Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
This paper is the study on the ore-forming laws and prospecting predictions of chromite deposits in the Hegenshan area, Inner Mongolia. [Objective] Summarize the geological, geophysical, and geochemical characteristics of chromite deposits in the Hegenshan area of Inner Mongolia, summarize the regional ore-forming elements and prospecting indicators, and conduct research on prospecting prediction. [Methods] In the Hegenshan area of Inner Mongolia, regional gravity, magnetic methods, and physical property measurements were carried out. [Results] The results of regional gravity and aeromagnetic surveys show good consistency between high-value anomalies and ultrabasic rocks and major faults, thus identifying 34 areas with local gravity anomalies and inferring 5 faults. [Conclusions] Based on the comprehensive analysis of regional geology, geophysics, geochemistry, and other ore-forming elements and prospecting indicators, summarize the ore-forming laws and delineate 9 prospecting areas.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
This paper is the research of uranium deposits prospecting direction.
[Objective] The intermittent period of the Huanghu Ridge volcanic activity in Ganhuai belt, Jiangxi Province, China, produced a set of uranium-rich volcanic lava that is disposed in a layered manner within the Maqian Basin. The volcanic lava directly controls the spatial distribution of uranium ore bodies. Therefore, the study of the characteristics of uranium-rich volcanic lava is of great significance for analyzing the volcanic activity of this period, judging the source of mineralization, and indicating the direction of uranium exploration in the basin. [Methods] Based on the petrographic characteristics of the third section of the Yuhu Volcanic Group in the Zhujia Mine area of the Maqian Basin, this paper analyzes and tests the chemical element contents of the uranium-rich volcanic lava, the altered rocks, and the uranium ore stones. [Results] By summarizing the changes of chemical elements in the rocks and comparing and analyzing the characteristics of Andesite in adjacent areas, it is concluded that uranium-rich volcanic lava is Andesitic breccia lava and Andesite, which is rich in alkali, iron and titanium, and rich in light rare earth elements and large ionic lithophile elements (Rb, Ba, K). With the increase of uranium content in the rocks, the content of heavy rare earth elements in the ore of the Andesite series of potassium basalt lavas characterized by the loss of high field strength elements (Nb, Ta, Ti) continues to increase. It is concluded that the uranium-rich volcanic lava is formed by the volcanic eruption caused by the coupling of volcanic magma and deep uranium-bearing hydrothermal at the same period, and there is continuous uranium-bearing hydrothermal transformation in the later period. [Conclusions] Based on the characteristics of uranium-rich volcanic rocks, the search for concealed uranium-rich volcanic rocks of the Ehu Lake Late-Middle Period in the basin should be the focus of the next phase of uranium exploration work using geophysical prospecting methods, mainly magnetic survey.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
This paper is the result of research on the lithospheric mantle.
[Objective] In terms of petrological and geochemical studies on a large number of mantle xenoliths, melt-peridotite reactions always occur in subcontinental lithospheric mantles, especially in the North China Craton (NCC). Based on the mineral metasomatic characteristics of mantle xenoliths and the related element geochemical signatures, the reaction between silicate melt and peridotite is the main type of melt-rock reaction within the NCC lithosphere mantle. However, the direct evidence of experimental petrography about the mechanism is insufficient. [Methods] In this contribution, natural olivine of harzburgite from Hebi, Henan province, and tonalite from Sandouping, Huangling, Hubei province were collected as starting material. The Si-rich melt-olivine reaction experiments were performed at conditions of 1 200～1 400 °C, 1.0～1.5 GPa, on LC25-0300/50 piston-cylinder apparatus equipped at Key Laboratory of High-temperature and High-pressure Study of the Earth’s Interior, Institute of Geochemistry, Chinese Academy of Sciences, which explored the reaction mechanism and kinetics of the melt-peridotite reaction. [Results] The main crystallized phase under experimental conditions is orthopyroxene, its En content ranges from 73 to 100 discriminated into enstatite. After reactions, the MgO content of reacted melts increased and linearly correlated with the temperature, while the contents of SiO2, Al2O3 and K2O decreased linearly with the increase in temperature. As the temperature increased, more forsterite was dissolved in the melts, and with more orthopyroxene generated, the SiO2, Al2O3 and K2O of melts decreased which changed the composition of the melts. Under the pressure of 1.0GPa, the temperature rises from 1 250°C to 1 350°C, the SiO2, Al2O3, and K2O in the residual melt decrease from 66.20%, 17.24% and 1.40% to 61.91%, 16.02%, and 1.28% respectively, however MgO in the residual melt increases from 3.93% to 8.26%. Under the pressure of 1.5 GPa, the temperature rises from 1 250°C to 1 400°C, the SiO2, Al2O3 and K2O in the residual melt decrease from 65.79%, 17.64% and 1.36% to 61.74%, 15.78%, and 1.23% respectively, however MgO in the residual melt increases from 3.11% to 7.07%. [Conclusions] The pressure has a much less influence on the chemical composition change or residual melts than the temperature. In all reactions between Si-rich melt and olivine, orthopyroxene was newly formed the experimental results also explain the composition of the peridotite in NCC and the phenomenon of the orthopyroxene veins in the peridotite, which can transform the lithosphere mantle from refractory into fertile.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
This paper is the result of geochemical research.
[Objective]The volcanic rocks of the Tiaojishan Formation in Western Liaoning not only represent the beginning of the Yanshanian large-scale volcanic eruption, but also are closely related to the time, scope and mechanism of the Craton weakening in North China.In recent years, a lot of new understanding has been obtained on the petrogenesis of the Tiaojishan Formation volcanic rocks, but itstectonic background, magmatic source area are still controversial. [Methods]Zircon U-Pb dating, Hf isotope composition and geochemical characteristics were analyzed in the core samples from the continuous drilling of borehole Yang D1. [Results]The results of zircon U-Pb dating show that the zircon U-Pb age of trachyte in the lower part of Tiaojishan Formation is 162.8±1.7 Ma, and the U-Pb age of tuff at the bottom of Tuchengzi Formation is 153.8 ±1.7 Ma. We believe that the volcanic rocks of Tiaojishan Formation formed in the Late Jurassic. In addition, the trachyte of Tiaojishan Formation is characterized by light rare earth enrichment, heavy rare earth deficit, and low Sr and Yb-type magmatic rocks, which indicates that the trachyte of Tiaojishan Formation is produced by partial melting of crustal magma under high pressure and accompanied by insignificant crystallization differentiation. The εHf (t) values of the zircons range from -22.1 to -15.4, and the two-stage model ages (TDMC) range from 2.182～2.604 Ga, indicating that the Tiaojishan Formation is mainly derived from the late Archean magma source, which indicates that the Tiaojishan formation was formed by the partial melting of the basic rocks in the lower crust under the background of the Pacific plate subduction to Eurasia continent. [Conclusions]The research results define the formation age and magma source area of the Tiaojishan Formation volcanic rocks, and provide a scientific basis for exploring the Mesozoic magmatic and regional tectonic evolution of the Yanshan orogenic belt.
Highlights:This article selects reliable continuous drilling core samples for the first time and applies zircon U-Pb geochronology and Lu Hf isotope analysis methods to provide new evidence for clarifying the age attribution and magma source area of the Tiaojishan Formation.The research results obtained provide a scientific basis for exploring the Mesozoic magmatic evolution and regional tectonic evolution of the Yanshan orogenic belt.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
This paper is the result of ecological environment.
[Objective] Ecological environment is the foundation for the survival and development of human beings. Remote sensing technology is used to evaluate and analyze the quality and status of the ecological environment in Chengde City provides scientific basis and technical support for the protection and governance of the ecological environment in Chengde City. [Methods] This study is based on Landsat series remote sensing images, and uses ENVI software to calculate four indicators reflecting the ecological environment: greenness, wetness, dryness, and heat. In addition, the principal component analysis method is used to construct a remote sensing ecological index model to evaluate the ecological environment quality of Chengde City. [Results] The remote sensing ecological index model was constructed by using four indicators calculated from remote sensing images of Chengde City in 2013, 2016, 2019, and 2022, and further analyzed, showing that: (1) The first principal component index in the principal component analysis was used to construct the RSEI model. NDVI (representing greenness) and WET (representing wetness) had a positive effect on the ecological environment quality, while NDBSI (representing dryness) and LST (representing heat) had a negative effect on the ecological environment quality. (2) From 2013 to 2022, the average RSEI value of Chengde City increased from 0.625 to 0.640, and the ecological environment quality showed an overall upward trend, and the ecological environment was basically improved. (3) From 2013 to 2022, the area of ecological environment deterioration in Chengde city is 2 405.562 3 km2 , accounting for about 6.07% of the total area; The unchanged area is 28 769.067 km2 , accounting for 75.54% of the total area. The improved area is 8 483.1885 km2 , accounting for 21.39% of the total area. [Conclusions] From 2013 to 2022, the overall ecological environment quality of Chengde City has shown a significant initial improvement trend. This study can provide a reference basis for regional environmental protection work in Chengde City.
Highlights: Based on remote sensing technology, RSEI was used to conduct a time series analysis of the ecological environment quality in Chengde City from 2013 to 2022. By comparing the RSEI values of different years, the dynamic changes in the ecological environment were revealed. Combined with rainfall and temperature factors, the reasons for the changes in the evaluation results were analyzed, and regional environmental protection measures were proposed. This helps Chengde City understand the long-term changes in the ecological environment and provides a scientific basis for formulating long-term ecological protection policies.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
This paper is the result of debris flow hazard study.
[Objective]The debris flow, because of its wide range, rapid disaster and great harm, has caused damage to the basic engineering fa‐cilities in the mountain area, and seriously hindered the regional economic development. In recent years, geological disasters have occurred frequently in the mountainous areas of Beijing. Yanqing District, as the ecological conservation area of Beijing, has many tourist attractions, but there are also many hidden dangers of debris flow. [Methods]In order to reduce the potential threat of debris flow, it is very important to study related debris flow in Yanqing District. In this paper, the debris flow ditch in Chashikou village of Yanqing District is taken as the research object to analyze and forecast the risk. [Results]The results show that loose deposits of Maoshangou can be categorized into three types: alluvial and diluvial deposits, residual-slope deposits, and artificial deposits, with a dynamic reserve of 9.9 × 104 m3 . From the peak flow value and the total amounts of solids washed out by the primary debris flow, it can be determined that the size of this debris flow is medium. By varying rainstorm frequencies (10-, 20-, 50-, 100-year rainfall events), the respective hazardous areas are measured to be 0.004 4, 0.005 1, 0.005 9, and 0.006 8 km2 . The stage of debris flow devel‐opment is considered to be a recession period. [Conclusions]After thorough discussions, it was found that the chances of the debris flow gully erupting into a medium-sized debris flow are high, which will pose a hazard to the residents of the downstream roads and villages. The detailed study of this ditch not only helps to deeply understand the mechanism, dynamic characteristics and develop‐ment trend of the debris flow in this region, but also provides a reference for the study of debris flow and disaster prevention and control of the single ditch under similar geological conditions.
Highlights: At present, there is relatively little research on single-channel debris flow in Beijing area, especially in Yanqing area. In this paper, the breeding conditions and basic characteristics of Maoshan Ditch in Yanqing area are studied. In terms of predicting the scope of potential danger areas, this study introduced the influence of terrain change and flood peak discharge on debris flow, so as to make the prediction results more accurate and provide a reference for subsequent scientific research and disaster prevention and mitigation practice.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
This paper is the results of geothermal energy.
[Objective]Zhecheng, Shangqiu, is located in a sedimentary basin,the Cenozoic deposits are thic, the thermal reservoir cap rock is good, the thickness of thermal sand layer is relatively large, so it has a good prospect of thermal storage. [Methods] Based on temperature data from 33 boreholes around Zhecheng, and more than 80 borehole geological data and regional 2-d seismic exploration results, the geological structure and geothermal field in this area are analyzed. [Results] This study clarified the cenozoic thickness and geological structure distribution in the study area, and analyzed the development history of geological structure. Through the analysis of borehole temperature measurement data, the geotemperature gradient and distribution law of geotemperature in this region are determined.The main factors controlling temperature distribution in the study area are analyzed. The distribution law of geotemperature gradient in Cenozoic and bedrock，thermal reservoir location and favorable geothermal target area are obtained, [Conclusions] the study shows that the difference of the earth temperature distribution is mainly controlled by the basement structure.The origin of the Cenozoic heat storage is mainly conduction type, and the conduction-convection-conduction plays a major role in the vicinity of bedrock and fault zone.
Highlights: Statistically summarized the geothermal gradient and distribution pattern in the region, and analyzed the geothermal genesis mechanism in the area.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
This paper is the results of geothermal resources exploration, utilization and management.
[Objective] Tianjin's geothermal resource endowment has outstanding advantages, and it is in a leading position in geothermal exploration, development, protection and management in China. However, under the background of the construction of ecological civilization, the security of energy resources and the realization of the goal of " double carbon, " the utilization and management of geothermal resources are still deficiency, which needs further research and discussion. [Methods] Based on the history and achievements of the utilization of geothermal resources in Tianjin, this paper discusses the current situation and existing problems of the utilization of geothermal resources, clarifies the challenges faced by geothermal management, and puts forward specific countermeasures and methods to scientifically guide the sustainable utilization. [Results] In the future, the control degree of geothermal exploration in Tianjin should be improved, and the geothermal resources of 4 000~6 000 m should be found out to ensure the supply of resources; Key technologies such as prevention and control of sandstone pore-type reinjection attenuation, reservoir reconstruction and injection of exogenous water should be strengthened to improve resource carrying capacity; It is necessary to promote multi-energy combination, grid-connected interconnection, reduce tail water temperature, improve heat supply efficiency and increase heat supply capacity; Strengthen the unity, integrity and guidance of geothermal resource management, and create a policy environment conducive to the development and utilization of geothermal resources. [Conclusions] Tianjin has a long history of geothermal exploration, and the method is perfect. Geothermal development and protection are equally important, and the management system is increasingly standardized, which has played a leading role in the national geothermal exploration. In the future, we should improve the degree of exploration and tap the deep geothermal resources; Break through the technical difficulties of sandstone reservoir reinjection attenuation, reasonably set the layout and development mode of geothermal resources utilization. Improve the life cycle management mechanism of geothermal wells, innovate the management mode of geothermal resources, and promote the healthy and orderly development of geothermal industry.
Highlights: The history and achievements of the exploration , utilization of geothermal resources in Tianjin are discussed; The promotion effect of standardized management on the geothermal industry is studied for the first time; and the shortcomings and challenges at the present stage are clarified. The measures for sustainable development and utilization of geothermal resources are put forward from multiple perspectives, which provide a guarantee for the healthy and orderly development of geothermal industry in Tianjin.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
This paper is the result of ground matrix survey.
[Objective] At present, the investigation of black land surface matrix is widely carried out in Northeast China, and various geophysical methods are important means to investigate the vertical structure characteristics of black soil surface matrix. In this paper, the typical surface matrix area in the Molidawa Daur Autonomous Banner ( Moqi for short ) of the Songnen Plain was selected to carry out micro-tremor exploration profile measurement and array measurement，so as to verify , the application effect of micro-tremor exploration method in the vertical structure investigation of black land surface matrix.[Methods] In this paper, the microtremor exploration technology combining artificial source and natural source surface wave is used. By extracting the surface wave dispersion curve of each measuring point for inversion analysis, the wave velocity and vertical spatial structure characteristics of different matrices are inferred by using the apparent shear wave velocity change, and the vertical structure characteristics of the surface matrix layer ( 0 ~ 40 m ) are obtained in combination with drilling verification.[Results] Based on the investigation of the micro-motion profile in the typical area of Moqi Banner, combined with borehole correction and regional physical parameters, the two-dimensional apparent shear wave velocity profile and three-dimensional array model of the study area were drawn. The spatial structure, soil type, soil matrix thickness and distribution characteristics of the surface matrix layer of 0 ~ 40m in these areas were explored, and the geological characteristics and apparent shear wave velocity range of the surface matrix layer in the study area were obtained. [Conclusions] Through this study, it is found that the combined exploration effect of artificial source and natural source surface wave is remarkable. Effectively combining the advantages of both can improve the exploration depth and shallow resolution, enhance the exploration ability of a single method, and is an effective geophysical method suitable for surface matrix layer investigation. It can provide scientific and effective data support for the vertical structure survey of surface matrix survey.
Highlights: ( 1 ) In this paper, a dual-source microtremor exploration method combining artificial source and natural source is used to improve the frequency band range of surface wave dispersion curve by mutual verification, thus improving the accuracy of shallow shear wave velocity structure. ( 2 ) Based on this method, the surface matrix investigation in the typical area of Moqi was completed, the spatial structure and soil type of the matrix layer were clarified, and the two-dimensional profile and three-dimensional model were constructed, which can provid scientific data support for surface matrix investigation and black land resource protection.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
[Objective] East Tibet is located in the southwest Sanjiangmetallogenic belt with good metallogenic conditions. In this paper, based on the aeromagnetic survey results of the geotransport project, the aeromagnetic anomalies with good abnormal shape (Zang 16-35) were selected for comprehensive investigation of the geophysical and geochemical surface, and the causes of the anomalies were identified. [Methods]The geological profile survey, high precision ground magnetic survey, soil geochemical profile survey were carried out, and the cause of the anomaly was analyzed by means of profile inversion. [Results]The results show that there is an obvious malachite mineralization alteration zone on the surface, located in quartz diorite, and the shape of the ground magnetic anomaly is regular, the element content is higher than the background value, and the location of the geophysical and geochemical anomaly corresponds well. [Conclusions]It can be inferred that the survey area where the anomaly is located has a good prospecting prospect, and it also has reference significance for the verification and prospecting of other anomalies in this area.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
[Objective] The Inductively coupled plasma source (ICP) in the multi-collector Inductively coupled Plasma Mass Spectrometer (MC-ICP-MS) is a kind of high temperature ionization source under atmospheric pressure, which is produced by the interaction of several sophisticated components and is an important component of MC-ICP-MS, The Plasma Generation Process of the Mass Spectrometer is mainly performed by the ICP. It is necessary to strengthen its routine maintenance and failure analysis. [Methods] Taking the MC-ICP-MS(NEPTUNE) of Thermo Fisher Scientific as an example, This type of mass spectrometer mainly has plasma source fault, electronic fault, vacuum fault, gas support fault, circulating water support fault, etc. among which plasma source ignition fault is particularly common, and the influencing factors are complex. [Results] On the basis of a detailed introduction to the working principle of ICP and the maintenance experience of each of its components, the fault phenomena and treatment methods in the ignition process of this instrument are summarized in detail. [Conclusions]Pay attention to the routine maintenance and failure analysis of the plasma source can greatly improve the utilization of Neptune and ensure the acquisition of high-quality measurement data. It provide reference for the use and maintenance of the instrument.
Abstract (
)
Download PDF (
)
Rich HTML
Knowledge map
Save
This paper is the result of titration of total nitrogen content in rocks. [Objective] This article established an analytical method for determining total nitrogen content in rocks using a fully automatic Kjeldahl nitrogen analyzer by conducting research on optimizing digestion procedures, distillation time and other experimental conditions, as well as accuracy of methods. [Methods] This method added sulfuric acid during the digestion process, and the nitrogen-containing organic matter in the sample was transformed into inorganic ammonium nitrosulfate. Under the action of a catalytic plate that made of potassium sulfate and pentahydrate copper sulfate, the reaction was accelerated, and ammonia gas was released by reacting with sodium hydroxide which was collected in a boric acid solution and titrated with standard hydrochloric acid solution for total nitrogen. [Results] The results showed that the detection limit of the method was 23.90 μg/g and the method was validated using the national first-class standard material GBW 07729, with a relative standard deviation (RSD) of 1.07% (n=4), and the recovery rate of the experiment was between 95.40% and 103.8%. [Conclusions] This method used a fully automatic Kjeldahl nitrogen analyzer to determine the total nitrogen content in rocks which is simple and accurate, and could fully meet the testing requirements of the geological industry.
Highlights: 1. By optimizing the experimental conditions, a method for determining the total nitrogen content in rocks has been es‐tablished. 2. The use of fully automatic Kjeldahl nitrogen analyzer elimenated the errors caused by human factors in determining thetitration endpoint, and improvd the testing accuracy
Office
