abandoned channels, three sudden disposable abandoned channels sand bending degree is even bigger and extension range is shorter, and the sedimentary thickness is between 2 and 8 meters. As the lateral block action of inter bedded sandstone and mudstone or mud stone, the semi-communicated sand body combined with abandoned channels and general channels brings about unbalanced injection and production system for having injection no production or having production no injection. Top of channels sand becomes favorable zone for collection of residual oil, which is the focal points for further excavation.

The oil in Shengbei structure belt of rich hydrocarbon Taibei sag in Tuha basin is sourced from Shuixigou Group and Qiketai Formation lacustrine facies rock resources, and the gas is coal-related gas. Above the hydrocarbon bearing interval of Qiketai Formation, the oil is mainly lacustrine facies oil and the gas is mainly coal-related gas. Below the hydrocarbon bearing interval of Qiketai Formation, the oil is mainly coal-related oil and the main accumulation stage is on Late Tertiary. Allocation relationship on reservoir-forming elements of Shengbei structural belt has controlled the distribution of different oil & gas types in this zone. By means of faults, the lacustrine facies oil of Qiketai Formation in Late Tertiary can preferentially accumulate in the well-physical property of Cretaceous reservoir. From Late Tertiary to Quaternary, the coal-related gas, in the progress of upward migration, can enter the sand with blocked up by heavy crude and short of physical property of reservoir in Kalazha Group and finally generates gas condensate reservoir. Because of the good sealing characteristics of the argillyte in the Middle-Upper Kalazha Group, some of gas migrate continually upward the oil reservoir of Lianmuqin Formation in Cretaceous. Above all, it has nowadays formed the distribution character of oil above and gas below in shallow layer of this area.

The same flow-units have the same properties of rocks and the flow-capacity, and consistent seepage and flood-out characteristics are similar in the development of the well. Using the view of analytic hierarchy, the flow-units of ultro-low permeability sandstone reservoir are divided basing on the work of single-sand-body contrasting, sedimentary micro-faces, inter-layer and seepage-barriers searching, and combining with the reservoir characteristics of low permeability sandstone. Using the method of multi-parameter statistical cluster analysis, the flow-units of Chang4+5²₂ single sand bed of Yanchang Formation are divided to A category, B category and C category. The experiment of micro-water-flooding describes the different of pore structure ，micro-water-flooding seepage features and oil displacement efficiency diversity. And the rationality of classification results is verified by the experiment from the viewpoint of dynamic analysis. It suggests that: A-type and B-type flow-units have the characteristics of thicker of sandstone and higher FZI, good-connectivity, lower displacement pressure, and the flow-unit of A and B are beneficial to higher-yield area in Jiyuan oilfield. The flow-unit of C has bad water-flooding, and is the benefit area of remained-oil distribution and the potential position of increasing productivity.

The solubility of calcite in the diagenesis is closely related to the chemistry of groundwater and the temperature. According to the reaction equilibrium of CaCO₃ and activity of Ca²⁺ in groundwater, the solubility of calcite in different temperatures and pressures could be calculated. The pH value and the temperature of solution are the main factors to control the solubility of calcite. The dissolving tendency of calcite could be judged by the Gibbs free energy. The condition with ΔG<0 in the solution is favorite to dissolution of calcite and that with   ΔG>0 is favorite to deposit of calcite. The ΔG of groundwater in thirty-four wells are calculated, Tahe oilfield. The results show that: present groundwater conditions favor the dissolution of calcite, the calcite tends to dissolute more in west and south area. This water-rock reaction theory can be used to quantitative understand the burial karst tendency and support the reservoir evaluaterating.

Through the study of many domestic and abroad field examples of CO₂ flooding after water flooding, it is discovered that after the injection of CO₂, the water cut of many production wells decreases sharply, and this phenomenon happens across the whole development phase, including the early stage of CO₂ injection which the CO₂ displacing front doesn’t reach production wells, the stage of little gas producing，and the stage of high gas-oil ratio. We take emphasis on discussing the development rules of low permeability reservoir before the breakthrough of CO₂，and on this stage oil-water two-phase fluid flow is the main flow type, and three-phase flow does not exist. The reason is that a majority of the injected CO₂ dissolved in local oil and water. According to the actual oilfield dynamic response and the results of in-house slim tube and long core flooding experiment，we explain the action between CO₂ and oil-water system，finally gain two conclusions. The first is that gas can drive crude oil reaching producers by traveling through local water. The second is that the displacement law is obviously different in different low permeability cores when CO₂ flooding starting from high water cut stage, for the special low permeability cores, the oil recovery before CO₂ breaking accounted for CO₂ total recovery of 73.27%, and after CO₂ breaking the recovery accounted for 26.73%.But for the average low permeability cores, the oil recovery before CO₂ breaking only accounted for CO₂ total recovery of 16.72%, and after CO₂ breaking the recovery accounted for 83.28%.

The characteristic that the methane gas solubility changes with temperature, pressure and salinity is illustrated based on determining the solubility of the methane-rich gas in sodium bicarbonate solution at various temperatures（90-200 ℃）and pressures（20-120 MPa）. On the basis of previous studies, the relationships between the solubility of natural gas and temperature are divided into three stages: ①Slowly descending phase(0-80 ℃)；②Rapidly increasing phase (>80-150 ℃); ③Slowly increasing phase (>150 ℃). With the buried depth increasing, the solubility of natural gas changes in different phases under the synergetic effects of temperature and pressure. When temperature and pressure of formation water are high enough, the dissolving capacity of methane may be closer to a particular limit. Applying solubility regression equation is favor to estimate the boundary of natural gas segregation. There are four accumulation models in China that water-soluble gas is segregated formation water associated with the structure and percolation-related，including lateral phase degassing, fault-diapiric degassing, caprock percolation degassing, structures uplift degassing.

In order to reveal the difference of hydrocarbon generation kinetics characteristics and its geologic application under different experiment conditions, two thermal simulation apparatus (open and closed systems) are employed to pyrolyze coal sample from Songliao basin. According to the relationship between experimental product yields and temperature, the kinetic models of the oil/gas generated from organic matter are calibrated. Then the kinetic parameters obtained from two experimental systems are extrapolated under the experimental heating rate and the geological heating rate, the results show that the TR (transformation ratio) increasing rate of the gas generation under closed system is slower than that under open system, the reason is that the coal sample pyrolysis to gas under open system is mainly primary cracking, but under closed system it is a common result of primary and secondary cracking. For further application, the hydrocarbon generation threshold is calculated, which combined the burial-thermal history of Xujiaweizi and the kinetic parameters obtained from two experimental systems. And the extrapolation result shows that the calculated geological time (115 Ma) corresponding to the threshold from open system is earlier than the geological time corresponding to the actual threshold (110 Ma), and the calculated geological time (92 Ma) corresponding to the threshold from closed system is later than the geological time corresponding to the actual threshold.

Located in Dandong City，Liaoning Province，Sidaogou gold deposit is of medium-temperature hydrothermal type, mainly occurs in the meta-sandstone strata of Liaohe Group of Early Proterozoic era，and is genetically related to the intermediate-felsic magmatic activities of the Yanshan episode. The spatial distribution of ore-bodies was jointly controlled by the NE strike F₃ fault and the Shujing anticline developed in the hanging wall of F₃. The structural ore-controlling regularities are as follows: 1)The ore-bodies occur mainly in the interbedded brecciation zones developed in the Shujing anticline and spatially display in belts; 2)The major ore-bodies display in a broom-shaped way from east to west; and 3)The ore-bodies in each ore belt mainly distribute at the western side of the hinge zone of Shujing anticline and clearly flank dip toward SE with the flank dipping angle between 30° to 35°. Based on this comprehensive study, we propose that the regular spatial occurrences of the ore-bodies in the mining district are closely related to the dextrorotation-oblique thrust motion of the NE faults. All these structural ore-controlling rules have both great theoretical and practical significances to the subsequent exploration work in the mining district.

The study on supergene activity discipline of elements is precedent and basic for establishing method and technology of geochemical exploration. The supergene activities of elements from parent rocks and soils in Huitongshan copper mine of the Beishan region are studied, which includes the variation of elements’ contents and hereditability between soils and rocks. It can be concluded that some trace elements as Cu, Mo, Pb, Zn, Au, Ag, As, Bi, Ba and Sr show distinctive enrichment characteristics in soils derived from different rocks. In the mine, these elements show more strongly supergene enrichment in fine size than in the coarse soil. With the increasing of the distance from the sample to the ore body, the contents of Cu, Mo reduced gently; while the contents of Ba, Sr rose slightly. Moreover, based on contents of major elements, it is proved that material composition and chemical component between coarse soil and the fine one is obviously different. Compared to the fine soil, the coarse has more similar element contents to its source rock. In addition, the analysis of mineral composition of soils indicates there is a positive correlation between elements’ supergene enrichment and the contents of clay minerals, however, a negative correlation between elements’ supergene enrichment and the contents of major rockforming minerals. According to conclusions above, positive and negative geochemical anomalies are determined with sampling media from -4 to +40 meshes, in Huitongshan copper ore district.

The authors analyzed REE contents of the Cambrian carbonaceous rock series in the Mian-Lüe region by using ICP-MS method in order to investigate their geochemical characteristics and genetic implications. Some conclusions can be reached from the acquired analytical data：the carbonaceous rock series show narrow variation in the total contents of rare earth elements (∑REE)，from 167.88×10^-6 to 210.50×10^-6 with an average at 192.20×10^-6；the ratios of LREE/HREE vary from 6.64 to 16.25 with an average at 11.52，showing relative enrichment of LREE and depletion in HREE；the carbonaceous rock series show remarkable negative Ce anomalies， varying from 0.58 to 0.90 (0.78 on average )，suggesting that the carbonaceous rock series formed in a dry and anoxic sedimentary environment close to a marginal sea of continental slope；the carbonaceous rock series also show distinctly negative Eu anomalies, δEu_N=0.47-0.83(0.62 on average)，suggesting that they formed in a passive continental margin environment as products of normal marine sediments under low temperature(<250℃) diagenesis, consistent with the their geotectonic location in the northern margin of the Yangtze platform；according to the diagrams of La/Yb-Ce/La and La/Yb-REE，it is also confirmed that the carbonaceous rock series not formed in a hydrothermal sedimentary condition but in a normal marine condition with their main source materials coming from a continental crust with high quartz content.

This study focuses on the tectonic origin of the Early Permian alkali granites in the area of Wudaogou, Heihe based on its petrological, geochemical and isotopic characteristics. These granites are aluminous to peraluminous in composition and high in Si and alkali, but low in Ca and Mg. They are enriched in Rb, Th and K, but depleted in Ba, Sr, P, Ti and Nb. Their REE distributions are of typical gull-type pattern. Overall, they have features of typical A-type granite and were considered to be formed in an extensional environment after collision of Ergun-Xing’an block with Songnen-Zhangguangcai block. The newly identified Wudaogou A-type granites in the area of Heihe are of great significance to the ongoing study on the Late Paleozoic tectonic evolution and regional metallogenesis.

CO₂ geological storage belongs to environmental protection projects, suitable sites are the important base for CO₂ sequestration safely for long period of time. It is just the beginning stage of CO₂ geological storage in China, there is no mature technical methodological system. So relevant research is being carried out in this paper. Site selection of CO₂ geological storage should satisfy the principles that effective storage capacity is large enough, safe, economy, the site selection should meet the general conditions for environmental protection engineering standard, and the site should not be affected by adverse geological factors. Site selection of CO₂ geological storage in deep saline aquifers could use multi-scale objective approximation method，including planning and engineering stages. Planning site selection is divided into national, basin and target grade stages. Engineering site selection to ensure the suitable locations according to targets selection, comprehensive geological survey, drilling, injection test and selected site comprehensive evaluation. Ranking multifactor index method on the basis of AHP could be used for CO₂ geological storage site selection, and an index system is established, which provides guidance for site selection of CO₂ geological storage engineering in deep saline aquifers of China.

Rock-filled embankment has become a general type of road embankment so that these rock tunnel spoil can be used. It is obviously necessary to carry on a study of highway embankment stability in earthquake prone areas, because it is the new period of seismic activity since Wenchuang earthquake in China. The experiment of small-sized shaking table has some drawbacks because of its size and load-bearing capacity, but it is not expensive and can be repeated. Its outcome is the premise conditions of large-size shaking table and referential experience of engineering practice. The paper presented a small-sized shaking table experiment of rock-filled embankment and the purpose of this experiment is attention to stability in seism. The rock-filled embankment located in stage fluctuation zone of reservoir. The experiment confirmed that water was a critical factor during the highway embankment failure. The inside embankment slope is failure at first before the water level is raised and the outside slope will be failure with the development of shaking. However, the outside slope is failure at first in the condition of high water level. There are strong scouring and undercutting effects during shaking.

To predict the settlement of turfy soil subgrade with the method of traditional non-equal interval models, there are a few shortages such as cumbersome calculation and low accuracy for short-term forecast Especially when there is a slope mutation point in the subsidence curve, it is difficult to meet the prediction accuracy requirements. For the above shortcomings, average step length conversion is used for non-equal interval sequence to obtain quasi-equal interval sequence; the improved quasi-equal interval QGM(1,1) forecasting models are obtained by amending the original settlement data with the method of linear interpolation; and the subsidence curve is divided into two parts to carry out the prediction at the slope mutation point. As is illustrated in the examples, when the improved quasi-equal interval QGM(1,1) models are used to predict turfy soil subgrade settlement, the average errors between predicted and measured values are 2.99% and 0.25% respectively, far less than the results obtained by means of traditional non-equal interval models. The quasi-equal interval QGM(1,1) model with pretty high accuracy for short-term prediction can serve as a reliable reference to settlement control in project.

More and more engineering geological characters of solidified dredger fill are concerned due to the faster increase of number of reclamation engineering. It has been studied that the engineering behavior of dredger fill is mainly influenced by the material composition and microstructure, within which, the latter is indispensable but seldom involved. Taking dredger fill in Tianjin as study sample, indoor sedimentation test in the effect of seepage is performed along with quantificational analysis of microstructure of soil using image processing technology. And then, the changing of evaluation indicators, such as the size of structure element and pore, abundance, and directional frequency are discussed. The result indicates that, with the increase of seepage pressure, the dispersed structural elements of soil become agglomerated elements displaying a variety of oblate but without directing property. Simultaneously, the pores in the soil are diminished and compacted to be globoid ones after losing balance.

Division of geological-hazard-prone area has important significance for scientific geological disaster prevention. Based on the theory of hazard-prone area division, seven evaluation indexes such as quantity of hazard points, topography and geomorphology, geological structure, rock and soil mass type, multi-year average precipitation, vegetation coverage ratio and human engineering activities were put forward. The weight coefficient was determined by putting preference ratio method and entropy method into optimal combination, which was applied into the evaluation of extension theory. A new model of geological-hazard-prone area division named optimal systems weighting law was proposed. The result shows that the division of geological-hazard-prone area of Jilin Province coincides with the practical situation.

In-situ sampling techniques are crucial to keep hydrate samples intact for characterizing the occurrence conditions and reserves of the gas hydrates in permafrost land. Having taken into account the thermophysical characteristic and the temperature-pressure dependence of gas hydrates, we have developed a borehole bottom freezing technique for gas hydrate sampling. This technique can significantly reduce the required sampling pressure and prevent decomposition of the hydrate samples by means of an external cold source which freezes the hydrate cores at the bottom of borehole. The gross structure of freezing sampler is consist of single action, control mechanism and freezing mechanism. The two elementary principles are freezing core by hole bottom and achieving the sample on the surface are analyzed, which analyses the required energy that freezing core for the sampler. The borehole bottom freezing sampling was tested by a trial of core drilling. Success in retaining freezing samples demonstrates that this technique can be applied to obtain freezing samples from the borehole bottom, creating a novel approach for development of in-situ hydrate corers.

Glacier-lake outburst is closely related to temperature fluctuation. With the global warming, it is important to study the relationship between them. The authors try to find out the relationship based on the temperature data associated with 14 glacier-lake outburst events in Tibet. It is found that the outburst is sensitive to acute change in annual temperature. Most outbursts occur at the years with abnormal change in temperature. According to this study, the probability of outburst depends on temperature series in many years. According to the combination with positive accumulated temperature (T) and exponent (a) of fitting curve that is fitted for accumulated temperature, we can distinguish low-possibility outbursts and high-possibility outbursts by power function. The authors recommend long time series of total accumulated temperature and exponent of accumulated temperature curve is effective way to study glacier-lake outburst.

To deeply research and disclose change rules of flood and sediment series at the middle reach of the Yellow River from stochastic aspect macroscopically, a joint distribution model of flood and sediment was constructed with Copula function method and then its application was discussed, based on the time series of flood peak flow that over 6 000 m³/s and its corresponding peak sediment concentration during a flood course from 1952 to 1998 of the Tongguan gauge at the middle reach of the Yellow River. The results show that among the synchronous encounter probabilities of rich-poor state between flood and sediment, the synchronous rich probability is appreciably greater than the synchronous poor probability and the synchronous common probability is the smallest, their values are 25.61%, 24.14% and 8.61% respectively; among the asynchronous encounter probabilities of the rich-poor state between flood and sediment, the probability that flood is common (poor) and sediment is poor (common) is 8.93%, the probability that flood is rich (common) and sediment is common (rich) is 7.46%, and the probability that flood is rich (poor) and sediment is poor (rich) is the smallest, which is 4.43%; and the same recurrence period can correspond to different combination events between flood and sediment. The construction and application of the joint distribution model achieved coupled evaluation and integrated appraisement of flood and sediment during a flood course.

In order to analyze the circulation of karstic water in underground river system, the hydrogeology conceptual model of this system was established, the system has a strong hydraulic connection with peripheral porous media and distribute in saturated zone with centralized discharge. The water movement character and corresponding equation in various aquifer medium was given, also the discrete way and solving method of the model were given. The problems about the porous water and fissure water free water table, conversion between confined and unconfined, the conversion between laminar flow and turbulent flow, time scale and sinkhole were analyzed, the program UGRFLOW09(Underground river flow model) for calculating about water flow motion numerical model of underground river system was compiled. This study shows that the proposed numerical model was effective.

⁴He isotope is an ideal tracer for groundwater dating, but it was generally disagreement with ¹⁴C dating results due to dating scales and multisources. By taking noble gas samples and ¹⁴C samples in the same well from the Quaternary aquifers in Hebei Plain，the results revealed that the concentrations of radiogenic ⁴Herad components ranged from 5.43×10^-8 to 8 994×10^-8 cm³·STP/g by using closed-system equilibration (CE) model. Furthermore, it was found that ⁴He age of groundwater ranged from 8.8 to 55.9 ka and ¹⁴C age ranged from 7.7 to 35.2 ka, which indicated that above two results differed slightly and correspondingly we can concluded that the application of ⁴He dating in Hebei Plain is reasonable.

The soil carbon pool plays a key role in terrestrial ecosystem carbon
cycle. A toal of 217 soil profiles has been collected, a total of 2 170 soil samples were obtained for measuring the average bulk density, moisture content and organic carbon content based on the six-year（2004-2009） environmental investigation implemented in western Jilin Province. The vertical distribution characteristics, reasons and mechanism of soil organic carbon（SOC） under different land use/cover types were analized. The result shows that the vertical distribution of SOC under different land use types has sharply different characteristics, and they can be divided into three types. The decreasing type including grassland, farmland and wetland, SOC of them mostly enriched in the planting layer (0-30 cm), and decreases with depth. Bottomland is under the increasing type, according to the appropriate hydrological conditions and lush vegetation. Meanwhile, SOC of saline and sandy land belongs to the stable type, stay at the lowest standard. The soil organic carbon density of different land use types varies a lot, the general trend from high to low is paddy field, grassland, upland field, wetland, degraded grassland, bottomland, woodland, sandy land and saline land. The soil organic carbon density of paddy field is (169.25±17.70) t/hm²; while, saline land is (26.50±10.00) t/hm². Therefore, the main factors that influence soil organic carbon contents are vegetation biomass, and soil physical and chemical properties.

 The coastal wetlands system of Yellow River Delta was chosen as the research object, both conceptual model and indicator system for the health assessment of coastal wetlands were established based on the analysis of the four functions of the healthy coastal wetlands and the consideration of the coastal wetlands eco-geological environment system characteristics and health responding factors. Based on the remote sensing data and monitoring data, GIS, RS and some other advanced technologies were adopted to analyze the temporal and spatial regularities of distribution of the coastal wetlands of Yellow River Delta. The results show that: healthy, sub-healthy and morbid area accounts for 14.2%, 61.9% and 23.9% in the coastal wetlands health structure of the Yellow River Delta, respectively. During the period from 2010 to 2015, habitat quality in estuarine wetlands will be gradually improved to the healthy direction, but the environmental quality of northern and southern parts of the beach area and the Shenxian’gou flow path in the local areas will have a certain decline by natural and human impacts together. The main influencing factors of coastal wetlands health in the Yellow River Delta are the major regional water cycle process and its spatial and temporal variations under global climate change background, wetlands exploitation and other negative disturbances and the ecological operation in the lower reach of Yellow River. Much more efforts should be given to the ecological operation and restoration in the lower reach of the Yellow River for the purpose of the healthy development of the coastal wetland in the Yellow River Delta.

Three undisturbed samples were collected in intertidal zone in the Taizhou Bay of Zhejiang Province, China. Reactive and pyrite fractions of trace metals in the sediments were obtained using sequential extraction method, meanwhile, acid volatile sulfide (AVS) was measured by cold diffusion method. The results indicated that the degree of pyritization (DOP) of trace metals in the study area was low and trace metals were very active and liable to take part in biogeochemical cycle, but elements differed greatly in degree of trace metal pyritization (DTMP): As and Hg underwent most significant pyritization, Cu, Zn, Cd, Cr, and Ni moderately, and Pb and Mn the least. Factors that controlled the degrees of pyritization depended upon whether there was abundant organic carbon (OrgC) and AVS in the sediments and also upon the presence of an anoxic reducing system. Concentrations of the reactive trace metals were not a limiting factor in the present study.

The study focused on the climatic erosivity time series of past long years in agro-pastoral ecotone of northern foot of Yin Mountain, Inner Mongolia, China, based on the meteorology data of wind speed, precipitation, temperature, humidity and so on. The temporal-frequency multiscaling variations and abrupt change features of climatic erosivity were analyzed by the MHF wavelet method which contributes to reveal the multi-scale variations characteristics of climatic erosivity, as well as the periods and abrupt change points of climatic erosivity series in different time-scale. Meanwhile, the relationship between the sandstorm phenomenon and the wind erosion climatic erosivity was obtained in the meteorology. The results showed that there were obvious staggered features about the variations of climatic erosivity in agro-pastoral ecotone of northern foot of Yin Mountain. Furthermore, it is found that approximate 16-year period-oscillation of climatic erosivity variations is the strongest. In addition, the sandstorm is more frequent where the larger wind erosion climatic erosivity is. Finally, the wavelet coefficients patterns exhibit a strongly reducing trend in climatic erosivity in the future years in long-term, but in short-term, there is a transition from larger climatic erosivity to smaller one.

In Guanting reservoir, biological nitrogen fixation rate (NFR) was measured with acetylene reduction method, the diversity of nitrogen fixation bacteria (NFB) was revealed with nifH gene PCR-DGGE fingerprint. The results showed that biological nitrogen fixation exists in Guanting reservoir, the rates of nitrogen fixation ranged from 0.172 to 9.35 nmol/(m³·d). There was a positive correlation between NFR and NH⁺₄-N (P=0.998, r=0.000), TN (P=0.986, r=0.000), TP (P=0.968, r=0.002) concentrations, respectively. DGGE fingerprint indicated the (NFB) abundance differed between six sites and positive correlations were found between NFB abundance and TN (P=0.737, r=0.094), TP (P=0.787, r=0.063). Shannon-Weaver index varied in a range of 0.80-2.45. During the process of eutrophication in reservior, nitrogen fixation bacteria diversity increased with the nutrient status and thereby NFR enhanced. In addition, biological nitrogen fixation could aggravate eutrophication in Guanting reservoir.

The pretreatment method based on catalytic pressure in neutral conditions was used for leaching gold and copper concentrates. The results suggested that 99.4% of Cu could be leached out from gold and copper concentrates when temperature was 180℃, partial pressure of oxygen was 1.8 MPa and amount of catalyst was 0.14 mol/L. The total of Fe was only 3.52 g/L in leachate, which was beneficial to recovery of Cu in the follow-up process. In the residue, 98.2% of Au and 90.3% of Ag could be leached out by chloride leaching gold process. The pretreatment process was straightforward and the environmental benefits.

The white carbon black was successfully prepared by using sodium silicate derived from oil shale ash via the traditional precipitation by hot-air drying. The effects of synthesis condition on the formation of white carbon black were also investigated. The results showed that the optimal synthesis conditions of white carbon black are as follows: SiO₂ concentration of 8.1%, sulfuric acid concentration of 1.5 mol/L, aging time of 8 h, reaction temperature of 70-80℃, and pH value of 8. The transmission electron microscopy (TEM) images indicated that the white carbon black has an average diameter of about 50 nm. In addition, it was observed that limited amount of particles were agglomerated.

Four classical edge enhancing methods in gravity and magnetic exploration field are compared: Tilt derivative, horizontal gradient of Tilt derivative, Theta angle and normalized standard deviations. All of them can amplify high frequency anomalies related to edges. An  approximate edge detector can be used in enhanced contour maps where local maximum relates to geology edge. While Canny edge detector can deal with enhanced map where inflexions relate to geology edge. Module tests in theory show that, comparing Canny edge detector for Tilt gradient map with approximating edge detector for other edge enhance map, the edge positions detected with the former accord with the real positions more accurately and there are fewer fake edges. In the applications, use is made of this method to deal with the local gravity of Meishan iron ore and to help approximately locate the boundary of iron bodies.

Mineral magnetic parameters and contents of SiO₂（w(SiO₂)） were measured on sediments of upper reaches of Haohe River and quartz tail-sands. Results show that w(SiO₂) of the sediments is more than 80%. It proves that sediments of upper reaches of Haohe River has been seriously polluted by quartz tail-sands. Magnetic measurement results show that the magnetic characteristics for sediments and quartz tailsands are basically the same. The main magnetic mineral of the two kinds of samples is ferrimagnetic magnetite, and the content of magnetic mineral is low. The magnetic grains of the two kinds of samples are wide, mainly in the 0.1-5 μm region. When a lot of the quartz tail-sands is rushed into Haohe River, its effect weakens the magnetism of sediments, while the magnetic grains become bigger. The w(SiO₂) of sediments and the magnetic parameters(χ, SIRM and χ_ARM) have negative correlation(-0.83≤R≤-0.61). It shows that the magnetic parameters might reflect degree of sediment’s pollution by quartz tail-sands. The lower the scale of the magnetic parameters, the more seriously sediment will be polluted by quartz tail-sands.

The study of efficient inversion method was carried out for continuous formation, targeting at improving the inversion precision and efficiency of 3-dimensional (3D) induced polarization (IP) data with waved geometry. Blocky continuously varied parameterization based on tetrahedral element was developed for the continuous changed resistivity model with fluctuated geometry. The stability and resolution of inversion was improved by including model smoothness and background prior information. The inversion efficiency was achieved via decreasing the dimension of inverse problem, memory compression of the matrix of linear equations, and calculation of sensitivity matrix with a combination of reciprocal theory and quasi-Newton method. Finally, the effectiveness of the inversion method was tested by two examples. The numerical results show that the inversion converges within 6 iterations and takes very little computational time. The inversion result can give a good interpretation of the anomalous targets. The inversion software developed can be used to interpret the real data.

Bai-58 well of Baiquan area on the northwestern margin of Junggar basin is a complex fault-block area cut by multiple faults with variable dip of layers and the distribution of multiple faults. The old 3D seismic data section in the Bai-58 well region show the poor continuity of seismic events, poor imaging data near the fault zone, the unclear contact relationship between strata. And it is difficult to explain fine structure. In order to obtain the fine structure of sedimentary in the study area, we use various processing technologies such as pre-stack multi-domian noise attenuation and non-linear pre-stack time migration for doing high-resolution 3D seismic reflection data on base of the analysis of the raw seismic data and problems. New results reveal the development characteristics, spatial distribution patterns and the relationship of surface composition of Bai-Wu fault. According to the section showing the strata thickness, structural feature, and characteristics of the seismic reflection wave group, the study area is divided into the three major structural layers, which are Permian, Triassic, Jurassic-Cretaceous structural layer. The different tectonic feature of the three major structural layer, is divided the study area into the western thrust belt, central fault-step zone, and eastern slope tectonic zone.

With the development of the computer, full-waveform inversion based on frequency-domain modeling attracts researchers’ attentions again, accordingly, PML boundary conditions for second-order acoustic wave equations and variable grid parallel computation in frequency-domain modeling are studied. PML boundary conditions is a relatively ideal absorbing boundary method and is usually used in solving the stress-velocity equations in time domain, however, for frequency acoustic wave modeling, second order displacement equation is more commonly used. We derived frequency domain second-order displacement equation PML boundary conditions from the first order acoustic wave equation PML boundary conditions and present satisfactory results of simulation examples. A single shot frequency domain modeling is implemented by solving a number of linear equations followed by an inverse Fourier transform on the records, so the frequency domain parallel computing can be performed either in different shots or in different frequencies. According to the frequency dependent character, we study the variable grid spacing computing method, using large grids in low frequencies, and small grids in high frequencies, which is one of the advantages compared to time domain modeling, and reduce the number of computation and memory consumption in the premise of ensuring the quality of simulation.

The design of the appropriate completion technique for a horizontal wellbore in sour gas field is dependent on borehole stability, which is constrained by in-situ stress, rock mechanical parameters and well trajectory. It is feasible to recommend the appropriate completion method for sour gas fields in the northeast Sichuan based on the relationship between in-situ stress and well trajectory. A predictive model was established, which useed the Drucker-Prage criterion and equivalent plastic strain theory. Influence of in-situ stress on horizontal borehole stability with different trajectories and drawdown pressures were numerically simulated, which took the effect of strength reduction and pressure depletion into consideration. Results indicated that rock strength of the northeast Sichuan marine strata is high enough to maintain borehole stability during production. With the increase of drawdown pressure, equivalent plastic strain increased gradually, but the total strain was relatively small. Gas reservoir pressure depletion and strength reduction caused by acidification played an important role in well stability and sand production tendency. Base on the study, appropriate completion method for sour gas fields in the northeast Sichuan was recommended. 1)If well trajectory was coincident with direction of horizontal stress, open-hole completion was recommended,2)If angle between well trajectory and direction of horizontal stress was less than 30°, open-hole completion could be used, but drawdown pressure should be strictly controlled, and 3)if the angle was more than 30°, cased completion should be used. The results have been applied in Puguang for 6 horizontal wells.

The authors present a method to extract the phase slowness from dispersive waves provided by sonic logging. The dispersion curve can be acquired by maximizing the frequency-slowness coherence value at each frequency. The projection of dispersion curve on slowness axis is the histogram of formation slowness. The method is based on matching a fitting function to the slowness histogram using method of nonlinear least squares. The slowness of edge location in the best fitting function is the true formation slowness. As an example, the method is employed to process both theoretical dipole wave and field sonic logging data. The phase slowness of dipole wave and the formation slowness are almost the same for theoretical dipole wave; the phase slowness of dipole wave matches with the curve of slowness-frequency projection for field sonic logging data. It is reliable and effective for processing dispersive wave data with this method.

The Zhalong National Nature Reserve (NNR) that located in Heilongjiang Province was selected as a study area, five temporal ETM+imagery covering the study area were used as material for wetland mapping. An evidential reasoning (ER) approach that built on Dempster-Shafer theory was introduced to combine the five images. We used a new algorithm named minimum distance to generate evidence support from ETM+image. Results indicated that ER was an effective approach to integrate multi-temporal imagery for wetland mapping. Compared to classification results of single image based maximum likelihood classifier (MLC), the improvement of overall accuracy by ER approach was apparent (2%-12%).

Traditionally, minerals identification of thin sections under the microscope is carried out with visual interpretation and qualitative description. It is subjective and difficult to quantify.We introduce a digital image processing technique to minerals analysis, and multiresolution segmentation is employed to mineral features extraction and analysis on the petrographic image of quartz sandstone. Firstly, we obtained the boundary of the quartz grains using multiresolution segmentation. Then the features of quartz particles were extracted, including size, contents, perimeter, long axis length and orientation, the long axis and minor axis ratio，roundness and shape index; pixel statistics shows quartz content are of 47.07%, less than the matrix, which floating in the matrix with matrix support structure; the long axis of quartz ranges from 50 to 604 pixels, which shows the size of quartz grains is poorly sorted; and the roundness is 0.27-1.82, shape index value of 1.19-2.46, roundness and shape index is of small value, that means it has certain psephicity. This study shows digital image processing based on multiresolution segmentation can achieve the quantitative description for the minerals features, and it is helpful for petrographic images understanding and analysis.

A geospatial sensor network combines wireless sensor network with GIS, GPS and satellite remote sensing efficiently, but at present, it has no uniform architecture. So an architecture of geospatial sensor network oriented to water quality monitoring was proposed, and the design and implementation of data management subsystem is the main content. The software design of data management subsystem was based on service oriented architecture (SOA), since the monitored data is distributed, multiple sourced, and heterogeneous. Rich internet application (RIA) was the main developing mode in the software, so it has auto update, loading balance, and some other advantages. Compared with the traditional water quality monitoring approaches by the application in Ontario, Canada, this architecture can monitor more data, and visualize them more directly.