Abstract:Abstract：This paper deals with the dynamic sources responsible for tremendous changes of the lithosphere in eastern China. It seems that the flow of mantle caused by Rayleigh-Taylor instability is the main tectonic force. As Rayleigh-Taylor instability exists only in intermediate continent, mushroom cloud mantle can occur only in such intermediate continents as eastern China.

Abstract:Abstract：The Cangshuipu Group is developed between the Lengjiaxi Group and Banxi Group in Yiyang area of Hunan Province, located in the middle part of the Jiangnan orogenic belt. It is considered that the study of its position in chronostratigraphic column can solve the problem of the initiation of the Jiangnan orogenic belt. The authors obtained a SHRIMP zircon U-Pb age of 821±13 Ma from the volcanic rocks in the Cangshuipu Group. This age suggests that the volcanic rocks represent a volcanic event before the Wuling movement (820 Ma), which was related to the initiation of the Wuling movement, with the volcanic tuff of this volcanic event being the product of the same tectonic movement as the volcanic tuff in the Lengjiaxi Group.

Abstract:Abstract：The formation age of Jiaoyuqiao Group, i.e., the metamorphic rocks in the northern margin of Gangdise, is still in controversy. High resolution LA-ICP-MS in situ U-Pb analysis was conducted for the intercalation of garnet-bearing green schist in marbles of upper Jiayuqiao Group at Bajian Village, Baxoi County, Tibet, and an upper intercept age of 566±27 Ma was obtained. This result cinfines the formation age of the Jiaoyuqiao Group to late Sinian. Combined with related data, the authors hold that there existed a large continental margin rift in the northern margin of Gangdise in late Sinian-Cambrian period.

Abstract:Abstract：LA-ICP-MS U-Pb dating of zircons from subdacitic porphyry samples yielded a weighted mean 206Pb/238U age of 174.6±1.5 Ma (MSWD=0.7) in the Dabaoshan polymetallic deposit of northern Guangdong Province. Re-Os dating of three molybdenite samples from porphyry and skarn ores yielded consistent model ages from 163.2±2.3 Ma to 165.2±2.4 Ma. These ages are consistent with the molybdenite Re-Os model age (164.7±3.0 Ma) measured by Mao et al. for the stratiform Cu-Pb-Zn ore body, and they can yield a weighted mean of 164.0±2.5 Ma (MSWD=0.16). These data imply that Mo-W and Cu-Pb-Zn mineralization in the ore district are products of the same mineralization event, which coincides closely with the event of Mo-polymetallic mineralization elsewhere in the Nanling region and corresponds to the second episode of Mesozoic metallogenesis in South China. Geological data, together with stable isotopic data of fluid inclusions (δ18O =－3.75‰～7.0‰, δD =－50.7‰～－56.1‰) and ore sulfides (δ34S =－2.00‰～3.00‰), suggest that the Dabaoshan ore deposit is a magmtic hydrothermal ore deposit associated with the granodioritic porphyry and the subdacitic porphyry. This is different from previous studies which argue for the existence of superimposition of multiple mineralization events comprising Caledonian exhalative deposition and Yanshanian superimposed mineralization or two Yanshanian mineralization stages. Based on geochemical diagrams of Y+Nb-Rb and Rb/30-Hf-Ta×3 in combination with previous studies, the authors suggest that the Dabaoshan polymetallic deposit is related to post-collisional lithosphere extension in the Nanling region of South China.

Abstract:Abstract：On the basis of regional geologic survey that the authors have carried out for a long time in Jiangxi Province, this paper puts emphasis on the investigation of lithostratigraphic sequence and the subdivision and correlation of ages of the epimetamorphic strata of Meso-Neoproterozoic folded basement before Sinian as well as three suites of complex strata such as the late period of Qingbaikou System and Nanhua System through the collection and study of the relevant geological data in combination with the utilization of the methods of correlation and analysis of structure, lithologic assemblages, key horizon succession and isotopic dating data. The results show that the differences of the stratigraphic lithology between Jiangnan continental margin, South China oceanic basin and metamorphic basement of Huaiyu island arc is apparent, suggesting that the age of the former may be later than that of the latter. On such a basis, this paper puts forward a new opinion on the main characteristics of the arc-basin system of the early Neoproterozoic period and the rifting system of the late period of Qingbaikou System, In addition, their development and evolution are also discussed.

Abstract:Abstract：The sedimentary facies of 3rd Member of Lower Jurassic Badaowan Formation in Shixi area of Junggar Basin was previously regarded as meandering river delta. The authors consider it to be the product of tractive current under fairly strong hydrodynamic conditions, as evidenced by the texture, sedimentary structure and distribution characteristics of the sandstone. Its sedimentary environment belongs to the braided fluvial delta. Based on a synthetic study of its sedimentary characteristics, the authors identified 2 subfacies and 5 microfacies in the study area, which include the braided delta distributary channel, braided delta flood plain swamp, braided delta subaqueous distributary channel, tributary bay, and mouth bar. The distribution characteristics and evolution processes of sedimentary facies are inferred as follows: during the early stage the water level fell, the study area developed braided delta front; in the middle stage the water level continued falling, the study area developed braided delta plain; in the late stage the water level rose, and the sediments became thinning. The northwest Halaalate Mountain, Delun Mountain and Zhayier Mountain located in the margin of the study area constituted the main material sources.

Abstract:Abstract：In order to determine sedimentary characteristics and model of the Late Early Silurian strata, the authors comprehensively studied outcrop sedimentary features and a large number of core and well logging data of the Silurian Xiaoheba Formation. The results show that the late Early Silurian transitional sedimentary system group and marine sedimentary system group are developed in southeastern Sichuan Province and include three kinds of sedimentary facies and lots of sub-facies as well as micro-facies. Delta deposits are developed in southeast Sichuan - western Hunan area close to Xuefeng Mountain uplift. Carbonate platform deposits are developed in southern Sichuan - northern Guizhou area. Shelf deposits are developed in the Yibin - Chongqing area. Sedimentary model shows that southeastern Sichuan area was a confined basin in early Silurian Xiaoheba period controlled by the uplift. In the east, controlled by Jiangnan - Xuefeng Mountain uplift, there exist a set of upward coarsening delta deposits. In the south, controlled by the relatively stable Guizhou uplift, carbonate platform deposits are existent on the northern side. The new understanding has an important theoretical and practical significance for more accurately predicting the distribution of the sandstone of Xiaoheba Formation in southeastern Sichuan Province, forecasting favorable accumulation zones and further deploying oil and gas exploration.

Abstract:Abstract：Hetaoyuan Formation in the southern steep slope zone of the Biyang depression is a major hydrocarbon-bearing target zone. Based on the multidisciplinary analysis of drilling core data, petrological characteristics and facies marks, this paper divides the Hetaoyuan Formation into four sedimentary systems: fan-delta deposits, braid river delta deposits, meandering river delta deposits and lacustrine deposits. Based on a comprehensive analysis of detrital heavy minerals, well-logs and well logging data, the authors systematically drew lithofacies-paleogeographical maps from 3rd Member to 1st Member of the Hetaoyuan Formation. The paleogeographic distribution characteristics are as follows: Fan delta is developed in the south, braid river delta occurs in the northeast, meandering river delta exists in the northwest and lacustrine sediments are developed at the center. In the paleogeographical evolution process from 3rd Member to 1st Member of the Hetaoyuan Formation, the fan delta and meandering river delta kept shrinking, and the meandering river delta was filled by the shallow lake in 1st Member of the Hetaoyuan Formation. The area of the lake expanded gradually and the braid river delta became bigger from 3rd Member to 2nd Member and began to decrease in area in 1st Member of the Hetaoyuan Formation.

Abstract:Abstract：The Middle Ordovician Majiagou Formation in Ordos basin was uplifted and eroded because of the Caledonian movement, forming favorable karst reservoirs. Therefore, the study of the sedimentary characteristics is of the key importance in oil-gas exploration. Based on the methods of single factor analysis (including analysis of stratigraphic thickness proportions of dolomite, limestone, gypsum and mudstone) in combination with detailed analysis and statistics of drilling core and logging data, the authors compiled and drew the lithofacies paleogeographic maps of Ma521 submembers. The results show that Ma521 was in a relative regression stage, and developed mainly gypsum-dolomitic flat, dolomitic flat, mud-dolomitic flat and mud-bearing dolomitic flat. According to lithofacies palaeogeographic maps in combination with stratigraphic thickness of Ma 521 , there may be a shallow depression in the middle of the study area, and hence the authors built the sedimentary model of Ma 521 in this area. On such a basis, the lithofacies palaeogeography of Ma521 can be summarized as “flats outside the lands, widespread dolomitic flats, depressions in flats, gypsum in depressions”. According to the lithofacies paleogeography and regional geology of this area, the formation of favorable gas reservoirs has been discussed preliminarily in this paper.

Abstract:Abstract：Guided by the theory of high-resolution sequence stratigraphy, based on the classification of base level cycle sequence, and aimed at the distribution characteristics of sand bodies, this paper has divided Upper Shaximiao Formation into base level cyclic sequences of one long period (L1) and four moderate periods (M1，M2，M3，M4). Sequence-based lithofacies and paleogeographic maps of Upper Shaximiao Formation were compiled on the basis of mapping units of middle period base level cyclic sequence. The result shows that meandering river delta facies and lake facies were developed during the stage of M1 and M2. During the stage of M3 and M4, the depositional setting was changed and characterized by the development of alluvial fan facies, alluvial plain facies, braided river delta facies and lake facies. The sand bodies were distributed in two areas, i.e., Dayi-Wenjiang area and Zhongjiang area: the former occurred during the stage of M1, M3 and M4, whereas the latter came into existance during the stage of M1，M2 and M3.

Abstract:Abstract：The Zhujiangkou basin is a special tectonic location of passive continental margin with complex regional background and oil and gas geological conditions. The region has not only basic characteristics of Cenozoic continental rift and fault basin in eastern China but also its unique features. Because oil and gas geological conditions are different in different basin zones, there exist the regularity of migration and accumulation of oil in the north and that of gas in the south, and the characteristics of association and superimposition of various resources are obvious: The north rift zone and the East Sha uplift shallow water zone constitute the thinning location of the continental crust, with the scale of the fault depression and sedimentation being smaller than that of the deep water area in the north rift zone; in addition, the area has low geothermal gradient and small heat flow, its thermal evolution of source rocks is in the range of oil window, and it produces large quantities of oil accompanied by a small amount of oil type gas, thus forming a petroleum accumulation zone in the sallow water of north continental shelf, which mainly includes Wenchang, Yunping, Xijiang, Huizhou, Lufeng and Liuhua oil fields. The exotic source mechanism of the oil and gas migration and accumulation system is the Oligocene delta sandstone and Miocene reef limestone in the area. There exist large quantities of natural gas and a small amount of light oil, which mainly include gas reservoirs of LW3-1, LH34-2 and LH29-1 and oil reservoir of LH16-2 in eastern Baiyun depression and a small gas reservoir group in Panyu uplift of Baiyun depression, which constitute a rich natural gas district with resource potential of oil and oil-gas in the south rift zone and the south uplift zone. Because the south rift zone and the deep water zone of southern uplift constitute the location of near-ocean crust characterized by thin crust and large-scale fault depression, the area has more marine hydrocarbon source rocks than northern shallow water. There exist high geothermal gradient and large heat flow in this area, and the thermal evolution of the source rocks is at the stage of mature-highly mature condensate oil and wet gas; besides, there is mixed source mechanism of hydrocarbon migration and accumulation characterized by the hydrocarbon system of Oligocene delta coastal sandstone and the deep-water fan system, and there also exists the paragenetic and superimposition relationship between gas hydrates in the seafloor and shallow gas and conventional oil and gas in the deep water.

Abstract:Abstract：According to seismic, well-logging and core data, the micro-facies and type of the third Member of Paleogene Hetaoyuan Formation in Bidian area of Biyang sag were determined on the basis of sedimentary structures, lithological textures of profiles and thicknesses of sandstone bodies. Using the new methods for seismic inversion, the authors obtained the thickness of the iso-chronological single sandstone body and drew the distribution map of sedimentary micro-facies by tracing thin sandstone reservoirs from three-dimensional data. It is shown that there exist widely-distributed deposits of turbidite fans and sliding turbidite fans characterized by the turbidity-flows sediments, and sedimentary frameworks of north and south turbidite fans interbedded with the deep-water lacustrine sediments at the center. Sedimentary evolution, rich early turbidite sandstones and late deep-water mudstones suggest relative rise of the lacustrine level. In the light of favorable facies zones, the authors predicted and evaluated subtle traps of the sag, thus providing a basis for petroleum exploration.

Abstract:Abstract：Luzhou uplift in Sichuan basin is an important area for oil and gas exploration,and Jialingjiang Formation is the main producing formation in this area. Under the guidance of theories and methods of carbonate reservoir geology and on the basis of core observation, cast thin section analysis, SEM and analytical data of physical property and pore structure, in combination with new information and new achievements obtained recently, the authors studied in detail the petrologic characteristics of Jialingjiang Formation, the storage space type, pore features and electrical performance characteristics of Jia II1-Jia I and Jia II3 reservoirs in Danfeng-Tanghe area. Researches show that Jia II1-Jia I and Jia II3 reservoirs in the study area are mainly powder fine-crystalline and grained dolomite,and the accumulation spaces are mainly secondary pores（intergranular dissolved pores and dolomite intercrystalline pores）. The reservoirs are mainly of the pore type and the fracture-pore type. Researches show that ① the beach of platform facies controlled the distribution scale and range of the reservoir；② dolomitization constituted the basis of reservoir composition；③ karstification and tectonic action played a most important role in expanding the reservoir distribution and improving the physical character of the reservoir.

Abstract:Abstract：The diagenetic manner and evolution stage as well as the corresponding geological products and geochemical characteristics of REE, carbon, oxygen and strontium stable isotopes of Xekar Middle Ordovician Organic Reef-beach facies reservoirs were comprehensively studied in this paper. According to the “hydrological system”, the Middle Ordovician organic reef-beach facies strata were divided into four diagenetic systems, i.e., pore water, atmosphere water, temperature-pressure water and oilfield brines. The source and property of fluid flow and the interaction process between fluid and rock of each diagenetic system were different from each other, and their effects on the reservoir development were varied. Therefore, the diagenetic systems and manners closely related to the reservoir development mainly include the role of the karstification of atmospheric water at the ancient epigenetic stage, the role of temperature-pressure water and oilfield brines at the re-burial diagenetic stage, and the role of tectonic disruption at the middle-late re-burial diagenetic stage.

Abstract:Abstract：Volcanic reservoir is usually of dual porosity medium character. The reservior spaces can be classified into two genetic categories： primary reservior spaces (PRS) and secondary reservior spaces (SRS), and most of the latter were generated from the fomer by late diagenesis. Based on extensive identification and description of casting thin section, this paper divided the PRS of Carboniferous igneous rocks in Dixi area into five types of primary pores (gas pores, residual amygdale, intergranular pores, intragranular pores and intercrystal pores) and four types of primary fractures (shrinkage joint, explosive fracture, intergravel crack and intercrystal crack). In combination with the influencing factors such as environment and intensity of eruption and texture and structure of rocks and according to the evolution features of magma at different stages, the formation of PRS is divided into four stages： "magma chamber" stage, outpouring surface stage, diagenetic stage of condensation and deuteric hydrothermal stage, of which the outpouring surface stage and diagenetic stage of condensation were the main periods to form primary apertures while the hydrothermal stage was the period when the number of apertures was reduced. The speed of crystallization constituted the key factor for the formation of different types of PRS. The study of the formation mechanism of igneous PRS can reveal the distribution of SRS and is of great significance in the prognosis of favorable reservoir zones.

Abstract:Abstract：Lots of evidence shows that magma mingling existed in the Jiama ore deposit. It is of great geological significance to study the magma mingling. Based on tectonic and magmaic theory, this paper has established tectonic and magmaic evolutionary sequence of the Jiama ore deposit in the Gandise metallogenic belt according to structural association features and genesis of the granitoids. It is held that underplating was the direct power in the process of magma mingling, the original mechanism of mixed magma might have been the pre-mingling and emplacement that occurred at 15 Ma 40% basic end-member (mafic magma) and 60% acid end-member (granodioritic gneiss) , and the re-mingling of magma happened again along with mechanical mixture. The metal elements and S in ore-forming fluid came from mantle-derived mafic magma, inmplying that the mingling of magma contributed to mineralization.

Abstract:Abstract：The Shihlu ore deposit in Hainan is one of the famous mining areas not only for large amounts of iron but also for considerable economic values of associated minerals such as copper and cobalt. This paper reevaluated the major factors controlling the orientations of ore bodies, and discussed the source of metallogenic materials, the relationship between magmatic activity and the metallogenic process, and the metallogenic epoch. The results show that the metallogenic materials of the Shilu ore deposit were possibly derived from the Shilu Group of primary volcanic-sedimentary formations, and later regional metamorphism and magmatic activity played an important role in the transformation and concentration of these material. On such a basis, the authors defined initially it as the type of the volcano-sedimentary metamorphic and multi-period hydrothermal superimposition transformation. This paper summarized the metallogenic model of the Shilu ore deposit as follows: 1) Submarine volcanic exhalation stage in Neoproterozoic period, which established the foundation of metallogenic materials of Fe-Co-Cu; 2) Metamorphic metallogenic stage in Caledonian-Hercynian period, which formed the lean metamorphic ore bodies; 3) Hydrothermal transformation stage of Indosinian-early Yanshanian period, which caused important transformation and concentration of the ore deposit, and produced rich iron ore bodies; 4) Hydrothermal transformation stage of late Yanshanian period, which transformed the original ore bodies, and produced the vein/breccia iron ore bodies and also the associated copper-cobalt ore bodies.

Abstract:Abstract：The Denggezhuang gold deposit is one of the most typical quartz vein gold deposits in the Muping-Rushan metallogenic belt in Jiaodong peninsula, and hence it has great academic significance and economic value. Ore bodies are located in the Kunyushan rock mass close to the contact zone between Jingshan Group metamorphic rocks and Kunyushan rock mass. Wall rock alterations of the ore deposit are relatively well developed, characterized by multiple stages and significant zonal structure. Ore bodies are controlled by the NNE-trending sub-fractures west of Jinniushan fracture zone. Based on a study of the “three in one” ore-forming model, the authors hold that the formation age of the vein rock is the same as the ore-forming age, and this vein rock and early Cretaceous magmatic rock are respectively Ⅰand Ⅱ grade ore-forming geological bodies. Jingshan Group metamorphic rock served as the activator, Jiaodong Group partially provided ore materials, magmatism provided heat source for multiple ore-forming fluids, and fractures played the role of dynamics and location space. The precipitation of ore-forming materials usually occurred in the locations of abrupt change of the attitudes of fractures and the branching and compounding of different faults. Combined with the results of vertical zoning of gold grades and thickness mapping, this paper summarizes prospecting criteria, discusses the concentration rules of gold mineralization, and suggests that at the depth of -400～1000m in the northeast direction of No. 94 exploration line of No.Ⅰ2-2 ore body there may exist favorable prospecting potential.

Abstract:Abstract：The Jinqingding gold deposit with identified reserves of more than 50t is currently the largest lode gold deposit in terms of single vein gold resources and is also a superlarge gold deposit located in the middle part of the Muping-Rushan gold belt in Jiaodong; nevertheless, the genetic type and source of ore-forming fluids in the gold deposit constitute a problem that needs urgent solution. A study of trace elements and REE compositions and features of gold-bearing pyrite from No. Ⅱ ore body of the Jinqingding gold deposit reveals that the pyrite displays hydrothermal characteristics with Co/Ni ratios from 2.317 to 11.734 (7.17 on average). The HFSE indicates that the ore-forming fluid originally belonged to the F-rich system and generally evolved into the Cl-rich system at the chief metallogenic stage, and the distribution patterns of REE shows that the source of matallogenic materials was not mainly from Mesozoic Kunyunshan monzonitic granite. According to an analysis of the characteristic parameters (3He/4He=0.1~2.2 Ra（0.60 Ra on average）)，40Ar/36Ar =462.7~1507.5（831 on average），it is considered that the source of matallogenic materials was mainly derived from the lower crust and was contaminated by meteoric water during the intrusion，and the mantle fluids were involved in the metallogenic process.

Abstract:Abstract：The decrepitation method of fluid inclusions was used in former Soviet Union and China in the 1970’s and 1980’s to help mineral exploration. This method can be used in combination with other measurements in mineral exploration. Previous studies of the decrepitation method have shown that the decrepitation intensity (frequency) near the ore body is high and will decrease gradually with the increasing distance from the ore body, which is believed to be caused by strong hydrothermal activity and relatively high abundance of fluid inclusions around the ore body. Hence, positive anomalies are likely to occur in/around the ore body. Samples were collected from 8 drill holes along No. 112 and 144 exploratory lines in the Jiaojia gold deposit in northwestern Shandong Peninsula, and quartz separates from the samples were analyzed by DT-4 acoustic decrepitometer developed by Prof. Xie Yihan of the Institute of Geology and Geophysics, Chinese Academy of Sciences in Beijing. The results show that the unaltered granites in the Jiaojia gold deposit exhibit high decrepitation frequencies and their decrepigrams (decrepitation curves) have a pronounced peak with normal distribution in the temperature interval of ca.360~450℃ and a sharp peak at 573℃ which is the phase transition temperature of α/β-quartz. With the increase in alteration intensity, the decrepitation frequencies decrease from the K-feldspathization zone through the pyrite-phyllic alteration zone to the gold ore. The decrepigrams of gold ores in the mineralization center become weak-waved curves or nearly horizontal lines with very low decrepitation frequencies, and negative steam aureoles occur around the gold ore body. Hence the unique decrepigrams and negative steam anomalies can be applied to gold exploration in northwestern Shandong peninsula.

Abstract:Abstract：With increasing large-scale exploration of coal resources, coal reserves have been reduced year by year, and outcrop and shallow ore deposits are diminishing day by day, particularly in eastern China. Therefore, the main exploration targets should be focused on concealed or blind coal deposits whose detection and exploration are rather difficult, and modern remote sensing and geographic information system technology can play an important role in this aspect. Based on coal-prospecting practice in the past, this paper describes the methods and problems of remote sensing for coal exploration, and puts forward some new ideas: analyzing a variety of geographical attributes, surface properties, geophysical and geochemical exploration, geological drilling results and remote sensing image data and using new remote sensing data with multi-band, multi-polarization, multi-angle, multi-temporal and multi-resolution characteristics to investigate geological setting and mineralization regularity and extract coal information in depth.

Abstract:Abstract： Based on a summary and analysis of the analytical data of the formation water in 451 wells, the authors studied the characteristics of the salinity and types of the formation water of Maokou Formation in Shunan area. In combination with the drilling, seismic and logging data, this paper has systematically summarized the vertical zonal mode of the paleokarst, elaborated the development features of various karst zones along the profile, and analyzed the storage styles of the formation waters with different chemical properties. The result shows that the salinity of the formation water is on the whole relatively low with a large variation range and that the distribution of the salinity is connected with the potential energy. CaCl2-type formation water is of high salinity, positive condensation, high metamorphism and slow seepage. NaHCO3-type water, Na2SO4-type water and MgCl2-type water have low salinity, their existence is related to karstification, and the place of their distribution is of negative water property. The paleokarst system can be divided into four vertical sections： surface karst zone, vertical infiltration karst zone, horizontal runoff karst zone and deep underflow karst zone, with each zone having its own features. The generation of CaCl2-type formation water is related to such factors as the leaching of atmospheric water, the releasing of compaction water, and the burial metamorphism. Such formation water is stored in pores in the form of deep resident water while the low-salinity water is kept in the karst closed system in the form of burial water.

Abstract:Abstract：Land subsidence induced by excessive groundwater withdrawal has constituted a major environmental geological problem in Beijing plain area. The construction of the monitoring network of land subsidence in Beijing began in 2002 and the network had covered the whole plain area by the end of 2008. Based on the data from layered marks and groundwater observation wells, the authors drew curves of variations over time in the aspects of both soil mass deformation and water level and relationship between soil mass deformation and water level, and carried out an analysis of deformation behaviors of soil mass with various lithologic characters at different depths depending on the corresponding water levels. As a result, the deformation behavior of soil mass is generalized into five categories. Some conclusions have been drawn： (i) the deformation rate of the shallow soil mass in the present is slowing down, and most of the mid-deep and deep soil masses are still in continuous compression at a faster speed; (ii) the sand strata are characterized by elastic deformation,and clay soil mass at different depths is usually characterized by elastic-plastic deformation and creep deformation and can be considered to be visco-elastoplastic materials.

Abstract:Abstract：The assessment of geohazard danger constitutes an important basis for the work of disaster prevention and mitigation. In this paper, the author collected the remote sensing images of IKONOS, topographic maps and field survey data, and extracted the evaluation factors of rock fall and landslide based on remote sensing information extraction technology and GIS Spatial Analysis. Then the factor scores were determined by information method and calculated susceptibility of rock fall and landslide. At last, the new danger calculation method of rock fall and landslide was put forward, and the rock fall hazard zonation map and landslide hazard zonation map were drawn. The results show that the new rock fall and landslide risk assessment method can reflect the risk degree of geological disasters in the study area. The method is feasible and the results are reasonable. This achievement has provided a useful idea for large-scale regional geological hazard study.

Abstract:Abstract：The Regional Geological Mapping System, well operated in terms of its function and utilization, was briefly discussed in this paper. The authors found in its application that this system has some shortcomings. first, in the process of measuring the regional geological section, the increasing inaccuracy due to the increasing length of the section will finally lead to the remarkable deviation of the end of the section from its actual one because of the inaccuracy in measuring the azimuth angle, grading angle and slope length. Second, before the measurement of the section in a radioactive ore district, we need to measure the γ-ray spectrometry, but the resultant data can’t be involved in the Regional Geological Mapping System. Third, the stratigraphic thickness of the special section will not be included in the calculation of the thickness of the strata in the Regional Geological Mapping System (RGSETION). For example, it’s probable that some lines go backward while most of them continue going in their original direction. If this really happens, the thickness of the strata of these lines that go backward will be calculated again. Fourth, the attitude measured by the digital geological compass should be transformed in the tablet, but the use of the digital geological compass will be greatly limited because it can’t directly display the attitude measured by it itself. For solving these problems, the authors put forward some suggestions in this paper. In combination with the experience obtained in the field and indoor work concering the utilization of the Regional Geological Mapping System, the authors also illustrate some practical skills in this paper.

Abstract:Abstract： Radiolaria fossils were discovered for the first time in the lower Cambrian and middle Ordovician strata of the South China orogenic belt. They occur in argillaceous slate of the lower Cambrian Niujiaohe Formation in Pingxiang of Jiangxi Province and silicalite of the middle Ordovician Yanxi Formation in Yongzhou of Hunan Province. The discovery of Radiolaria shows that there might have existed a low-latitude sea basin of considerable scale in Pingxiang-Yongzhou area in Cambrian-Ordovician period.