Abstract:Abstract：Regional geochemical exploration in China changed greatly from 1999 to 2009. Regional geochemical exploration methods and techniques as well as mineral resources potential assessment have been deliberately studied and remarkable progress has been achieved under the guidance of geochemical theory. The principle of regional geochemical exploration methods and techniques developed aims at demonstrating the primary state of geochemical distribution in the highest degree. Selection of sampling media suitable for landscape and surficial geochemical condition is the key problem for regional geochemical survey. Samples collected should reflect the information of geology and mineralization, and hence weathered material of rocks is usually selected as sampling media. Efforts have also been made to collect the same material over the whole country. The established methods for mineral resources potential assessment and quantitative mineralization prognosis based on the theory of geochemical zoning have promoted the exploration geochemistry from pure methods to a theoretical level for steering mineral prospecting. The main achievements are as follows: systematic methods and techniques of national regional geochemical exploration have been established; analytical process and its quality are strictly controlled; Several geochemical atlases have been published based on accurate geochemical data, which can exactly reveal geological setting and anomalous characteristics; regional geochemical data and its information have been studied profoundly and applied widely; the methodology system and working procedure from regional, reconnaissance to detailed exploration have been established for resource survey, assessment and prognosis. Regional geochemical exploration has been supporting mineral survey in China for a long period, acting as a forerunner of all geological work. It is certain that regional geochemical data will play an important role in new discovery, new understanding and new viewpoints of basic geology, mineralization regularity, and great geological events with the compilation of new geochemical maps covering various regions and the whole country. All this will have great influence on exploration geochemistry and geological work in China.

Abstract:Abstract：Hydro-physicochemical properties and element concentrations of rivers constitute key indicators related to water functions. Chemical flux through river to sea has important impact on marine ecosystem. This paper presents pH values, electric conductivities and soluble concentrations of major and trace elements in river water sampled at the lower position or estuaries of 33 rivers. It is demonstrated that pH values, electric conductivities and soluble concentrations of major and trace elements in most rivers of northern China are much higher than those in rivers of southern China, which is consistent with climate change from north to south. The soluble concentrations of major elements in river water are associated with the zoning of soil type and soil chemical distribution pattern from north to south. However, anomalous content of major elements and physicochemical indexes in some rivers may be influenced by the mixture of sea water with fresh water. It is found that trace element concentrations in some rivers are anomalous in comparison with the concentrations in other rivers of the same region. Such a phenomenon may be attributed to (1) special geological and geochemical background of drainage areas; and (2) anthropogenic activity and pollution. It is inferred that the lower concentrations of soluble Na, Ca, K, Zn, Se in flood season are caused by dilution under higher precipitation, whereas the higher concentration of Al, REE, Fe and some other elements may be the consequence of containing lots of micro-particulates and colloids derived from soil through surface current.

Abstract:Abstract：To improve the analytical methods of Te by ICPMS, the authors made the detection limit of Te down to 0.005μg.g-1. For the South China regional geochemical mapping program, about 100 RGNR samples from each 1∶50 000 map sheet were combined into a single sample. The resulting 5 244 composite samples were subsequently determined by ICPMS. 3 giant and 2 regional Te geochemical anomalies were delineated in South China. Te anomalies in east Yunnan and west Guangxi are related to the distribution of limestone. Te anomalies in Chenzhou of Hunan Province, Shaoguan of Guangdong Province, Xianggelila of Yunnan Province, Daye of Hubei Province and Tongling of Anhui Province are related to copper polymetallic deposits.

Abstract:Abstract：Geochemical parameters of top and deep soils as well as geochemical baseline and background were calculated based on multi-purpose regional geochemical survey covering Yangtze River-Huaihe River basin of Anhui Province. The concentrations of most elements in top soils are mainly controlled by their concentrations in deep soils. The concentrations of some elements in different soil layers are apparently different. Soil formation processes and anthropogenic activities have had remarkable impact on the distribution of elemental concentrations in soils. It is demonstrated that soil parent material usually has significant influence on geochemical baseline. Geochemical baselines of soils derived from the same parent materials have the tendency to vary in different geographical units. Therefore calculation of soil geochemical baseline should consider spatial variation. These results can be widely used in eco-geochemistry and related multi-discipline research.

Abstract:Abstract：According to field investigation, it is found that the black rock series of Shuigoukou Formation in Shanyang area of the Qinling Mountains is made up of micritic limestone，carbonaceous argillite, claystone, carbonaceous siliceous argillite, carbonaceous limestone and silicalite. Phosphatic nodule and barite are commonly seen in these rocks. The abundances of rare earth elements and some trace elements such as V，Ni，Co，U，Th in the black rock series were measured using ICP-MS method. Some conclusions have been reached： 1) The average concentrations of ore-forming elements （such as V，Mo，Ni，Ba，Pb，Zn，U，Ag，Cu，Cd，Tl，Bi and Cr）are several times to dozen times higher than their crustal abundances）, showing that they are rich in the rock series, especially in silicolites and argilloid. Higher content of trace elements and rare earth elements is closely related to phosphorus，TOC and barium. 2）Different concentrations of rare earth elements are connected with different types of rock. The black rock series is usually of the LREE-enriched type. 3) The samples are characterized by slight or intermediate negative Ce anomalies (δCe=0.40～1.00) and distinct positive Eu anomalies, exclusively with high δEu (>2.1). 4）The ratios of U/Th display a large variation from 0.31 to 28.7, the ratios of w (V) /w (V +Ni) ( 0.51～1) and w (Ni) /w (Co) (4.8～49) are relatively high，the ratios of w (Ce) /w (La) (0.68～1.89) are normal, and the average rate of?w (Co) /w (Zn) is 0.21. According to a comparison of these related parameters of REE and trace elements with the available data in the references and the La/Yb- Ce/La and La/Yb - REE diagrams, it is suggested that the black rock series of Shuigoukou Formation was formed in the environment of a dry, anoxic and profundal to semi-profundal faulted depression sea basin belonging to a passive continental margin, with the action of hydrothermal fluids.

Abstract:Abstract：According to geochemical characteristics in combination with thermal evolution, there exist mainly three sets of source rocks in Sikeshu depression of Junggar basin, namely Jurassic (Badaowan Formation, Sangonghe Formation and Xishanyao Formation), Cretaceous and Paleogene. The Badaowan Formation source rocks which contain high abundance of organic matter of primarily Ⅲ and Ⅱ2 type have fairly good hydrocarbon-generation potential. The Sangonghe Formation source rocks have poor condition of hydrocarbon generation in that they have low abundance of organic matter and inferior type of kerogen. The organic matter abundance in source rocks of Xishanyao Formation is relatively high, but its hydrocarbon-generation potential is not ideal owing to relatively small thickness and poorer type of organic matter. The Cretaceous source rocks in Sikeshu depression have maximum thickness of 300m, but the condition of hydrocarbon generation is not favarable due to the lower maturity. Paleogene source rocks with high abundance of organic matter and Type Ⅱ organic matter have poor hydrocarbon-generation potential because of lower maturity. Through oil-source rocks correlation and quantitative identification of mixed oil, it is concluded that the crude oil in Chepaizi area was mainly derived from the Jurassic source rock in Sikeshu depression and mixed with the immature crude oil from the Cretaceous source, but the hydrocarbon generation of the Paleogene source rock is very little due to no distribution of the source kitchen. It is inferred that coal-formed oil dissolved the biomarker-rich Cretaceous bitumen of relatively low thermal maturity, and overprinting occurred during oil migration.

Abstract:Abstract：The Hangshaping large-size W-Mo polymetallic ore deposit lies in the Nanling metallogenic belt. The authros chose the skarn as well as wall rocks（limestone and marble）and ?granite porphyry related to the skarn to conduct component analysis. The result shows that the major elements (Fe, Al, Mg and Si) migrated between the granite porphyry and the skarn, and the content of SiO2 shows linear descending relationship with the content of MgO, MnO, CaO and Fe2O3+FeO in the skarn. The skarn is enriched in LREE and depleted in HREE, with obvious Eu negative anomalies. The granite porphyry has the same REE distribution patterns as the skarn. The precise Re-Os dating of the molybdenite from skarn-type ore yielded an ore-forming age of 158.4±1.3 Ma. which is the same as the age of the granite porphyry, suggesting their relationship in petrogenesis. The poorly-developed Ce anomalies in skarn rocks imply that the fluids for the formation of skarn were mainly derived from the magma and mixed with meteoric water. Combined with the geochemical characteristics of different rocks, intense differentiation of LREE and HREE and Eu negative anomalies, the authors infer that the skarn in the Huangshaping ore deposit was formed by fluid metasomatism.

Abstract:Abstract： Western Henan is an important base area of China’s gold, silver, molybdenum, lead, zinc and polymetallic resources. In recent years, new ore deposits have been discovered in succession. Geologists’ estimations of resources quantities in this area are quite different from each other. On the basis of geochemical blocks theory and through regional geochemical data processing and calculation, the authors delimited the boundaries of western Henan gold geochemical blocks and calculated their areas, amounts of metals available and mineralization rates according to different levels of gold, molybdenum content. Using calculating method to predict the amount of gold resources in western Henan, the authors obtained 2 445 t for total gold amount and 11.1 million tons for molybdenum. At present, proved reserves account for a very small proportion in forecast resources. Compared with anomaly ore-concentrated areas of the same level in the world, the proved resources of this area are obviously low. Therefore, it has considerable resource potential.

Abstract:Abstract：The early Yanshanian granites related to tungsten and tin deposits in Nanling region have been considered to be biotite granite, monzogranite, albite granite etc. However, microscope and electron microprobe analyzes of the granite related to tungsten mineralization in Yaogangxian, Shizhuyuan, Xitian, Dengfuxian, Limu and Meiziwo show that all the feldspars of the granite consist of K-feldspar and albite (An<5), which suggests that the name should be alkali feldspar granite. The albite of greisen inclusions in the alkali feldspar shows the character An<3. There is no obvious vertical regular variation or zoning of the compositions of the albite and granite within the depth range of 1000m. On the contrary, the plagioclases of the granite inclusions (xenoliths), some granite porphyry dykes, giant batholiths, and Triassic and Paleozoic monzogranite or granodiorite have a wide range of An value of 0～93, belonging to oligoclase, andesine or even basic plagioclase. The alkali-feldspar granite that contains two kinds of alkali feldspar was usually formed from the rich-volatile (Li-F) magma, with the extensive development of liquid immiscibility at the top of the granite, which caused the enrichment and mineralization of W, Sn, Bi, Mo in the hydrothermal-magma. The An value of the albite in alkali-feldspar granite could be used as an indicator for evaluating granite in search for W-Sn mineralization, because the value is obvious lower than that of barren granite.

Abstract:Abstract：This paper deals mainly with sedimentary media environment of Late Triassic epoch in the middle part of western Ordos Basin through identifying the corresponding relationships between trace element compositions and sedimentary media environment on the basis of analytical results of some special trace elements such as Sr, Cu, Ba, U, Ti, V and Ni which are sensitive to sedimentary media environment. The results of the study show that the sedimentary media environment of Late Triassic epoch from Chang-9 to Chang-7 was warm humid climate in general and tended to become increasingly warm and humid in upward direction, indicating the brackish water phase of the freshwater environment with a slight increase in salinity of Chang-7. The redox condition from Chang-9 to Chang-8 was normal, while that of Chang-7 became anoxic. The vertical variation of water column stratification is not obvious from Chang-9 to Chang-7.

Abstract:Abstracts：The mixed siliciclastics and carbonate sedimentary system is developed extensively in eastern Qiangtang basin. Based on previous research results, the authors studied the diamictite and diamictic system, terrigenous clastic rock and carbonate rock by means of regional geological material analysis and inner sample analysis. The results show that the study area is characterized by interactive sediments of terrigenous clastic rock and carbonate rock at the microscopic level, called “mixed rock”, and that in the macroscopic performance there exists the mixed sequence composed of terrigenous clastic rock, carbonate rock and mixed rock. Mixed sedimentation resulted from facies mixing with minor source mixing and event mutation, which formed the sedimentary system of shore, carbonate gentle slope and tidal flat-lagoon. Combined with the tectonic setting and guided by the sedimentary principles, this paper proposes a mixed sedimentation model for the eastern part of the Qiangtang basin in Tibet.

Abstract:Abstract：Using seismic data, drilling core, well logs and paleontology data, the authors studied the sequence stratigraphy and sedimentary facies of Taizhou Formation in Baiju sag of Subei basin, identified three sequence boundaries in Taizhou Formation and divided Taizhou Formation into 2 third-order sequences (SQ1, SQ2) and 4 system tracts. According to sedimentary signatures, the authors recognized three facies types in Taizhou Formation, i.e., braided-river delta, meandering-river delta and lacustrine facies, which can be subdivided into 8 types of sedimentary subfacies and 17 types of sedimentary microfacies. SQ1 was deposited during the initial faulting period of the basin, characterized by the development of braided-river delta. In the period of the low-stand system tracts of SQ2, the extension of basin was increased, and the area of lake was enlarged, and meandering-river delta was developed. In the period of the transgressive system tracts and high-stand system tracts of SQ2, the development of basin transformed the faulting period into the shrinking period, the area of lake was the biggest and semi-deep and deep lake subfacies were developed in the period of the transgressive system tracts of SQ2, the water-level was declined slightly and shallow-shore lake facies was developed in the period of the high-stand system tracts of SQ2. The main source rocks were developed in the transgressive system tracts of SQ2 which also served as good capping formation. The sand body reservoirs composed of underwater distributary channels of braided-river delta front, underwater distributary channels and sheet sand of meandering-river delta front were developed in the low-stand system tracts of SQ1-SQ2, sandy beach and sandy bar of shallow-shore lake in the high-stand system tracts of SQ2, which constitute the potential areas for oil and gas.

Abstract:Abstract：Based on identifying the sequence surface and analyzing the sequence stratigraphy of outcrops and well data, this paper regularized the stratigraphic classification of different facies from Permian to middle Triassic in south Guizhou and middle Guangxi. The Permian-middle Triassic strata in the study area can be divided into 2 super sequences and 19 third-order sequences. Taking super sequence system tracts as the mapping units, the authors drew the tectonic-sequence lithofacies paleogeographic map, which shows depositional facies distribution pattern of different stages from Permian to middle Triassic. This paper analyzed the filling processes at three evolution stages from Permian to middle Triassic in the study area, i.e., stage of rift valley basin of passive margin, stage of rift valley basin of back-arc, stage of foreland basin. On such a basis, a model of sedimentary filling and dynamic evolution during the process of relative sea level change was constructed, which shows that the lowstand period was the alternate basin-upheaval stage, the transgression period was the formation stage of alternate platform-basin, and the highstand period was the typical sedimentary pattern of alternate platform-basin during the period of the passive continental margin rift basin and the backarc rift basin from Permian to middle Triassic in south Guizhou and middle Guangxi. From middle Triassic, affected by Indosinian movement, the sedimentary pattern of alternate platform-basin was ended and transformed into the sedimentation of turbidite of foreland basin.

Abstract:Abstract：Provenance analysis is of great significance in determining the sediment source, parent rock properties, sediment transport distance, and even sedimentation and tectonic evolution of the whole basin. Heavy mineral assemblages, light mineral assemblages, REE distribution pattern and palaeocurrent direction were systemically analyzed in this paper. Six main provenances in the Oligocene period of western Qaidam Basin were determined, i.e., eastern Altun provenance, western Altun provenance, Aral provenance, Tomorlog provenance, Qimantag-Dongqaishan provenance, and Wanxi-Gansen provenance. Provenance characteristics significantly control sediment characteristics. The sediment transport distance from western Altun provenance was short. Pyroclasts supply was evidently controlled by seasonal floods, so it was very unstable and always developed near-source steep type fan delta and near-shore subaqueous fan sediments. Sediments from the rest of the provenance were transported for a long distance, with the maximum transport distance being about 190 Km; pyroclasts supply was stable, and thus developed braided delta sediments of far-source mild slope type. Due to the influences of several provenances, the sedimentary characteristics were obviously different.

Abstract:Abstract：The Putaohua reservoir in 1st Member of Yaojia Formation within Sanzhao depression is the main reservoir, oil layer and also the important target reservoir for increasing production in the study area. The distribution of the reservoir has intimate relationship with the source, and hence the source system analysis is an important task in petroleum exploration. Based on core observation and description as well as a comprehensive study of the analytical data, the authors analyzed the source direction in terms of heavy mineral assemblage, ZTR index variation characteristics, regional distribution of mudstone color and features of sand distribution. The source system for Putaohua reservoir in 1st Member of Yaojia Formation within Sanzhao depression was determined, and the affected area and intensity variations of each source were comprehensively analyzed and determined. The results have laid a good foundation for precise study of the sedimentary system and prediction of the reservoir.

Abstract:Abstract：The Weijia tungsten deposit is another large-size tungsten deposit discovered recently during the new round of prospective survey for mineral resources on the northern margin of the Nanling Mountains. Based on a discussion on the metallogenic geological background, the authors studied the geological characteristics of the ore deposit. The spatial distribution of the ore body is controlled by the basement structure, lithologic character, Xianglinpu anticline, Xianglinpu granite porphyry and the concealed rock body resulting from the NE-trending intrusion of the Tongshanling granite porphyry. The secondary emplacement of the magma caused the secondary mineralization. The ore deposit is of porphyry-skarn type. In this paper, ore-prospecting criteria are pointed out, and ore-search prospects as well as direction for further work are analyzed, which is of some guiding significance for ore-prospecting work in the future.

Abstract:Abstract：The Nannihu-Sandaozhuang molybdenum deposit is the largest porphyry-skarn type deposit in eastern Qinling region. This paper reports new LA-ICP-MS zircon U-Pb age data of granitoids (including granitic veins) and ICP-MS molybdenite Re-Os isotopic age data of the samples from the mining area. The obtained formation ages of granitoids are 145.2±1.5 ~ 146.7±1.2Ma, and the model ages of 5 molybdenite samples from stockwork in the Nannihu mining area and 5 molybdenite samples from disseminated skarn in the Sandaozhuang mining area are 143.4±2.0 ~ 146.5±2.3Ma with isochron age of 146.0±1.1Ma. These new geochronological data show explicitly that the granitoids and ores were formed simultaneously, suggesting their genetic relationship. Furthermore, these new data have confirmed the existence of magma-thermal event at about 158Ma revealed by previous dating work, and also for the first time revealed that the eastern Qinling area once underwent another magma-thermal event at about 175Ma. The published weighted average age data are of distinct deviation from the real intrusive age of the Nannihu magmatic body, which results from 1) nonhomogeneous origin of zircons in magmatic rock and 2) unrepresentative dating of zircon group.

Abstract:Abstract：Based on a study of regional metallogenic regularity, this paper summarizes the prospecting criteria for the southern metallogenic belt in the Mian-Lue-Ning triangle area as follows: ① strata composed of Proterozoic basement metamorphic volcanic rocks and adjacent clastic rock and carbonate rocks; ② well-developed NE-NNE trending faults; ③ areas where fractures are filled with intermediate-basic veins; ④ geochemical anomaly areas of such elements as Au, Ag, Cu and Zn. The authors analyzed the metallogenic conditions of the study area and considered that the study area had favorable conditions in search for gold deposits related to fractures. First, using the IP intermediate gradient method, the authors quickly and accurately delineated two parallel NE-trending anomaly zones (No.Ⅰ, No. Ⅱ) which had high polarizability and low resistivity, and then disposed two polarization pole-dipole array sounding and soil geochemical profiles perpendicular to the anomaly zones. Combining geological data with interpretation, the authors predicted that the two anomaly zones were caused by two concealed ore-bearing fractures. Using adit engineering under the No.Ⅰ anomaly zone, the authors found a quartz vein type gold ore body which contained polymetallic sulfides. It is thus inferred that there exists a larger gold ore body under the No. Ⅱ anomaly zone, which has stronger and greater anomaly intensity than No.Ⅰ.

Abstract:Abstract：This paper deals with the mineral-bearing characteristics of magmatite complex rocks in the Tianshan metallogenic belt. 4 mineral-bearing complex rock belts and 5 deposit genetic types have been determined. The research on metallogenic specialization shows the following characteristics: 1) Magmatite iron phosphate is controlled by the deep fracture at the edge of the platform; 2) The host rock is mainly of the alkaline ferruginous-mafic rocks suite; 3) The major and trace elements in host rack are obviously inconsistent with each other; 4) The paragenesis of rock types mainly shows the association relationships of biotite diopsidite, pyroxenite, alkaline gabbro, plagioclase and carbonate rock; 5) Mineral paragenesis mainly shows the characteristics of diopside + apatite + magnetite + biotite, plagioclase + apatite + magnetite + soda-zoisite and pyroxene + apatite + magnetite. The elements paregenesis shows notable correlation of P, Fe, Ti, V and REE. Based on prognostic research, the authors delineated 9 ore perspective areas with ore-forming conditions.

Abstract:Abstract：Guizhou depression has experienced three stages of tectonic evolution, i.e., the early Proto-Tethys rift basin and the late orogenic fold，ancient Tethys rift basin stage，and the Neo-Tethys oroganic transformation phase．With the large-scale transgression in the early Devonian，there developed platform sag and slope facies dark shale and coal-bearing coast swamp facies framework in this area，which mainly included Lower Devonian Tangding Formation black shale，Middle Devonian Luofu Formation black shale and lower Carboniferous Yanguan Formation black shale．Researches have shown that the upper Paleozoic marine shale，characterized by high abundance of organic matter，good types and high-over- mature stage of evolution，has favorable conditions for shale gas．Up to date，Upper Paleozoic shale has been found in many gas shows in Guizhong depression，which has similar geological condition to typical shale gas basins in eastern United States (Appalachian，Ford Voss and Michigan basin). According to the analogy method，the amount of Upper Paleozoic shale gas resources is preliminarily estimated to be about 12.34x 1012m3 in the depression，which indicates that the area had huge shale gas resource potential．

Abstract:Abstract：The airborne lidar is a new kind of remote sensing technology for collecting accurate three-dimensional coordinates on the surface by laser. In order to investigate and monitor the landslide of Three Gorges Reservoir Area, the authors obtained the high-precision DEM through the acquisition and processing of the airborne lidar data. On such a basis, the authors made the airborne lidar landslide investigation and dynamic monitoring test qualitatively and quantitatively. The resutls indicate that the lidar hill shade map can express micro-topography, and the lidar slope and surface roughness maps can provide precise micro-geomorphic feature parameters. In addition, deformation trends and characteristics of the landslide within a certain period can be detected and accurate deformation can be measured by multi-phase airborne lidar data.

Abstract:Abstract：In this paper, the current status of groundwater quality study in China is reviewed briefly firstly. In view of the disadvantages of traditional methods, a set of means for regional groundwater evaluation based on Arcgis system, which can not only process mass samples but also map the assessment results automatically, is put forward. The outputs of this method preserve the very poor point which was likely to be overlooked in the past. The evaluation results based on more than 3000 groundwater samples collected from 1035 wells in Beijing Plain show that from the shallow part to the depth, the quality of groundwater in Beijing tends to become better. The analytical results show that the main excessive components of the groundwater samples are total hardness, TDS , Mn, NH-4, Fe, F-, NO-3 and NO-2. The total area belonging to class IV and V is 3649 km2, 2258 km2 and 737 km2 respectively for shallow, middle and deep groundwater. Also, the comparative results show that on the whole the groundwater quality in the wet period is slightly worse than that in the dry period within Beijing Plain.

Abstract:Abstract：Dali County is an important agricultural area in Guanzhong Basin, and is one of economically active areas in Shaanxi Province. However, water resource shortage has become a factor restricting further economical development. Based on collecting some information and surveying the hydrogeological conditions, the authors evaluated the water quality of the shallow groundwater by conducting groundwater test and using the single norm method. Three areas of safe groundwater resource were found. This paper evaluated the safe area groundwater resource quantity in Dali County by adopting the information collection and numerical simulation technique. At last, the exploitation potential of the safe area groundwater resource was computed. According to the fact of the safe groundwater resource shortage, the safe water supply in Dali County was zoned. The result indicates that the exploitation potential of the safe area groundwater resource in Dali County is up to 1687×104m3/a. This conclusion has important significance for solving the contradiction between the supply and the need of the safe groundwater resource.

Abstract:Abstract：This paper aims to clarify the degree, pollution sources and the plant availability of the soil heavy metal pollution along the Xiaoqing River so as to provide the basis for the scientific management of the heavy metal pollution in this area. It is found that along the basin of the Xiaoqing River, the main heavy metal pollutants are As, Cd, Cr and Ni. According to the Nemerow pollution index evaluation, the area without heavy metal pollution in the study area is 1822.1 km2, while the soil area contaminated by heavy metals has reached 880.5 km2, accounting for 67.42% and 32.58% of the total area, respectively. The both sides of the Xiaoqing River from Beiyuan Town to Huashan Town of the Jinan City are heavily polluted areas. An analysis of sources of heavy metals in soil shows that that the dry and wet atmospheric deposition obviously from irrigation and fertilization are the main sources of heavy metal pollution. The bioavailability evaluation of the heavy metals was carried out by the method of sequential extraction, and the result shows that the active state of the heavy metal Cd is as high as 56.17%, with a strong capability of mobilization and migration, which constitutes the most harmful pollution factor affecting the ecological environment in this area. In addition, the contents of active state of As, Cd, Cr, Pb and other heavy metals are significantly constrained by pH and Corg content, and in areas with low pH and high Corg content, great importance should be attached to the pollution problem of As and Cd.

Abstract:Abstract：The Pearl River Delta Economic Zone, which lies in the central south of Guangdong Province and borders on the South China Sea, has experienced strong land-sea interaction and active neotectonism as well as obvious erosion，and is characterized by wide distribution of Quaternary sediments and a variety of landform types. It is a transitional zone and a sensitive belt of geological environment. The unique geological environment must have caused corresponding geological environment problems. Based on current survey and past research findings, the authors have summarized the main factors controlling geological environment, such as geomorpohologic landscape, neotectonism, change of sea surface and evolution of Quaternary sedimentation. The mainly problems of geological environment and calamity geology in the Pearl River Delta are put forward，which include earthquake and crustal stability，surface deformation in soft soil area，karst collapse，and coast anomalous change with the superimposition of sea level rising. From the angle of geological environment, some corresponding countermeasures are proposed.

Abstract:Abstract：Through the systematic sampling along the section of Tianluoshan Site in Yuyao City, Zhejiang Province in combination with other researches，the authors consider that the Hemudu Culture probably had been damaged by tsunami or storm tide calamities, as evidenced by the researches using such means as stratigraphic correlation, paleomagnetism, micropaleontology and palynological study and 14C dating.