On Jiamusi-Mongolia block, the contact relationship of Late Paleozoic and related strata contains abundant tectonic information. We systematically combed these data and discussed the formation and evolution of Jiamusi-Mongolia block. The angle unconformities can be found under Xibiehe Formation on the southern margin of Jiamusi-Mongolia block, Woduhe Formation on the northern margin, and Heitai Formation on the eastern margin. These angle unconformities under the Late Silurian-Early Devonian strata reveal a significant tectonic movement, indicating that the Jiamusi-Mongolia block was formed in Late Silurian-Early Devonian. The contact relationship between the strata of Devonian, Carboniferous and Permian are all conformable, which manifests a stable subsidence period during Devonian-Permian on the Jiamusi-Mongolia block. The parallel unconformities under the bottom of the Late Permian Linxi Formation and under the bottom of the Early Triassic Lujiatun Formation are the significant mark of the collision and collage between Jiamusi-Mongolia block and North China plate. The parallel unconformity surface, the above Molasse Formation, and the stratigraphic sequence change from marine to continent during Middle-Late Permian indicate a foreland basin sedimentary environment of Linxi Formation. The angle unconformity under the bottom of Lujiatun Formation and the characteristics of Molasse Formation in conglomerate indicate a continuous progressive orogeny. The angle unconformity under the bottom of Late Triassic Dajianggang Formation indicates the end of the orogeny and the development of Jiamusi-Mongolia block as an independent block.

A research was conducted on the differences between tight sandstones and normal sandstones of the oil charging dynamics through the analysis of dynamic characteristics and its effects on oil migration. The tight oil migration distance and accumulation mechanism were also discussed. In addition, we analyzed the effect of mudstone barriers and fractures on oil accumulation in tight sandstones, and concluded that:in tight sandstones, mudstone barriers can block oil migration, and lead to the blank-zones near the barriers; the sand bodies directly contacted with fractures are the most possible targets for oil accumulation.

For a basin with low degree exploration, looking for the high-quality hydrocarbon source rocks is significant for the choice of exploration direction. Based on a large amount of test and analysis data, we took Hari sag in Yingen-Ejinaqi basin as the research object, and studied the petrological and geochemical characteristics of the high-quality source rocks in Yingen Formation, the source of organic matter, and their forming conditions. The results reveal that the source rocks are micritic dolomites and dolomitic mudstones. The average value of w(TOC) of the source rock is 5.62%, extremely high abundance of organic matters. The organic matter is type I-type Ⅱ₁, belonging to sapropel, or partial sapropel. Although the overall maturity is relatively low, the bottom of the source rocks has reached the mature thermal evolution stage with high potential of hydrocarbon generation. The source of organic matter is the mixed of higher plants and aquatic organisms. The Pr/Ph value of high quality source rocks is 0.19-0.27, which represents a strong reducing sedimentary environment; the gammacerane index is 0.30-0.54, and such high content of gammacerane shows its high salinity of sedimentary environment. High productivity generated by algae blooming and anoxic environment are the two key conditions to form high-quality hydrocarbon source rocks.

Less than 10 km away from each other,Duhuangling and Jiusangou deposits are two typical high-sulfidation gold deposits in Yanbian. The fluid inclusions in quartz from alteration rocks and ores were analyzed by using micro thermometry, Raman microprobe,and noble gas isotope to reveal the origin and evolution of the ore-forming fluids. The fluid inclusions in the alteration stage and the early mineralization stage are mainly gas-liquid two-phase inclusions with major gases of CO₂ and N₂. The occurrence of a few high-salinity (33.4%-48.1%), high-temperature (410-460℃) fluid inclusions represent the mixing of a epithermal mineralization fluids with the porphyry system at depth. The fluid inclusions indicate that the homogenization temperature of the main mineralization stage is from 90℃ to 330℃, the salinity is 0.4%-44.9%,and the composition is dominated by H₂O and a small amount of CO₂. The coexistence of liquid-,vapor-rich inclusions and halite-bearing multiphase inclusions suggests a boiling event. These inclusions were trapped at depth between 100 and 500 m, representing the fluids related to the epithermal mineralization at Duhuangling and Jiusangou. The fluid inclusions in pyrite are characterized by the ³He/⁴He ratio of 0.009 6-0.020 6 Ra, ²⁰Ne/²²Ne ratio of 9.734-9.987, ²¹Ne/²²Ne ratio of 0.030 9-0.040 6, and ⁴⁰Ar/³⁶Ar ratio of 1 302.4-4 433.6. Combined with the stable isotope data,these ratios suggest that the early ore-forming fluid was of high temperature and high oxidized magmatic gas carrying Au, Ag, Cu and other ore-forming elements,the mixing of the fluid in the crust led to the boiling process during the main ore-forming stage, and the liquid was dominated later by low temperature and low salinity atmospheric water.

Wafang Pb-Zn deposit is located in the Xiong'er-Waifang Mountains of the southern margin of the North China craton. The ore bodies are existed in the upper Jidanping Formation of Xiong'er Group, and the ore minerals are pyrite, galena, sphalerite and little chalcopyrite, limonite, and hematite. The hydrothermal ore-forming processes are divided into three stages:quartz-pyrite stage (early stage), quartz-polymetal stage (middle stage), and quartz-carbonate vein stage (late stage). The fluid inclusions in quartz and calcite of ores are NaCl-H₂O two-phase, NaCl-CO₂-H₂O three-phase,and pure gas. The homogeneous temperatures the two-phase inclusions in the three stages are 150-260℃,150-230℃ and 110-160℃, respectively. The average salinity w(NaCl) in the three stages are 12.22%, 8.55%, 6.29%,respectively. The δ¹³C_VPDB and δ¹⁸O_SMOW of the calcites of the middle stage are high with the mean of -7.34‰ and 15.56‰, respectively, showing the characteristics of freshwater carbonate. The δ¹³C_VPDB and δ¹⁸O_SMOW of the late stage are at an average of -3.05‰ and 2.21‰,respectively. The δ³⁴S values of sulfides in the early and middle stages are 2.747‰-7.737‰ and -11.187‰-7.286‰, respectively. We conclude that the ore-forming fluid in the early and middle stages was metamorphic fluid, which was related to the metamorphic dehydration of the Meso-Neoproterozoic slab subduction during Mesozoic continental collision between Yangtze and North China craton, then mixed with meteoric water in the late stage. The S isotope indicates that sulfur was derived from Meso-Neoproterozoic sedimentary stratigraphy by the reduction of marine sulfate. In the middle and late stages, negative δ³⁴S values occurred due to the mixing with meteoric waters. The characteristics of geology and ore-forming fluid in Wafang Pb-Zn deposit are similar to orogenic deposits.

The Bizigou Cu deposit is located in the field of "Hu-Bi" type Cu ore district in Zhongtiao mountain in the southern edge of the North China craton, and it was formed through multiple mineralization events. The orebodies are consistent with the attitude of stratum, and are bedded in the Bizigou Formation and Yuyuanxia Formation. Molybdenite and chalcopyrite occur disseminated in the molybdenite-bearing calcite-quartz veins. Re-Os molybdenite model ages fall in the range from (1 539±26) to (1 616±26) Ma with an isochron age of (1 522±180) Ma (MSWD=9.6) and a weighted mean model age of (1 577±31) Ma (MSWD=5.5), suggesting its hydrothermal vein mineralization formation in the Mesoproterozoic. In the hydrothermal mineralization of the Bizigou deposit,three mineralization events were identified:Paleoproterozoic disseminated mineralization, Paleoproterozoic vein-type mineralization, and Mesoproterozoic vein-type mineralization. This study indicates the existence of a Mesoproterozoic hydrothermal Cu mineralization event in the Bizigou and Zhongtiao Mountain region combining with the existing data.

Yichun area is an important lead-zinc ore district in Heilongjiang Province, where the metallogenic geological conditions of skarn lead-zinc mine are superior. Based on the probe into the metallogenic conditions, 15 evidence layers from geological, geophysical, geochemical and remote sensing are optimized and constructed through spatial analysis of the GIS system. Three class metallogenic prospect areas have been divided and seventy-seven prospective areas of lead zinc have been circled finally by the evidence weight model. 81.08% of the known deposits (points) are located in the prospective areas, indicating the reliability of the prediction results. Among them,fifty-four prospective areas have not found lead-zinc deposit and they have the similar metallogenic conditions with known deposits. Thus, big attention should be paid to these areas for a prospecting breakthrough.

The Panling ore concentration area is a typical paleoproterozoic sedimentary basin and a multi-metal ore-concentrated area, located in the zone of Caohekou-Caohecheng-Heiyu, also in the middle section of Liaoning-Jilin rift. The Beidalazi rock developed in the Early Cretaceous and the Gaoliduntai rock developed in Paleoproterozoic are closely related with the mineralization in this ore-concentrated area. The weighted average of the zircon SHRIMP U-Pb age of the Beidalazi rock is (123.9±2.2) Ma, and the weighted average of the zircon SHRIMP U-Pb age of the Gaoliduntai rock is (1 872±13) Ma. The ε_Hf(0) value of the Beidalazi rock is negative, and the ε_Hf (t) is (-16.86——10.95), that indicate its shell material domination when the Beidalazi rock formed. The single stage Hf model age (T_DM) is 1 339 Ma, and the two-stage Hf model age (T_DM^C) is 2 043 Ma. The ε_Hf(0) value of Gaoliduntai rock is negative, and the ε_Hf(t) is 0.29-4.64, that indicate the shell material domination when the Gaoliduntai rock formed. The single stage Hf model age (T_DM) is 2 171 Ma, and the two-stage Hf model age (T_DM^C) is 2 355 Ma. The geochemical results show that:The Beidalazi rock is of high-K calc-alkaline series and highly differentiated aluminous I-type granite, and it is a thickened and molten product of the lower crust with a serious magma contamination in the Late Mesozoic continental margin magmatic arc environment resulted from the Early Cretaceous subduction of the paleo Pacific plate; The magmatic activity directly led to the mineralization of copper, lead, zinc and molybdenum etc. in Panling area. While the Gaoliduntai rock is a kind of low potassium magmatite (tholeiitic) and highly differentiated aluminous I-type granite caused by the melting of the basaltic melt to heat the crust to melt, and it may have the contribution of mantle material invasion induced by a series of faults (including inter-layer fractures) to control the mineralization and distribution of the ore veins.

The LA-ICP-MS zircon U-Pb dating and geochemical data were obtained for the volcanic rocks of the Suzy Formation in the central region of Inner Mongolia, so as to reveal the tectonic nature of the middle section of the northern margin of North China plate in Early Permian. The zircons from the volcanic rocks in the Suzy Formation are euhedral-subhedral in shape, and display fine-scale oscillatory zoning with high Th/U ratios (0.61-1.06), implying their magmatic origin. The LA-ICP-MS zircon U-Pb age data indicate that the andesite from the Suzy Formation was formed in the Early Permian (279.0±2.1 Ma). The geochemical data indicate that the andesites belong chemically to medium-K calc-alkaline series, poor in SiO₂(49.0%-55.2%) and HFSEs, rich in Al₂O₃ (15.7%-17.8%), Mg (Mg^#=49.8-67.0), and LILEs, and display low REE abundance and flat REE pattern, similar to those from an island arc. Combined with its characteristics of High-Mg andesite, we consider that its primary magma were mainly derived from partial melting of the depleted mantle wedge alterated by the subduction of slab-derived fluid. It can be concluded that the andesite from Suzy Formation was formed under a tectonic subduction when the Paleo-Asian Ocean was not closed.

The Lower Ordovician carbonate sedimentation of Lunshan Formation in Jurong area is composed of an open platform and a deep-water shelf. The sequences 1 and 2, two transgression processes, are both composed of the low stand system and the transgressive system tracts. The relative sea-level lifting curves of Lushan Formation can be drawn based on the paleo-salinity and paleo-bathymetric curves reflected by the values of δ¹³C, Sr/Ba, 1 000Sr/Ca and V/Ni, combined with the sedimentary environment change and system tract features. The Level I sea-level relative lifting curve reflects that Lunshan Formation underwent a transgression. The Level Ⅱ sea-level curve shows that the sea-level fluctuated frequently. A fluctuation included two sea-level relative rises and one fall. The composition of oxygen and carbon isotope in Lunshan Formation was less affected by the late diagenesis, and it retained basically the original marine isotope composition. The δ¹³C value falls between -0.8‰ and 2.3‰, and the mean is 0.45‰. The δ¹⁸O value falls between -14.4‰ and -9.3‰ and the mean is -10.2‰, mainly in the range of -10.0‰——9.0‰. The Z values calculated from δ¹³C and δ¹⁸O are all greater than 120, which reflects that the carbonate in Lunshan Formation formed in a marine environment.

In order to research the mechanism of the landslides with accumulation layer-bedrock contact surface, which are widely distributed in Langao County, Shaanxi Province, the authors summarized the basic characteristics of the landslides through field investigation, laboratory test and numerical simulation, and mathematical statistics by taking the Zushimiao landslide as an example. The formation mechanism of landslide with accumulation layer-bedrock contact surface is concluded as follows:1) The landslides with accumulation layer-bedrock contact surface are mainly developed in the slopes with 20°-40° gradient and their underlying bedrock fragmented, mostly the shallow surface landslides; 2) The internal friction angle of gravel soil and the accumulation layer-bedrock contact surface decreases with the increasing of the water content, and the contact surface is the weak structural plane of the slope deformation; 3) The increase of fine particles reduces the internal friction angle of the contact surface, and the smaller the particle diameter is, the smaller the internal friction angle, and the greater the decrease in the saturated state; 4) The strength decrease caused by the small particle soil at the interface between accumulation layer and bedrock and the saturation of slip zone soil caused by the change of hydro-geological conditions are the main predisposing factors of the Zushimiao landslide. The research results have certain guiding significance for revealing the formation mechanism of landslide and the prevention and control of geological hazards.

As a key link in the current urban development, the scientific site selecting and planning of a new urban area needs to be based on the clear engineering geological conditions.Taking Tongchuan region as an example,according to the latest geological structure and landform evolution, we determined the types of landform and divided the the sedimentary structures into eolian deposition, fluvial and pluvial deposition, and complex deposition in respect of the Quaternary sediments. According to the results of collapsibility tests, the depth more than 22 m of the loess in the study area is without self-weight collapsibility, and the depth more than 24 m is without collapsibility. Based on the calculation of the collapsibility amount, the study area is graded into non-collapsible areas, level 2, level 3, and level 4 collapsible zone. There are 4 zones (low mountainous, loess platform, loess hilly, andvalley terrace) and 8 sub-zones. On the basis, we summarized the engineering characteristics of each engineering geological area. Of them, the low mountainous areas and loess hilly areas are not suitable for construction; while the level 2 collapsible of high and low loess plateau, part of valley terrace areas after a foundation treatment,and level 3-4 collapse of high and low loess plateaus are suitable for construction. The research results provide some guidance and reference for future urban site selection and project construction planning under similar geological conditions in Loess Plateau.

The group landslide disasters are described as landslide group and landslide zone in the previous studies of geological disasters, and the connotation of landslide group or landslide zone is fuzzy, limited, and discursive. In most instances, the two terminologies are merely abbreviations of multiple landslides, and lack of practical significance for the research of geological disasters. We revised the concept of landslide group and enriched the connotation of "landslide group" through taking the structure background into consideration. The evaluation method of landslide group has taken shape under the guidance of the revised landslide group concept. Thereby, it becomes possible to compare the internal individual landslide in the same group and landslide groups within the new tectonic activity area. Under the guidance of "landslide group", a "landslide group" assessment method is proposed. The "landslide group" evaluation method mainly includes the following aspects:local tectonic style as well as its formation mechanism; the spatial evolution of local tectonic and geological disasters; comparison of the internal individual landslides in the same "landslide group". Based on the study, "landslide group" space-time evolution model is established to provide the basis for predicting future landslide hazards.

In recent years, the conceptual hydrological model has been widely used in hydrological forecasting. In order to explore the adaptability of SIMHYD model in the Songhua River basin, and provide the basis for flood control and reservoir control in flood season, we selected the Shihuiyao section located in the upper Nenjiang and the Baishan section located in the upstream of the second Songhua River to simulate the daily runoff of flood period. The results show that there are regional differences of the application of the model in the Songhua River basin:For the Shihuiyao collection area, the Nash-Sutcliffe coefficient is 0.501 in calibration period, and 0.158 in verification period, poor adaptability of the model; For Baishan collection area, the Nash-Sutcliffe coefficient is 0.777 in calibration period, and 0.729 in verification period, good adaptability of the model. There is a big error for the simulation of flood peaks, which is mainly caused by that the model does not take into account the uneven space-time distribution of runoff generation and the calculation process of river concentration.

Land subsidence is a kind of slowly changing geological disaster caused by the reduction of ground elevation. In order to evaluate the degree of land subsidence and traffic load, we used PS-InSAR technique to obtain the spatial character of the land subsidence in the east of Beijing area, and evaluated the traffic load level of the ground subsidence based on the information of the subway station and the road node by using data field model. Further, we used the factor contribution weight method to achieve the land subsidence traffic load degree zoning map of Beijing. The results show that the land subsidence information can be extracted by PS-InSAR, and the maximum subsidence reaches 77.69 mm/a. The high level of regional land subsidence traffic load is mainly distributed in the northern and central regions of Chaoyang; while the area of low level regional land subsidence traffic load is mainly located far away from the city's main traffic roads and subway lines.

The fast extension of traffic network results in the fragmentation of ecological landscape due to the division, isolation and damage and largely transforms the landscape process and pattern in urbanizing area. In this paper, the Xi'an metropolitan zone was analyzed as a case study. Based on remote image and employing spatial analysis method, the spatial structure of road network and the evolution of landscape pattern were evaluated. Furthermore, the influence of road network on landscape pattern was analyzed in term of spatial perspective. The results show as follows:1) From 1985 to 2015, the road network of Xi'an metropolitan zone had been improved and make complicated constantly. Basically, except for Yangling and Yanliang district, the spatial index of road network tends to gradually decrease away from the downtown of Xi'an, and that tends to be higher in the east than in the west. 2) With the improvement of urbanization, the landscape characteristics in whole were more fragmented, diversified and complicated in Xi'an metropolitan zone. Specifically, the areas of orchard, forest,and built-up land were expanding and that caused the increase of the degree of landscape aggregation whilst the fragmentation degree of farmland, water body and beach land has increased seriously. 3) During recent three decades, with the increasing construction of traffic road in whole region, the road network of Xi'an metropolitan area is gradually improved; While the landscape dominance is decreased, the fragmentation degree is increased. In addition, the influences of the road network on different land types were varied due to its development degree:In road developed area, the built-up land is large, regular in shape, and aggregated, but the forest area is less, that scattered and more fragmented; While in road poor area, the degree of aggregation of the forest patches is high, but the farmland, water body and beach land are more fragmented, and their shape is irregular.

Upward continuation of gravity field is considered to be a stable and convergence process, but downward continuation is not. This paper presents a new method of downward continuation of gravity field. Firstly, the gravity field and its vertical first-order derivatives are continued upward to different height. Secondly, the authors derive with the stable downward continuation based on multistep method of Adams-Bashforth formula of third-order of the differential equation. Finally, the method is applied to the synthetic model data and the real data. Compared with the classical downward continuation methods which are the Fourier transform method and integral-iteration method, the synthetic results show that the new method, which is Adams-Bashforth formula of third-order, is more stable, less edge effect, the depth of downward continuation is 5 intervals, the relative error of the downward result and the real value is smaller, and the result is more accurate. The method is applied to the measured airborne gravity data in Canada, and the results obtained are valid and accurate. Small sources are identified and delineated.

The distributing properties of vertical resistivity and susceptibility of soils around an iron and steel plant have been obtained for pollution assessment using DC depth sounding, environmental magnetism and mineralogy. The study shows that soil resistivity values decrease gradually, while susceptibility and heavy metal content increase from the bottom to the surface of the contaminated soils, indicating a correspondence between the degree of soil pollution and the crude steel output each year and the vehicle numbers of Wuhan City. Through the analyses on hysteresis loop, thermal magnetic curve, and SEM/EDX mineralogy for the contaminated samples, the mineral components of polluted samples are predominantly magnetite and hematite, existing in pseudo-single domain (PSD), obviously different from the magnetic grain formed during pedogenic process in aspect of feature and ingredient. Because the electric and magnetic properties of soil have good indication to pollution degree, the study of soil electric and magnetic properties can be used to assess soil pollution, and the combined use of these two properties can also greatly improve the resolution of soil pollution assessment.

In this study, we developed three-dimension forward modeling for surface-borehole transient electromagnetic (TEM) by using staggered-grid finite difference method, and obtained transient electromagnetic response characteristics from different borehole positions for a conductive thin plate. The Helmholtz function is discreted by staggered-grid finite difference method in frequency domain, then the abnormal-field is quickly processed using MUMPS package. Background Green function can be efficiently computed by equivalent fictitious square overlay method and virtual interface method, which extending the transmitter and receiver to anywhere in full space. The cosine-transformation was performed for borehole transient electromagnetic response in any position, then the mentioned algorithm was validated by three-dimension model. We designed two three-dimension conductive models, one is the homogeneous half-space, the other is an embedded conductive plate, to get the three-dimension distribution of vertical magnetic field in the time domain, and then we analyzed the influence of the conductive body on transient electromagnetic response. It is shown that the solution of three-dimension transient electromagnetic in this study is comparable to those of the predecessors'. The existence of a conductive plate influences mainly on borehole TEM near the plate body and through the conductive thin plate; and TEM symbol change occurs in the middle time channels near the abnormal body. The proposed research provides a technical method for qualitative interpretation of surface-borehole transient electromagnetic data, and lays the foundation for three-dimension inversion of surface-borehole transient electromagnetic

In seismic data analysis, it is a general case that seismic signal always displays nonstationary characteristics because of wave-attenuation effects. By time-frequency decomposition methods, such as short-time Fourier transform, wavelet transform, and empirical mode decomposition, seismic data can be decomposed into a set of stationary components, which are easier to be processed and interpreted. Following this idea, the paper introduces a new method named local mean decomposition (LMD). The LMD method can decompose seismic data into several product functions (PFs). Compared with the intrinsic mode functions (IMFs) by the EMD method, the PFs preserves more details and the mode mixing effect is weaker. The applications to model data and field data show that the LMD method can make the decomposition more properly, and capture the local character of seismic data from different time points.

We collected earthquakes with local magnitude above 1.0 and travel time data in Shandong area from the year 2009 to 2016, and calculated one-dimension seismic velocity model. The process mainly included three steps:1)Initial model:to fit the travel time data and analyze the reduced travel time curve, eventually to get the initial model and its span; 2) Best model:to relocate the selected events of all possible models based on Hyposat software, according to the RMS and geophysical background, to get the best model of P phase and the possible model of S phase through adding a reasonable variable to theoretical seismic velocity ratio, then to relocate events of all models according to the RMS, and finally to reveal the best model; 3) Model test:to test the best model by using the test of natural earthquake event, blast event, horizontal epicenter comparison of three location methods, depth comparison of four location methods, HypoDD epicenter comparison of Rushan and Changdao earthquake clusters, and ultimately to get the best model. The one-dimension seismic velocity model in Shandong is:v_P1=6.13 km/s, v_P2=6.88 km/s, v_P3=7.93 km/s, H₁=22 km, H₂=33 km, v_S1=3.54 km/s, v_S2=3.95 km/s, v_S3=4.46 km/s. Besides, the location accuracy of nonlinear algorithm such as simplex generally is less dependent on the seismic velocity model; whereas the linear iterative positioning method based on the Geiger algorithm is more dependent on the seismic velocity model.

In high precision geophysical prospecting gravimetry, high accurate plane position and elevation are needed. The projection distortion caused by Gauss-Kruger projection zoning and elevation is too big to meet the precision requirement for control survey in long distance profile of geophysical prospecting. The abscissa projection distortion and elevation influence of Gauss projection can be reduced by the method of oblique axial deformation of the ellipsoid Gauss projection with least squares method, coordinating with the theory of ellipsoid transformation and the theory of Gauss-Kruger. Taking the long-distance profile of Mohe-Hohhot as an example, we obtained the position of plane and elevation using GPS fast static measurement. The distance between measuring points is 1 km in this example. The accuracy obtained by this method is high. The maximum plane precision is 67.87 mm/km, and the maximum height accuracy is 53.039 mm/km. It can be concluded that our method has an advantage in problem solving in geophysical prospecting of long-distance profiles.