This paper is the result of rock geochemistry.
[Objective]The Baoerhantu Group is mainly distributed in the northern region of Damao Banner and is a key area for studying the early Paleozoic tectonic evolution of the ancient Asian Ocean. [Methods]This article conducts petrological, geochemical, isotopic geochemical and chronological studies on the basic volcanic rocks in the Baoerhan map of Damaoqi area, in order to explore their formation age and diagenesis. [Results]The LA-ICP-MS zircon U-Pb diagenetic age of the gneiss like plagioclase amphibolite in the Baoerhantu group was 495 ± 2.0 Ma, while metamorphic zircon ages of 242.3 ± 1.1 Ma and 249 ± 3 Ma were obtained in the amphibolite greenstone and plagioclase amphibolite, respectively. [Conclusions]The geochemical characteristics of the gneiss like plagioclase amphibolite are characterized by enrichment of large ion lithophilic elements such as Rb and Th, and depletion of high field strength elements such as Nb, Ta, P, and Ti, indicating that the Baoerhantu Group had volcanic eruptions during the Cambrian (ε3), and its formation is related to the subduction of the ancient Asian Ocean from north to south. The hornblende epidote and plagioclase hornblende exhibit MORB type geochemical characteristics, and the captured zircons contain both the ancient recycled continental crust material of the North China Plate and the newly formed basic lower crust material of the Paleozoic era, which can
limit the closure of the ancient Asian Ocean to be earlier than 249 Ma.
This paper is the result of the research on the geochronology, geochemistry and tectonic setting of volcanic rocks.[Objective] The volcanic rocks of Baiyingaolao Formation in the southern section of Da Hinggan Mountains are the host rocks of the Changtuxili Ag-Pb-Zn-Mn polymetallic deposit. Conducting research on volcanic rock chronology, geochemistry, and tectonic environment is of great significance for identifying the geological background of the deposit and guiding the next exploration of the deposit. [Methods] This study conducted petrological, zircon U-Pb geochronological, and geochemical studies on the volcanic rocks of the Baiyingaolao Formation to clarify their formation age, petrogenesis, and tectonic evolution environment. [Results] The main body of the Baiyingaolao Formation in this area is a set of rhyolite and rhyolite volcanic clastic rocks. The zircon U-Pb dating result is (133.85±0.81 Ma), which was formed in the Early Cretaceous. The main elements have the characteristics of high silicon(SiO2=71.00%~74.43%), rich alkali (ALK=7.10~8.78), rich potassium, high FeOT / MgO ratio(7.51~22.54), poor magnesium(MgO=0.11%~0.45%), and poor calcium(Ca=0.88%~1.83%), belonging to the high potassium calcium alkaline series rocks. All samples have a similar REE pattern with medium total REE contents (ΣREE=156.66~211.81), significant fractionation of LREE and HREE ((La / Yb)N=9.39~16.91), attributed to the enrichment type with strong negative Eu anomalies (δEu=0.38~0.59). Similar REE distribution patterns imply that the volcanic rocks came from the same magma source. The trace element geochemistry shows evident enrichment of LILE Rb, K, Th and U, deficit of HFSE Nb, Ta, Ti, P.[Conclusions] Based on regional geological data and the research results of this article, it is believed that the volcanic magma of the Baiyingaolao Formation in the study area originated from partial melting of crustal rocks and was generated in the post orogenic extensional tectonic background. Its formation is mainly related to the lithospheric extension after the closure of the Mongol-Okhotsk Ocean, and the subduction of the ancient Pacific Plate also has a certain influence on it.
This paper is the result of geochemistry.
[Objective] In recent years, selenium enrichment industry has developed rapidly, but because there is no significant positive correlation between selenium content in soil and selenium content in crop seeds, the planting regionalization of selenium-enriched agricultural products based on soil selenium content has certain uncertainties. Therefore, how to establish the selenium-rich model of agricultural products to predict the production area of selenium-rich agricultural products and make reasonable planning is an urgent scientific problem. [Methods] The crops and soils were collected from Zhangbei county of Hebei province. And pH, organic carbon, silica, aluminum trioxide, calcium oxide, magnesium oxide, ferric oxide, potassium oxide, sodium oxide, selenium, arsenic, mercury, cadmium, lead, copper, zinc, chromium, and nickel were measured. The influencing factors of selenium uptake in crops were studied, and the prediction model of crop selenium content based on neural network was established, and the yield area of seleniumrich crops was predicted, base on the results of measurement and the data of 1/250000 multiple geochemistry collected. [Results] There were only 2.31 percent of topsoil sites reached the standard of selenium-enriched, and they mainly distributed in the northern area of Sanhao Town. There are 6 naked oats which meet the standard of selenium-enriched, and the selenium-enriched rate is 16.67 percent. While there are 7 flaxseeds which meet the standard of selenium-enriched, and the selenium-enriched rate is 21.86 percent. There was a negative relationship between crops' bioconcentration factor for selenium with organic carbon, ferric oxide and aluminum trioxide, a positive relationship with pH in soil. The prediction model of selenium content in flax and naked oat seed was established by machine learning, and the results were reliable. The potential production areas of flax and naked oats were mainly distributed in Zhangbei, Xiaoertai, Tailugou, Youlouou and Haojiaying Town, etc, and the output areas were 2 486 km2 and 2 406 km2, respectively.[Conclusions] The area of selenium-rich crop producing area defined by the prediction model is much larger than the selenium-rich soil area, which is of great significance for the development of selenium-rich agriculture in Zhangbei County.
[Objective] Irrigation water is an important input route for elements in soil and crops, in order to identify the geochemical
characteristics of irrigation water and major crops in Dashetai area of Inner Mongolia, geochemical evaluation of irrigation water and crop quality was carried out.[Methods] A total of 30 irrigation water samples, 28 corn samples and 13 pepper samples were collected in Dashetai area during September to October of 2021. [Results] Geochemical tests were carried out, and the test results showed that the chemical type of irrigation water in the wells in the survey area was HCO3-Na · K ions are mainly derived from silicate rocks, Ca2+ and Mg2+ ions are mainly derived from the dissolution of carbonate and sulfate minerals such as calcite, dolomite and gypsum, and silicate minerals are also one of the main sources, and strong ion exchange occurs.[Conclusions] The irrigation water is alkaline, the main heavy metal elements and compounds are within the specified limits, which meet the irrigation water quality standards, combined with the evaluation indicators such as SAR, SC, PI and RSC, it is considered that the irrigation water quality in the area is better. The heavy metal content in chili pepper and corn is below the limit value specified in the standard lmit, which is at a safe level. On the whole, the Dashetai area is an excellent agricultural cultivation area.
This paper is the research on the geological disasters.
[Objective] Located in the semi-mountainous region of the Yungui Plateau, Huize County is frequently affected by geological disasters, particularly landslides. This study focused on landslide hazards, with a coupled model being employed for vulnerability assessments, aiming to develop an evaluation model tailored to the unique geographical and environmental characteristics of the semi-mountainous area of the Yungui Plateau.[Methods]Twelve evaluation factors, including topography, slope, and aspect, were carefully selected. The probability of landslide occurrence was calculated using the Coefficient of Determination (CF) and Logistic coupling model. The results were graded using the GIS-based Natural Breaks method. The model underwent rigorous validation through rationality and sensitivity tests.[Results](1) Elevation, distance to faults, distance to roads, and slope were identified as significant influencers on landslide susceptibility in Huize County. (2) The areas categorized as stable, low, moderate, and high susceptibility cover 46.25 km2 (0.61%), 3 095.41 km2 (52.77%), 1 296.64 km2 (21.94%), and 1 446.53 km2 (21.94%), respectively. (3) The Coefficient of Determination (CF) and Logistic coupling model demonstrated high rationality, with an AUC value of 0.927.[Conclusions](1) Moderate to high susceptibility landslide areas are concentrated in the southwest and northeast regions of Huize County, while low susceptibility and stable areas are prevalent in the northwest, central, and southern regions. (2) The application of the CF-Logistic coupling model for landslide vulnerability assessment exhibits superior rationality and accuracy.
This paper is the result of geothermal geology.
Geothermal is a clean energy source, and local concentrated extraction of geothermal fluid will cause a pressure depression cones. [Objective] Due to the long history of geothermal development, multiple large-scale pressure depression cones have been formed in the Tianjin area. Since 2018, the water level in the center of the cones began to rise rapidly and the thermal reservoir pressure began to recover after the gradual reduction of mining output. However, there are few studies on the correlation between the water level rise and the change of mining output, and what changes will happen to the cone shape, and the understanding of the evolution law is not clear enough. [Methods] This article takes the dynamic changes of water level in the Guantao Formation of the Neogene in Tianjin as an example, analyzes the correlation between extraction and reinjection volume and water level, studies the dynamic evolution law of water level in the cone area, analyzes the cause for pressure recovery, and provides reasonable suggestions for evaluating geothermal recoverable amount in the depression cones. [Results] The study suggests that the continuous "insufficient inflow" of thermal reservoir water is the fundamental cause for the formation of a pressure depression cone, while the combined effect of group wells pumping leads to synchronous fluctuations in thermal reservoir pressure, a sharp decrease in consumption, and the flattening effect of the cone causing the water level in the central area of the cone to rise.[Conclusions] Geothermal evaluation and management should be based on the real-time dynamics of thermal reservoir pressure in the cone area, and reasonable control of consumption and maintenance of water balance are effective ways for the sustainable utilization of geothermal resources.
This paper is the result of the evaluation of groundwater resources and analysis of geological environment problems.[Objective] In order to improve the understanding of hydrogeology and groundwater resources in Inner Mongolia inland river basin,improve the utilization efficiency of groundwater resources and reduce the geological environment problems. [Methods]Taking In‐ner Mongolia Inland River Basin as the main work area, this paper identified the drainage characteristics and hydrogeological condi‐
tions of the basin, collected and sorted out the meteorological and groundwater development and utilization data of the basin in the past 20 years, updated the hydrogeological parameters related to groundwater resource evaluation, and summarized and analyzed the drainage items of groundwater resources in the basin. The drainage method and recharge method were used to evaluate groundwater resources in hilly and plain areas. At the same time, the characteristics of groundwater dynamic change in the basin are discussed comprehensively, and the ecological and geological environment problems related to groundwater such as lake shrinking and land de‐sertification are discussed. [Results] It is calculated that the total groundwater resources in the inland river basin are 3.794 billion m3. The shallow groundwater level in the upper Bashang area generally experiences a general trend of first rising and then decreas‐ing, and the groundwater level generally presents a cyclical trend during the year. Affected by the groundwater level, the lakes in thebasin shrink seriously, the sandy desertification area decreases, and the saline-alkali desertification gradually increases.[Conclusions]This study provides basic data and scientific basis for sustainable development and utilization of water resources and ecological envi‐ronment protection in this area.
This paper is about the research on the Karst Water system.
[Objective] Karst water is the main water source of cities and towns in northern China. In this paper, the hydrogeological characteristics of the karst water system in Shenxian Mountain in Fuping are studied.The research results can provide an important reference for the rational development and utilization of karst water in Fuping. [Methods] This paper mainly takes the karst water system of Shenxian Mountain in Fuping as the research object, and systematically summarizes the hydrogeological characteristics of the karst water system in the study area by studying the geological background of karst formation, karst development characteristics,aquifer structure, groundwater circulation, and karst water chemical characteristics. [Results] The groundwater system of karst of Shenxian Mountain in Fuping is a relatively independent karst hydrologic system. Karst hydrologic system boundary consists of carbonate rock and metamorphic rock boundary ,the water separation boundary formed by water resistance fault structure and the surface underground watershed boundary. The karst water system is divided into dolomite karst fissure aquifer of Jixian system and Changcheng system and the limestone karst fissure aquifer of Ordovician-Cambrian system. The atmospheric precipitation in Shenxian Mountain area of Fuping is the main source of groundwater recharge. The atmospheric precipitation infiltrates along the cracks to recharge the groundwater. The karst groundwater in Fuping Shenxian Mountain is excreted in the form of Jinlongdong spring (underground river), with a water volume of 5382-75466 m3/d.The strontium content in the spring water is 0.58-1.28 mg/l,which reaches the limit index of ' drinking natural mineral water ' (GB 8537-2018). [Conclusions] Karst develops in ShenxianMountain area of Fuping, forming a relatively independent karst water system, and groundwater circulates in the system. It is appropriate to build underground water retaining structures near the Jinlongdong underground river to form underground karst
reservoirs, which has considerable development and utilization value.
This paper is the result of the research on the standard system of geophysical exploration technology
[Objective] As an essential technical guarantee for the development of the geological industry, the tendency of refinement and integration in exploration technical standards objectively necessitates the acceleration of digitization of existing standards to meet various demands such as rapid retrieval, analysis, comparison, splitting and reconstruction of standard technical contents.[Methods] Considering that code of practice is the standard type with the largest proportion and similar structure in exploration technical
standard system, the code of practice for magnetotelluric sounding (DZ/T 0173-2022) is taken as the research object. Refer to the tagging framwork of national standard, DZ/T 0173-2022 was structured based on extensible markup language XML. [Results] The corresponding relationship between the composition elements and the structural framework of the code of practice in exploration technical filed is established, and the structural description of basic information, auxiliary information, terminology information and technical contents of exploration technical standards was realized based on XML. It is pointed out that the structural framework suffers from deficiencies such as incomplete elements, limited descriptive dimensions and relatively coarse granularity of structured modules. [Conclusions] The research on digitization of exploration technical standards should be strengthened in the aspects of standard structural metamodel, tag set, content template and style sheet of different functional types, so as to realize the standard content structure of all elements, multi-dimension and fine granularity, laying a preliminary foundation for machine readable and transferable exploration technical standards.
This paper is the result of the research on geological information techology.
[Objective] In order to comprehensively improve the geological environment information service ability of Jilin Province and solve many problems such as scattered geological environment data storage, lack of data sharing service mechanism and weak comprehensive analysis ability, Jilin Province geological environment information data sharing and service platform was developed by adopting the concept of "big integration, big integration and big integration". [Methods] The platform takes Service-Oriented Architecture (SOA) as the overall framework. Net, Geographic Information System (GIS), Virtual Reality (VR), database and other technology support. Based on hash grid improvement of ellipsoid quadtree spatial index and slice database construction technology, SOA and WCF geological environment big data sharing and service technology, C/S and B/S mode information system integration and other key technologies. [Results] The platform highly integrates geological environment survey, monitoring and comprehensive evaluation data, standardizes the whole process of geological environment data from production, collection, integration, management, update, sharing to application, and adopts the personalized functions of work system, service system and science popularization system to enhance the professionalism and universality of geological environment data services. And based on VR technology and geological environment cross-research to improve the breadth and depth of geological environment data application.[Conclusions] The platform has greatly improved the scientific and technological innovation ability and modernization level of the transformation of geological environment achievements, and is of great significance for accurately serving geological environment investigation, monitoring, protection and geological disaster prevention.
This paper is the result of engineering geophysical exploration.
[Objective] The complex resistivity inversion parameters are four Cole-Cole model parameters, which directly increases the multisolution of complex resistivity inversion. Moreover, the sensitivity of real and imaginary parts of complex resistivity to different Cole-Cole models is different, so the ability of complex resistivity inversion is required. [Methods] In this paper, the regularization idea is introduced into the weighted inversion of the real and imaginary parts of complex resistivity, and four Cole-Cole model
parameters are inverted in four steps, and four different weighting coefficients are designed to weight the objective functions of the real and imaginary parts in the inversion of different Cole-Cole parameters, so as to control the proportion of the real and imaginary parts in the inversion. When inverting the same parameter, the inversion results of different initial models are compared, and the influence of the initial models on the inversion results is analyzed. [Results] Model test results show that this algorithm can not only improve the inversion effect of Cole-Cole model parameters, but also reduce the dependence of inversion results on the weighting coefficient and some parameters on the initial model. [Conclusions] The algorithm used in this study has effectively improved the accuracy of the inversion process for the Cole-Cole model parameters.
This paper is the result of ICP-MS.
[Objective] Rare earth elements play an important role in geochemistry, and their additive significance is also very prominent,which can be called geochemical indicators. The content of rare earth elements in rock samples was determined by ICP-MS with open acid solution - inductively, which is a common method. In order to improve the accuracy of detection of rare earth elements in rocks, the uncertainty of measurement is analyzed and evaluated from each component in the experiment.[Methods] The layer-bylayer analysis and final evaluation are established based on the source,which is the content of rare earth elements in rock samples was determined by ICP-MS with open acid solution inductively.[Results]The results showed that the combined relative standard un‐certainties ranged from 0.004 9 to 0.009 1. [Conclusions]The uncertainty of this method mainly comes from the standard solution of the sample, and the contribution value of the standard curve fitting is the largest, which is consistent with the actual test situation in the laboratory.
Office
Quarterly, started in 1987 Responsible Institution: China Geological Survey Sponsored by: Tianjin Center, China Geological Survey Published by: Editorial department of North China Geology ISSN 2097-0188 CN 12-1471/P