The sedimentary and diagenetic characteristics of reservoir were special in Bongor basin, Chad. Based on regional tectonic evolution and various basic data such as cores, thin sections, mud logging, test data and so on, the authors do systematic research on the sedimentary-diagenetic characteristics of reservoir sandstone. The results show that series of NW-SE depressions were formed during the early Cretaceous rifting stage by the NE-SW extension, which controlled the sediment source, the sandstone distribution patterns and formed lots of fans. These fans should be classified as subaqueous fans and mainly distributed along the boundary faults. The structure inversion of the Late Cretaceous induced large amount of erosion and uplifted the reservoir greatly. It also influenced the normal diagenesis process of the reservoir. Due to the tectonic evolution, the hydrocarbon infilling and compositional maturities, their mechanical compaction and cementation were relatively weak but the dissolution was relatively common. The diagenesis of reservoir sandstone was still under the substage of the middle diagenetic stage and has the good quality: medium porosity, mediumhigh permeability. The quantitative evaluation of the relationship between porosity and burial depth revealed that the depth limit of the effective reservoirs is much deeper than that of the present oil pay zones and the deep reservoir still has a good prospect of exploration.

On the basis of the problems existed in analyzing the concepts of secondary pore zone and secondary pore development zone, this study redefined concepts of secondary pore zone, secondary pore development zone, porosity high-value zone and porosity low-value zone, analyzed the characteristics of secondary pore development zone in nearshore subaqueous fans reservoir in the middle part of Es₃ to Es₄ in Minfeng area, Dongying sag, and discussed the proper way to recognize secondary porosity and its guidance significance in deep oil and gas exploration. Secondary pore refers to the new pore formed during the burying process. Original intergranular pore and the solution pore around it should be distinguished as primary pore and secondary pore when recognizing the types of reservoir pore space. Secondary pore zone is the zone that has secondary pore on porositydepth record section, which corresponds to a depth ranging in vertical, and shows a porosity region horizontally. Secondary pore development zone refers to the high porosity reservoirs that have more than 50% secondary pore. Secondary pore development zone includes three meanings: Secondary pore development zone contains more than 50% secondary pore; The reservoir porosity is higher than the effective reservoir porosity cutoff in the secondary pore development zones; High porosity reservoirs concentrate into belts in a depth range on the porosity-depth record section, with the porosity envelope curve bulges to the porosity high-value zone direction. There are four secondary pore development zones in nearshore subaqueous fans glutenite reservoir in the middle part of Es₃ to Es₄, Minfeng area, Dongying sag. The depth ranges are 2 800-3 500 m,3 750-4 050 m,4 300-4 500 m,4 700-4 900 m. Secondary pore development zone and porosity high-value zones are the vital targets of the middle and deep oil-gas exploration. However, the authors think that the present porosity low-value zone on porosity-depth record section may be a neglected exploration target.

Xihu depression is a sub-depression of Donghai basin, China. Pinghu Formation developed in late faulting-subsiding period is a suit of coal-bearing series, and the most important source rock in Xihu depression. On the basis of comprehensive analysis of seismic, drilling, logging and core data,three long-term and ten mid-term base level cycles are recognized. The main sedimentary environment developing coal seam are tide influencing delta plain, interdistributary bay of tide influencing delta front, supralittoral zone, and interdistributary bay of braided delta front. These long-term base level cycles are mainly positions where coal seam growth, and the long-term base level cycle LSC2 is the most developing place of coal seam. The place of coal seam in short-term base level cycle was controlled by size of accommodation space. Coal seams were mainly developed in middle-upper part of decreasing short-term base level cycle on the background of high accommodation space; whereas coal seams were mainly developed in the maximum accommodation space of short-term base level cycle on the background of low accommodation space.

Many lenticular sandbodies developed in dark shales of Shahejie Formation in Zhanhua depression. With analysis of cast thin section, X-ray diffraction, scanning electron microscopy， fluorescent light and cathodoluminescence micrography, diagenetic differences from the exterior to the interior of the typical lenticular sandbody were analyzed by dense sampling from 3 199 m to 3 201 m. There was intense dissolution in the sandstones, but carbonate cementation, quartz overgrowth and feldspar overgrowth decreased from the exterior to the interior of sandbody. The later carbonate cement formed a tight cemented layer, which decreased the sandstones porosity. However, the oil and gas accumulation was not impacted by the tight cemented layer. By analysing the sequence of diagenesis and the oil accumulation, we find the cementation was later than the oil accumulation. The secondary porosity of the sandbody showed the early intense dissolution, which supplied enough space for the hydrocarbon charging peak and decreased the capillary resistant force. After the oil and gas accumulation, the later carbonate cement decreased the exterior sandstones porosity and increased the capillary resistant force, which depressed the oil charge and protected the reservoir. In a word, not all tight cemented layers near the exterior sandbody could disturb the oil and gas accumulation.

The sulphur isotope of anhydrite and glauberite in Member 4 of Palaeocene Shashi Formation in Jiangling depression changes between 25.2‰-32.6‰, which is much higher than the sulphur isotope of synchronism sea water (20‰). Through the study of strontium isotope in evaporate in Member 4 of Palaeocene Shashi Formation and the comparison analysis of Mg, Ca, Sr, Ba content and Sr/Ba, Mg/Ca ratio, the authors propose that lake basin of Jiangling depression is closed continental salt lake facies. Primary glauberite, typically warm facies saline minerals, is widely developed in this formation. The Fe₂O₃/FeO ratio represents drought climate. This feature reveals that Palaeocene Shashi Formation of south Jiangling depression in Jianghan basin is drought and warm paleoclimate. In drought and warm paleoclimate condition, because of the low supply rate of sulphate deposites, the sedimentary environment at that time is closed to sulfate. Through the study of main trace element, including Fe, Mn, Al, Mg, Ca, Ni, V, Co, Cu and Fe/Mn, (Fe+Al)/(Ca+Mg), w(V+Ni+Mn), V/(V+Ni), Ni/Co,Cu/Zn ratio, it reveals that the environment of Member 4 of Shashi Formation is anoxic and reducing environment under wave base of lake basin, which is relative deep layered lake for years. A lot of anaerobic bacteria lived in this anoxic sedimentary environment. Under hypergene condition (≤50 ℃), anaerobic bacteria reduced SO^2-₄ to H₂S, which reacted with metal ion to form sulfide or escaped from the system. In addition, the continental environment at that time is relative closed to sulfate. This cyclicprocess caused the high sulphur isotope value of anhydrite and glauberite, which was also the most important sulfur isotope fractionation process in the study area.

Trachyte is one of the important deep-gases reservoirs among volcanic rocks in Yingcheng Formation of Xujiaweizi fault depression, Songliao basin. Core, drill and seismic data exhibit that trachyte always erupt at higher location and flow to low-lying areas. In general, the thickness increases toward crater. Major element, trace element and isotopic geochemistry studies indicate that the trachyte belongs to shoshonitic series. The trachyte are prominently enriched strongly incompatible elements such as Rb, Ba, Th, U, REE, and have low initial ⁸⁷Sr/⁸⁶Sr (0.704321-0.705395) ratios. All ε_Nd(t) values of the trachyte are all positive and have a narrow range (3.36-3.83), but they have an analogical radiogenic Pb. The mean of (²⁰⁶Pb/²⁰⁴Pb）_i,（²⁰⁷Pb/²⁰⁴Pb）_i，（²⁰⁸Pb/²⁰⁴Pb）i are 18.43，15.51 and 38.23, respectively. The features of geochemical data indicate that the trachyte magma are derived from partial melting juvenile crust following fractional crystallization without crustal contamination. Hydrothermal gases continuously gather into trachyte after many times eruptions. The trachytes would be crypto-explosive when the pressure is not large enough to bear. The crypto-explosive breccias are formed when the autobreccias are cemented by hydrothermal fluids, which can creat many cracks and inter-granular space.

Numberous endogenetic gold deposits are found in the epicontinental region in Northeast China, and they have attracted more attention and research efforts from both domestic and international economic geologists. These deposits are featured by the characteristic of complex and obviously multistage mineralization. Based on systematic study on geological features and metallogenic epoch of these endogenetic gold deposits in the area, the present paper has divided the gold deposits into four main types: mesothermal, contact-metamorphic, porphyry gold-copper and epithermal gold deposits. They were formed in three important ore-forming epochs at 170-160 Ma, 130-110 Ma and 110-90 Ma. Based on isotope geochemistry, we concluded that that the metallogenic material of the mesothermal gold deposit was derived from  the lower crustal source and its mineralization was closely related to lithospheric thinning and delamination of the continental margin, a processes triggered by the subduction of the PaleoPacific plate in the Early Mesozoic Yanshanian orogeny. The metallogenic material of the contactmetamorphic gold deposit was derived from the younger crust and the mineralization was relevant to contact metasomatism of magmatic process under extensional setting of the lithospheric thinning and delamination, which caused by the subduction of Paleo-Pacific plate. However, metallogenic material of porphyry gold-copper deposit and epithermal gold deposit manifested as crust-mantle mixture. Their mineralization occurred in the tectonic transition period from Asian continent subducted by the Paleo-Pacific plate towards the due north to the Izanagi-Farallon plate subduction toward west.

The Balkhash metallogenic zone in Kazakhstan is an important porphyry Cu-Mo metallogenic belt in the Central Asia metallogenic domain. In this paper, zircon SHRIMP U-Pb dating, major, rare earth and trace elemental geochemistry, and Sr and Nd isotope tracing of porphyry granitoids from Kounrad, Borly and Aktogai large and super-large porphyry Cu deposits, provide important informations on porphyry Cu metallogenic time and tectonic environment of the zone. Two stages of metallogenesis, one at ~327 Ma with the formation of Kounrad and Aktogai deposits, and the other at ~316 Ma with Borly deposit, are determined. The porphyry granitoids from this zone are mainly high K calc-alkaline series volcanic arc granite, some of them are adakite-like in trace element geochemistry. ε_Sr(t) and ε_Nd(t) of granitoids from three deposits are in the ranges of -6.35-34.03 and -0.46-5.53, respectively. Their Sr-Nd isotopic signatures indicate that porphyry granitoids from Kounrad and Borly were derived from a mixing source between the depleted mantle and the ancient continental crust, whereas that from Aktogai were derived from the depleted mantle directly. Via comparison of the Balkhash metallogenic zone and Junggar metallogenic zone, they are considered to be formed in the same Late Paleozoic Balkhash-Junggar porphyry Cu-Mo Metallogenic zone.

Using the 1st and the 9th mafic intrusions of the Chajian ore district in the Hongqiling copper-nickel deposit as the research objects, we analyzed their petrochemical characteristics, trace elements and rare earth elements (REE), especially the geochemical characteristics of platinum group elements (PGE). The analysis of REE shows that the rocks are enriched in light REE and have weak negative europium (Eu) anomalies. PGE are concentrated in the rocks with high sulphide content, and the PGE content and the content of sulfide are positively related. The fractionation of PGE is obviously featured by enrichment of Rh, Pt and Pd. We supposed that the basic-ultrabasic rocks were formed under sulphur undersaturated conditions,from basaltic magma contaminated by crustal materials. The source of ore-forming materials of Chajian ore district is from the upper mantle and the main mechanism is deep liquation and injection.

Rayleigh distillation was introduced to modeling the metallogenic element enrichment process in the mafic-ultramafic intrusions outcropped in Panzhihua, Hongge, Baima, Taihe, etc. in the Panxi district, Sichuan Province, for their multi-scale nested rhythmic layering and iron concentration variation. Then, both their statistical and hypothetical models were constructed and their patterns were plotted to assess the mineral resources of iron, vanadium and titanium. Results show the similarity of the patterns of those in Panzhihua, Hongge, and Taihe, and for which the possible relation to their good crystallization differentiation in their originate magma and being favorable for ore bearing are suggested. On the other hand,  that in Baima is not consistent with the former possibly for its poor crystallization differentiation and poor ore bearing nature.

The granitoid rocks in Alatage, located in southern margin of central Tianshan plate in Daheishan area, are mainly composed of granodiorite, adamellite and porphyaceous granite. The granites are characterized by high SiO₂(66.29%-77.47%), high Na₂O+K₂O (6.75%-9.93%), high Al₂O₃ (10.97%-14.40%), and low Sr((28.78-153.00)×10^-6, averaging 99.23×10^-6) , and low TiO₂（0.09%-0.77%). The comprehensive analysis suggests that the granites are peraluminous calcalkalic series rocks(A/CNK=1.19-1.50); REE analysis shows that the averaged ∑REE is 362.04×10^-6, the ratios of LREE/HREE and (La/Yb)_N are 6.80-8.45，6.06-9.03 respectively. The REE distribution patterns show that the granites are enriched in LREE and depleted in Eu; the trace elements distribution patterns show that the granites are enriched in Rb, Th, K, Hf and Zr（LILE）except Ba, and depleted in Nb, Ta, P and Ti（HFSE）, especially depleted in Sr. Y-Nb, Y+ Nb-Rb and R₁-R₂ diagrams and Sr, Nd isotopic comprehensive analyses indicate a tectonic setting of post collision. The granites belong to granite complexes with mixed origin and multiple stages of intrusion.

The giant phenocryst adamellite is an important magmatism record of the Mongol Ocean plate in the late period of the Early Paleozoic Era. Their formation age and geochemical characteristics are significant to reveal the tectonic framework and evolution history of the Mongol Ocean plate at that period. The paper presents the zircon U-he U-Pb age of zircon of adamellite given is (454.3±3.8) Ma, belonging to the Late Ordovician. The geochemical data of granite show its high-K calc-alkaline nature. The granite is also characterized with high silicon, with SiO₂ being 69.82%-75.16%, Al₂O₃ 12.91%-14.49%, and Na₂O/K₂O 0.60%-0.77%, peraluminous, with aluminum saturation index being in the range of 1.11-1.22, and Mg^# index of 39-44. The total content of REE is 43.47×10^-6 -158.11×10^-6, δEu=0.26-0.49. The REE distribution pattern of adamellite is demonstrated by a significant negative Eu anomaly and a “swallow-type” shape. The spider diagrams of trace elements standardized by primitive mantle show apparent enrichment of Rb, Th, U, K, Zr, Hf, strong depletion of Ba, Sr, P, Ti and medium to slight depletion of Nb and Ta. The initial ¹⁴³Nd/¹⁴⁴Nd values are high (0.512 449-0.512 507), and the average value is 0.512 477. The ε_Nd(t) values are all positive (0.2-1.3). The characters of major elements, trace elements, and isotopes show that the giant phenocryst adamellite in the Southeast Mongolia was formed at an extensional geotectonic environment during the transitional period from syn-collision to post-orogenic tectonic systems. The extensional tectonics and the underplating of mantle-derived basic magmas are suggested to be the main dynamic mechanism to form the granite. Since the adamellite is the important magma record of the Mongol Ocean plate subduction in the early Paleozonic, the present research is helpful to reveal the tectonic evolution and the characters in the Palaeo-Mongolia Ocean plate area.

The rhyolites of the Early Cretaceous Shangkuli Formation in northern Daxing’anling belong to high-K calc-alkaline volcanic rock series characterized by rich-alkaline (K₂O+Na₂O>6.10%), high K₂O (3.25%-5.30%) and  high ratios of K₂O/Na₂O (0.67-2.48). These samples show strong enrichment in large ion lithophile elements (LILE) and in light rare earth elements (LREE). But the elements of Ba, Sr, Nb, P, and Ti are apparently depleted. The higher Th content and high Rb/Ba, Rb/Sr and Zr/Ba ratios of the rhyolites suggested a continental intraplate rifted setting related to the extension stage after the formation of Mongolia-Okhotsk orogenic belt. The current data indicate that the parental magma for rhyolites could be the products of the lower crust partial melting.

We present the U-Pb ages of the tuff zircons from the Dashigou and Sanlangpu Formations of the Xixiang Group at the northern margin of the Yangtze block, using the LA-ICP-MS dating analysis. Weighted mean ages are (789.0±4.4) Ma (MSWD=0.66) and (760.4±4.5) Ma (MSWD=0.43) respectively. According to existing data, the basal boundary age of the Xixiang Group should be ~820 Ma. Moreover, the Xixiang Group can be roughly compared with the Banxi Group and relevant strata in the regional scale, representing the early filling of the Neoproterozoic rift basin in the South China. Together with the underlying Sanhuashi Group, they represent the distinctive upper and lower tectonic-sedimentary circles, respectively. Combined with previous study results, it is indicated that there are three episodic magmatic activities during the Neoproterozoic epoch, with their peak ages being ~825 Ma, ~795 Ma, and ~760 Ma, respectively. The first two episodes, representing the commencing age and fully extensional age of the rift basin respectively, are more apparent than the third one, The volcaniclastic rocks from the Dashigou and Sanlangpu Formations reported represent the latter two episodic magmatic activities (~795 Ma and ~760 Ma) respectively, their geological significances should not be neglected, either because they are parts of the Neoproterozoic episodic magmatic activities or because they are closely related to the formation of the Neoproterozoic rift basin in the South China.

Our research area is located in Jining, the eastern section of the Khondalite belt in the western block of the North China craton, where the khondalite series is composed of garnet-biotite gneiss in the lower part and marble in the upper part. Several layers of felsic gneiss interbedded with thin marble layers are found, and the parental rock of the felsic gneiss is defined as feldsparthic sandstone by petrographical study, zircon characteristics and restoring the protolithic types. After LA-ICP-MS zircon U-Pb dating of the felsic gneiss, 72 zircon data are obtained from 70 zircon grains, among which the youngest detrital zircon data is (2 091±20) Ma that can represent the lower limit of felsic gneiss formation age; And the weighted average ²⁰⁷Pb/²⁰⁶Pb apparent age of the 19 metamorphic zircon concentrated between 1.8-1.9 Ga is (1 852±15) Ma（MSWD=0.7）, can represent the upper limit of deposition age of the original rock of the felsic gneiss. Based on the previous research results, we could conclude that in Jining area, marbles in the khondalite series were formed in the Paleoproterozoic Era between (1 852±15) Ma and (2 091±20) Ma, and underwent the regional metamorphism in (1 852±15) Ma. This suggests that marbles are the important component of the khondalite series; In the Khondalite belt across the western block of the North China craton, a large scale of granitic intrusion had existed in the source region of protolith of the khondalite series. However, there are different material source regions in every part of the belt; the protoliths of the khondalite series is not the in-situ deposition of fragmentary materials provided by the nearby Archean rocks, but alien tectonic rock sheet mingled with the nearby Archean rocks by Late Paleoproterozoic tectonic processes.

According to the numerical relationship between subsidence (or uplifting) rate and boundary fault strike-slip rate in pull-apart basin, the Cenozoic dextral strike-slip displacement of the middle portion of the Tan-Lu fault zone is indirectly calculated by restoring subsidence history of the Weibei sag which is bounded by the two branch faults of the Tan-Lu fault zone. The subsidence history restoration of four wells located at different structural units shows the sag experienced Early to Middle Paleogene fast subsidence, Late Paleogene uplifting and Neogene to present thermal subsidence,  and their averaged subsidence rate are  0.142 9 km/Ma, -0.072 8 km/Ma and 0.032 5 km/Ma respectively. Based on the analysis of the direction and velocity variation of the Pacific-Eurasia subduction, it is inferred the southwestward component of the westward compression stress between Pacific and Eurasia plate might be the main trigger for the dextral strike-slip movement of the Tan-Lu fault zone when the subduction direction changed from northwest to west at Middle Eocene (39.5 Ma). Given the strike-slip movement started at Middle Eocene and sustained to the present time, jointly considered with the subsidence and uplifting rate of the Weibei sag, the Cenozoic dextral strike-slip displacement of the middle Tan-Lu fault zone is calculated to be about 15 km.

As an ancient conifer, Elatides is of great significance for studying the composition of high-latitude vegetation in Northern Hemisphere during the Mesozoic Era. Some vegetative shoots and female cones of Elatides fossils with carbonaceous membrane were collected from the Lower Cretaceous, Jiuquan basin. Their gross morphology and wellpreserved features have been studied in detail. According to the features of vegetative shoots, leaf cuticular, pollen grains, female cones, cone scales and seeds, these fossils were identified as two species: Elatides harrisii Chow and Elatides curvifolia (Dunker) Nathorst. The prominent features of E. harrisii are spherical pollen grains, possessed small emulsion protrusions and smooth surface without ornamentation, being of longitudinal furrow in lateral view. The significant characteristics of E. curvifolia are their seed scale born in the base of ventral of cone scale and its tip Trifid with three ovules. These features are much similar to those of the extant Cunninghamia. It can be inferred that there may be a genetic relationship between Elatides and Cunninghamia. By researching the geological history and geographical distribution of Elatides, it is much comparable between the evolutional of the genus and the direction of the continental drift in Mesozoic, thus it can provide some paleontological evidence to the plate tectonics theory.

Late Pleistocene peat deposits are found in the two drilling cores located to the east and west of Shenyang City separately.The peat from the eastern drilling core was formed in the later Yumuya inter-galacial period and peat from the western core was formed after the Yumuya inter-galacial period. Pollen plant analyses of these two peat deposits show that the peat from the drilling core in the east contain mostly of pollen of deciduous broad-leaf plants indicative of warm and humid climate and those from the drilling core in the west contains pollen of angiosperm and minor needle and broad leaf plants in mountains rerpesentive of temperate and try climate. Quantative paleo-climate analysis suggests that the climate in the later Yumuya inter-galacial period was almost same as the present climate in Shenyang, but the climate after the Yumuya inter-galacial period was a little cooler than today in Shenyang.

Da’an City, in the west of Jilin Province, is one of the most severe regions that suffer soil salinization in Songnen Plain. Saline-sodic soil is the main type in this area, and the composition of soluble salts in the soil is similar to that in the environmental water. In order to study the concrete durability under such an exposure condition, experimental work on the effect of the multi-salt and dry-wet cycles on concrete performance was carried out. Water and four solutions of different concentration of multi-salt were prepared and used to simulate the concentration and the main types of the dissolved salts in the saline soil in Da’an region. The durability property of the concrete with five different mix proportions was evaluated through the tests of multi-salt and dry-wet cycles. The experimental results indicated that multi-salt had corrosive action on concrete under the condition of dry-wet cycles, and the higher the concentration of the multi-salt solution, the more severely the concrete was degraded. With the increasing times of dry-wet cycles, the mass of concrete and the dynamic elastic modulus of concrete showed a slight increasing at first, and then reduced after a certain number of dry-wet cycles. Air-entrained concrete and fly ash concrete were found have better behavior under such exposure condition, and much better improvement could be observed in the air-entrained concrete.

The basic method for optimal placement of monitoring points was established by using numerical simulation technology and fuzzy pattern recognition algorithm. Taking Lianziya dangerous rock body as an example and Ⅳ-Ⅳ’ profile as the optimal object, the sensitivity partition was studied based on the relationship between the sensitivity of monitoring variable (displacement) and the external interference factors and the amount of monitoring information. Then the optimal placement of monitoring points of this profile was designed. The results showed that it was better to locate the monitoring points at these places with an obvious displacement and a relatively high sensitivity, and install the deep displacement monitoring drilling through all the horizon-displacement-sensitivity area.

The shallow landslide is universal in loess plateau with no distribution law and no distortion evidence. There is no good method to forecast the frequent occurrence of shallow landslide, causing risk to the residence, traffic and river ecology. The assessment and prediction formula of shallow landslide under different rainfall was established by means of the infinite slope model combined with rainfall infiltration-strength reduction law and GIS technology. Then the build assessment model was used to predict the landslide occurrence at the effective rainfall of 30 mm, 50 mm, 100 mm and 200 mm in Xingfuchuan watershed, a first tributary of Yanhe River. In order to check  the applicability of the predict formula, it was compared with the popular assessment model of shallow landslide. The results are as follows: ①the instable and potentially instable shallow landslides are mainly distributed in both sides and source of the final class river, the stable and more stable region are mainly distributed in both sides of the first class river and highland surface; by comparing, the assessment results of SINMAP model are more consistent with the assessment results obtained by the predict formula built in this paper at the effective rainfall of 30 mm. ②according to the assessment results obtained by the predict formula built in this paper, the area of unstable region (safe factor，F_s<1) is gradually increased from 1.12% at the effective rainfall of 30 mm to 4.79% at the effective rainfall of 200 mm; on the contrary, and the stable region presents a decreasing trend. ③according to the distribution of shallow landslides had occurred, the proportion of the happened shallow landslides that located in the unstable region are significantly increased with the growth of effective rainfall, from 62% at the effective rainfall of 30 mm to 88% at the effective rainfall of 200 mm; and 64% of the happened shallow landslides are located in the unstable region according to the assessment result of SINMAP model. So the assessment model built in this paper is more accurate compared with the SINMAP model. Finally, advantages and disadvantages of the established prediction formula in shallow landslide assessment in loess plateau were discussed.

The groundwater in slope is one of the main factors that affect its stability. Draining water from slope can prevent the landslide from booting. The feasibility of applying compressed air to drain water in slope engineering by using basic theory model test was analyzed. It is concluded that this drainage method for slope is feasible and applicable to soil with pores radius above 5.0 μm，and the process of draining water with pressure air has the initial pressure. The drainage rate presents a proportional relation to the permeability coefficient and air pressure, and an inverse relation to the water head and pore radius. The preferential flow could be observed in bigger pores.

In order to evaluate the stability of gravel soil landslide based on the geological exploration information and experiment result, a multiple property regression model with one variable was created. Seven influencing factors such as the gravity of sliding body, angle and length of sliding surface, hydraulic gradient, immersion area, cohesion and internal friction angle were selected to conduct the regression analysis of stability coefficient and the significant research on these factors by using the model based on observed data of 14 engineering geological profiles of Guanjia landslide. The regression equation for calculating the stability coefficient of slopes was obtained, and Xinchang Xiashan landslide was taken to evaluate the accuracy of the model. Research results indicated that there was an obvious regression of the equation which was established according to the linear regression model. So the model can be used to calculate and analyze the stability of landslides. Factors that have significant influence on stability coefficient were determined by this model, and combined with the actual geological conditions, it was found that groundwater has a significant impact on the stability of landslides, which provides some useful references for the early-warning and prediction of landslide hazards and effective engineering control measures. The condition of Xinchang Xiashan landslide is between stability and instability,  intensive monitoring should be carried out during heavy rainfall periods.

Zigui County with prominent landslide hazard in Three Gorges Reservoir was taken as study area to conduct systematic research on landslide risk assessment. Based on the detailed analysis on landslide environmental factors, triggering factors, landslide inventory and the information of disaster bearing elements, landslide hazard was quantitatively assessed by using logistic regression model combined with statistical analysis method. The vulnerability of the population, buildings, lifeline engineering and land resources were calculated according to the landslide hazard intensity and the resistance ability of disaster bearing elements. Values attributed to disaster bearing elements were obtained by cost-value method for each element. Finally, landslide risk analysis considering life and economic costs were carried out through quantitative risk models in the studied area for next ten years. Highly risk areas of life and economic account for 1.11% and 2.71% respectively of the total studied area, and mainly distributed in the market town, school and enterprise residential quarters, transportation and construction land where there were dense population and prosperous economic value. Areas with moderate risk account for 13.21% and 20.66% separately, which were primary distributed in the rural residents and cultivated land. Low risk areas account for 85.68% and 76.63% individually mainly distributed in the area of treated geological hazard zone and little human activity of unutilized land and forest land. Combining with the field survey data, the risk analysis results were basically consistent with the status of local landslide disasters. It can be concluded that the critical areas, such as town, schools, enterprises, transport lines and so on, where damages are likely to be great require priority for mitigation actions.

The stability of the primary accumulations which is called Jiuzi collapse accumulation near Wanjiakouzi hydropower station in Xuanwei City, Yunnan Province wss analyzed by using Morgenstern-Price method and strength reduction method, taking into account four conditions such as the normal water level, the dropped level, and the two levels when earthquake occurred. The stability coefficient obtained by Morgenstern-Price method decreased with the storage level not only in the normal condition but also in the case of earthquake condition. But there is little change in the stability coefficient obtained by strength reduction method when water level varied. At the same water level, smaller stability coefficient could be achieved in earthquake condition. As to simple homogeneous soil slope, similar stability coefficient and slide surface may be achieved through strength reduction method and limit equilibrium method. And greater difference may occur when the slope is inhomogeneous. Morgenstern-Price method, assuming soil in the limit equilibrium, uses slices method in forces analysis, and it can not provide the slope displacement information, and several sliding surfaces should be assigned before calculation. In strength reduction method, the limit equilibrium state can be reached by reducing the strength parameters of the materials, and not only the soil stress-strain relations can be considered, but also the slope displacement information can be obtained. However, the strength reduction method is lack of a unified standard when slope reaches to the limit failure. Both methods can provide effective analysis and evaluation for slope stability.

It is hard to decide the initial slip force of normal friction damper. In order to solve this problem, a novel composite friction damping system (CFDS) is formed by connecting a nonlinear hard spring and a friction damper in series. When the earthquake intensity is smaller, the friction damper is in a state of adhesion, and nonlinear hard spring undergoes deformation to prevent the isolated layer from large drift. When the earthquake intensity is larger, the deformation of the hard spring keeps constant, while the friction damper is slip and friction damping occurs to dissipate seismic energy. The motion equations of base isolated structure with the proposed damping system are derived, and boundary conditions aimed at two different phases, stick and slip, of friction damper are pointed out. Then seismic response of the base isolated structure subjected to normal far-field earthquakes and near-fault pulse-like ones are studied. Compared with structures only installed with isolator devices, numerical simulation shows that CFDS can effectively suppress the horizontal motion of isolated layer. If the parameters of the damping system are proper, the interstorey drift and acceleration of the main structure are also reduced. Furthermore, the state of the friction damper in CFDS will switch between stick status and slip status. The influence of three parameters of the proposed damping system is also investigated in depth. It is pointed out that, since the seismic response change trend of the base isolated structure caused by the variation of CFDS parameters depends on earthquake type, optimal parameters of the CFDS is related to the peak ground acceleration and type of the earthquake, and the optimal parameters, which minimize both displacement and acceleration response of the superstructure, is not exist. So only when the proper control goal is given, the proper parameters of CFDS can be selected.

Although various methods can be used to determine hydraulic conductivity of aquifer, each method has faults that limit application, such as the results mainly dependent on the geometry and hydraulic boundaries of the streambed; The accurate value of coefficient C is difficult to obtain. The authors proposed a new method-Artificial Endocrine Network Model (AENM), and described its algorithm principle. In order to verify the validity of AENM, the traditional empirical formulas and AENM were applied in alluvial-pluvial fan front in North China Plain (NCP) to calculate hydraulic conductivity according to grain-size distribution and porosity. The results indicate that the Beyer formula was less accuracywith a relative error of 0.078-1.342, as to the  the Slichter method, the prediction accuracy rate was increased, but the forecasting error of extreme value was still larger with a relative error of 0.046-0.643; The prediction accuracy of AENM was higher, the relative error of 0.006-0.420. The AENM method has several advantageous over traditional methods which has not only higher calculation precision and stronger versatilitybut also could directly estimate vertical hydraulic conductivity without data transformation too long sentence to be revised. Therefore, the AENM method could be successfully used to study the hydrogeology parameter.

With regard to the numerical simulation of the effect of pumping water from big radiation well of groundwater reservoir of Tailan River, a sophisticated numerical simulation technology of radiation well using  the radiation well substructure method and substructure switch device was proposed based on the seepage analysis of big radiation well, and a finite element analysis of unsteady seepage field of groundwater with the influence of radiation well using the improved cutoff negative pressure method, incremental iteration method and the preconditioned conjugate gradients method of solving large sparse matrix was worked out. Using the 3-D visualization finite element seepage software platform GWSS, the numerical simulation of the tests of pumping water from radiation well of groundwater reservoir of Tailan River was carried out using this software platform. The study results show that for all observation wells the average absolute error of the calculation water level was 0.22 m, the maximum average absolute error of a single well water level was 0.40 m and a minimum value was 0.02 m, the calculation results and observation results of every observation well fitted well, therefore, the reliability of the program was verified. The radiation well substructure method can accurately simulate the seepage behavior and local seepage field of radiation well and it can be used for analysis of unsteady seepage field during pumping process of the radiation wells and to evaluate the effect of radiation well drainage.

To determine the distribution and variation of pH in micro-environment of fresh water/sediment systems with the presence of bioturbation, a real-time two-dimensional pH monitoring system based on planar optode was developed, using a modified sensor foil preparation method and a modified isograms acquisition and quantification method. The system was applied to monitor the spatial and temporal distribution of pH in a simulated freshwater/sediment microcosm with the presence of bioturbation. Compared to similar existing monitoring method, there were many advantages as wide pH-sensitive range (6.2-8.6), rapid response (<30 s), high precision, and good reversibility and stability, and it could be applied in the freshwater/sediment microcosm to show the spatial and temporal distribution of pH visually. According to the system monitoring, the spatial and temporal variation of pH in the sediment was minor, but the sediment has significant effects on the pH of overlying water. Significant and dynamic changes of pH distribution pattern in overlying water were observed, which was the combined effects of several actions, and these actions were all affected by the presence of bioturbation.

It is of practical significance to understand the soil salinity balance situation for the early warning of salinization and the guidance of agro-ecological environment regulation. Based on the four aspects of groundwater, climate, soil physical and chemical properties, an evaluating index system of the situation and application in semi-dry and semi-humid area has been set up and applied in low plain areas of Bohai Sea, as a typical zone( combined with a comprehensive index method). The results show that the area of “good” class accounted for 0.8% of the total, and the area of “fair”, “poor” and “bad” classes accounted 26.8%, 59.0% and 13.5% respectively, so it is hard to maintain the balance of soil salinity in this area. The evaluation result is coincident with the actual situation which show that the method is applicable in the low plain area of Bohai Sea.

The effect of dissolved organic matter (DOM) on Pb leaching in Pb-contaminated soil treated by freeze-thaw action was investigated with the laboratory simulation experiments. The results showed that physiochemical properties of soil and chemical speciation of Pb were significantly changed by freezethaw action; DOM could significantly facilitate Pb leaching in freeze-thaw soil compared with non freeze-thaw soil. The leaching influences of DOM on Pb in Pb-contaminated soil were closely related to the soil type, soil contamination time and contamination degree. The leaching influence of DOM on Pb in brown soil was greater than that of in black soil,and increased with the time and degree of soil contaminated by Pb increasing. The leaching influences of DOM on Pb in Pb-contaminated soil were also closely related to the mass concentration, properties and component of DOM. The leaching amount of Pb was improved by the increase of DOM mass concentration, the lower pH of DOM and the low-molecular-weight hydrophilic fraction of DOM facilitated the leaching of Pb from in soil.

Arid area of wetlands as a special landscape type in the arid zone, it is one of the most productive ecosystems and plays an important role in region eco-environment conversation and local water cycles. So, its expansion or deduction is bound to impact the regional ecological environment. Bosten basin is one of the largest lake wetland distribution areas in Xinjiang arid area.We used Landsat series data as the main data source, achieved 3 times remote sensing wetlands mapping (1990, 2000, 2010). And then, we analyzed Bosten basin wetlands distribution status, explored spatial and temporal changes process of regional wetlands and dynamic characteristics. The results showed that, the area of wetlands in Bosten basin has been decreasied in recent decades. The total area of wetland has reduced 16.24% in past 20 years. But, the rate of deduction is slowing down and the different type of wetlands changes process is different. The details are as follows. In 1990-2000, river wetlands and lake wetland performance increasing trend, and reed wetland was decreasing. In 2000-2010, river wetland, reed wetland and lake wetland area were all in shrinking. Through the coupled relationship analysis between the wetland change and the factor of the regional ecological environment showed that: wetlands changes in the Bosten lake region are mainly impact by human activities in short-term.

Magnetic methods provide a fast tool for delineation of industrial pollution. 58 soil samples were collected for magnetic properties and heavy metal (Cd，Cr，Cu，Mn，Pb，V，Zn，Fe) mass fraction analysis in Jiayuguan City, Northwest of China. The results revealed that the magnetic properties of soil samples are predominated by low-coercivity magnetite, pseudo single domain (PSD)-multi domain (MD) in size, and characterized by high content of ferrimagnetic fraction and coarse particle size. Additional, as the distance increasing to steal manufactory, concentration of ferrimagnetic fraction is decreasing and the particle size is smaller. The high positive consistency is shown between heavy metal materials (Cd，Cr，Cu，Mn，Pb，V，Zn，Fe) and ferrimagnetic fraction, and low negative with magnetic particle size due to presenting nearly same particle size in magnetic fraction between pollution material and soil. So, the magnetic parameters which are related to content of magnetic fraction, just as  χ_lf, ARM, and SIRM, which can be used as an indicator of heavy metal pollution.

The western Sichuan Plateau is located on the transitional zone of plateau climate and monsoon climate. Climatic characteristics of this region are very important for understanding of the Tibetan Plateau impacting on the surrounding climate.¹⁴C dating, stratigraphic correlation and grain size vs. age model were used to calculate ages for all sampling stratigraphic levels. Multi-proxy including grain size, color, magnetic susceptibility, and carbonate content analysis of Zhangla loess section at western Sichuan Plateau revealed a detailed history of climate changes since 104 ka B.P. The long-term trend of increasing grain size, middle grain sizes are 17.6 and 17.7 μm in MIS(marine isotope stage)3 and 4, may be explained in part by a rapid uplift of the Tibetan Plateau events. The climate showed suborbital scale fluctuations similarity to millennial-scale climatic changes recorded in Nanjing stalagmite. The strength of H(heinrich)2 significantly higher than H1. It may indicate that the climate system at high latitudes in the Northern Hemisphere had played an important role. There were two distinct weakening aridification recorded in MIS3, during 28-31 ka and 42-45 ka. They may suggest that the climate system also controlled by factors at low latitudes.

According to the travel time data of P-arrivals recorded by seismic networks array along the Changbai Mountain and the permanent stations of Jilin Province, the 3D P-wave velocity structure of the crust and upper mantle down to 40 km depth beneath Changbai volcano and its adjacent areas (39°N-45°N, 122°E-130°E) is reconstructed by seismic tomography method. The result  shows that earthquake occurrence and distribution is focused on fault and other geological structures. We prove the existence of magma systems and guess that magma systems is located in the southwest of the crater, a depth of 10 to 40 km by three-dimension high resolution P-wave velocity structure in the crust and upper mantle. The presence and distribution of magma systems in the crust provides important evidence for further explaining and understanding of volcano activity.

Based on the anisotropic effective model of fracture medium, the authors analyzed velocities of compressional and shear waves, the variations of elastic stiffness modulus with respect to the fracture density, the fracture aspect ratio and the fluid properties filled in the pore. We also examined the applicability and the accuracy of Hudson model and its Pade approximation and the Liu fracture model, and focused on the effects on elastic modulus and velocities of the compressional and shear waves of the geometric parameters of the fracture pore, fracture porosity and the fluid filled in it. On the basis of the Pade approximation of Hudson fracture model, we proved that Pade approximation is suitable for higher fracture density and larger fracture aspect. The simulation results indicate that when the fracture density is less than 0.1,the Liu fracture model and Hudson second order approximation lead to consistent elastic response; Liu fracture model and Pade approximation are applicable to the cases when fracture density is less than 0.2; for the cases of fracture density larger than 0.2, the Liu model shows more reasonable result. Furthermore, in the water saturated and the dry fracture medium, the fracture aspect presents more significant effects on the the Liu model.

Full waveform inversion (FWI) can reconstruct underground velocity while utilizing the kinematic and dynamic information of pre-stack seismic data, which could reveal detail information of the structure and lithology under complex geological background. However, huge calculating amount and storage space requirements confine the development of full waveform inversion. A combined method of L-BFGS algorithm and simultaneous sources technology is applied to ameliorate this problem during frequency multi-scale full waveform inversion. First we carry out velocity inversion based on the Marmousi model. It can be obviously found that the memory spending has been improved considerably in the process of calculation, and the fitting error between the final inversion result and true Marmousi model is as small as 0.095 9. Meanwhile, single shot forward modeling 384 times takes about 32 640 seconds when using 10 frequency bands, while simultaneous sources which contain 384 shots forward modeling one time needs only about 700 seconds. Then we conduct research on the anti-noise ability based on the high-speed wedge model. The signal to noise ratio of original seismic data is 11.147 3 dB, while the signal to noise ratio of the seismic data obtained from forward modeling based on inversion velocity model is 22.251 8 dB. Finally we conduct research on inversing the medium with velocity perturbation based on the thrust fault model. The final inversion model is very clear and very satisfied with the real model with velocity perturbation characteristics, and the fitting error between them is only 0.036 0. Numerical simulation experiment result indicates that the inversion precision of this method is higher enough, and the memory spending is less, which could significantly increase calculation efficiency. What is more, this method has good anti-noise ability, and could inverse the medium with velocity perturbation characteristics.

Spectral decomposition technique as an interpretative processing technology has been paid extensive attention by many geological and geophysical researchers. The effectively frequency division display function of seismic signals for oil gas detection has also become a focus point. The authors propose a spectrum decomposition technique of Wigner bispectrum diagonal slice with an improved kernel function based on high time-frequency resolution of the Wigner higher order spectrum. According to the advantages and disadvantages of the exponential and the cone-shaped kernel functions, the new improved kernel function is given. Then the kernel function filtering method in fuzzy fields is used to suppress the cross-terms of Wigner bispectrum diagonal slice and the center point of the ambiguity function in Wigner bispectrum diagonal slice is corrected. The numerical simulation shows that the new function can suppress the cross-terms of time-delay axis. Finally, the effectiveness of  new technique is verified by indicating the presence of oil and gas area in 20 Hz profile, and in accord with well.

The perfectly matched layer (PML) absorbing boundary condition has proven to be a very efficient method for the numerical forward modeling of elastic wave equation to absorb both body waves and surface waves. But in some cases such as grazing incidence and the free surface in narrow domain the classical discrete PML method suffers from some serious problems. The complex frequency-shifted PML which uses the complex frequency-shifted stretch function in the coordinate transformation can efficiently improve the PML absorbing performance. We derived a recursive convolution method for implementing complex frequency-shifted PML and carried out the numerical simulation employing the staggered-grid higher-order finite-difference method based on the first-order partial differential wave equation. The results show that the complex frequency-shifted PML based on recursive convolution method can largely improve the absorbing effects in difficult cases. And its implementation is convenient because of the un-split variable. The cost of the calculation is not increase because of the recursion when convolution is computed. The memory storage is also similar to that of the classical PML.

Leaf Area Index(LAI) is a key structural and functional biophysical variable in the study of ecological environment research, also, an important path of energy exchange of terrestrial vegetation. Through the study on radiative transfer theory of vegetation from multi-angular, hyper-spectral data, LAI is estimated by bidirectional reflectance distribution function(BRDF). According to discrete anisotropic radiative transfer(DART) model, the zenith angle and azimuth are discretized to 61 direction combinations, look-up-table(LUT) of LAI inversion which is suitable for multi-angular and  hyper-spectral data is constructed. Then, PROBA/CHRIS data in Changbai Mountain area is selected, pre-processed, and matched with LUT based on least squares principle, LAI in the research area is retrieved. Subsequently, the sensitive factors of LAI to BRDF, of 470 nm and 700 nm bands, in the 61 discrete directions, are evaluated. With LAI values increasing, BRDF value of 490 nm wavelength increases firstly and decreases successively, and BRDF value of 700 nm wavelength decreases; BRDF value decreases when zenith angle increases, and reaches minimum near the zenith.

As a data synthesis method, Weights of Evidence (WofE) model has been widely used in mineral resource quantitative assessment. On the basis of fuzzy weights of evidence, a new weight of evidence method is developed, where layer construction and data integration are based on vector data and vector method. The complete process of modeling is then given combined with a case study, in which the buffer of mineral deposits is taken as training layer, the unique geological units are obtained as evaluation objects by spatial overlaying of all evidential variable layers, and weights of each evidence are then calculated, at last probability map and delineated target can be gotten based on geological objects by weights integration of all evidential layers. Different from raster-based WofE, vector-based WofE model keeps the natural boundary of a geological feature used as geological units which have explicit geological meanings, and can improve the accuracy of posterior probability; Instead of the rectangular regions resulting from regular division, circular regions are used to represent known ore occurrences, which improves the known ore occurrences representatio. A case study shows that average area error are 0.26% and 6% when prediction unit size is equal and not equal with an integer multiple of initial grid size respectively; When prediction unit size is of an integer multiple of initial grid size, average calculation error for deposits is 4.78%. It can be concluded that Prediction unit partition method based on the weight of evidence of geologic units thought better accuracy than the method based on raster or regular grid. Thus the obtained posterior probability distribution based on vector prediction unit division method is more reliable than grid-based method.