30 December 2022, Volume 45 Issue 4

    

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The 60th Anniversary Special Issue（Geological Science and Technology Innovation Album）
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  Geochemical characteristics of basalts in the northeastern Ordos Basin

  CHEN Yin, LUO Ning, CHEN Lu-lu, MIAO Pei-sen, LI Jian-guo, ZHAO Hua-lei, LI Jian-min

  North China Geology. 2022, 45(4): 1-9. https://doi.org/10.19948/j.12-1471/P.2022.04.01

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  The Cretaceous is the significant transition stage for the tectonic evolution of China. As the basin with multiple energy resources, the research on the Cretaceous intrusions in the Ordos Basin has supplied the important evidences for the tectono-thermal evolution of the western part of the North China Craton. In this work, the Hangjinqi Heishitougou basalt in the Early Cretaceous successions and Yulin Daliuta basalt in the Middle Jurassic successions in the northeastern Ordos Basin are taken as the research objects. For these rocks, their geochemical characteristics was analyzed and the regional dynamic background was further discussed. The analysis of major elements shows that the Hangjinqi Heitongshigou basalt belongs to the series of potassium basalt. Yulin Daliuta basalt belongs to the low potassium (Tholeiitic) series. The characteristics of trace and rare earth elements are right-inclined with a low grade fractionation of light REE/ heavy REE. Heidonggou basalt is regarded to come from the enriched mantle without crustal mixing. While, the Daliuta basalt has the characteristics of active continental margin with crustal mixing. Regional dynamic background analysis indicates that the deep residual body under the oblique subduction of the paleo-Pacific plate caused the instability of the deep lithosphere in the eastern margin of the western North China Craton (Ordos) and the Daxing'anling-Taihang Gravity Gradient Belt. The development of basalts in the northeastern and adjacent areas of the Ordos Basin were believed to be the result of these tectono-thermal activities. 
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  Petrology and mineralogy characteristics of the Uranium-bearing Sandstone from Sifantai Formation in Sanzhao Depression of Northern Songliao Basin and their geological implications

  CHEN Lu-lu, LI Ming, TANG Chao, HE Jing, CHEN Yin, ZHAO Hua-lei, TANG Li

  North China Geology. 2022, 45(4): 10-20. https://doi.org/10.19948/j.12-1471/P.2022.04.02

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  The study area is located in the southwest of Sanzhao Depression in northern Songliao Basin. The sandbody from the lower member of Sifantai Formation in Late Cretaceous is the metallogenic host rock. By means of the rock-mineral determination of the casting thin sections, the analysis of electron probe, X-diffraction, and scanning electron microscope, the paper has further refined and detailed studied the characteristics of petrology and mineralogy. And it has made some discussion about the provenance of source region and occurrence form of uranium. The results show that the type of uraniferous sandstone is mainly feldspathic litharenite. The debris is mainly igneous debris mainly composed of eruptive rocks and cryptocrystalline rocks, metamorphic debris mainly composed of quartzite, slate and hypermetamorphic rocks, and a small amount of sedimentary debris and tuff debris. Clastic component displays that the provenance of study area is likely to come from the Zhangguangcai mountains and the southwest of Songliao basin, where develop the Archaean-Proterozoic metamorphic series and Mesozoic volcanic rocks and granites. Electron probe analysis and backscatter images show that uranium minerals are mainly coffinite and a small amount of pitchblende. In addition to uranium mineralization, the alteration of minerals mainly includes pyritization, carbonation, ilmenite alteration, biotite alteration and clay alteration in the study area. The main mineral closely associated with uranium is early pyrite. The mineral alteration sequence roughly reflects an oxidized to reductive, acidic to alkaline environment during the sedimentary and diagenetic stages. The sandstone-type uranium deposit in this area is the result of superposition and reformation on the basis of pre-enrichment of early sedimentation.
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  Preliminary study on the occurrence state of uranium in the Lower Cretaceous Luohe Formation of Pengyang uranium deposit , southwestern Ordos Basin

  ZHAO Hua-lei, ZANG Yong-liang, LI Jian-guo, ZHANG Bo, CHEN Lu-lu, MIAO Pei-sen, LIU Xiao-jie

  North China Geology. 2022, 45(4): 21-27. https://doi.org/10.19948/j.12-1471/P.2022.04.03

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  The Pengyang uranium deposit is located in the south of Tianhuan Depression in Ordos Basin, which is the first large-scaled sandstone-type uranium deposit discovered in aeolian sediments in China. The uranium-bearing rock series occurred in the Lower Cretaceous Luohe Formation, which is dominated by desert facies, with some alluvial fan and fluvial facies sediments in the marginal area of the basin. Uranium ore bodies mainly occur in the eolian sandstone of Luohe Formation and subordinately develop in conglomerate. On the basis of field geological survey, this paper conducts preliminary research on petrological characteristics, mineral paragenesis and uranium occurrence state through the methods of thin section identification, scanning electron microscopy, energy spectrum analysis, and sequential chemical extraction. The results show that most of the uranium minerals are pitblende and the associated minerals are mainly new components such as anatase, pyrite, apatite and clay minerals. A small amount of uranium minerals also occur in the edge or fracture of primary particles. Sequential chemical extraction results show that the occurrence of uranium in the Pengyang uranium deposit is mainly carbonate state, residual state, sulfide-organic matter state, among which the average content of uranium in the form of uranium minerals is about 3/4, and the content of uranium in adsorbed form is about 1/4. These researches provide basic data for the study of uranium enrichment and the application of in-situ leaching mining.
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  Analysis and comparative research on metallogenic geological characteristics of sandstone-type uranium deposits between Zhiluo Formation and Luohe Formation in Ordos Basin

  ZHU Qiang, WU Yue, WEN Si-bo, WANG Yu, LI Guang-yao, Si Qing-hong, Zhao Hua-lei

  North China Geology. 2022, 45(4): 28-37. https://doi.org/10.19948/j.12-1471/P.2022.04.04

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  Ordos basin is rich in sandstone type uranium resources, according to the different deposit positions of the ore body, they are mainly divided into two types: one type of uranium is exist in the shallow slope belt at the edge of the basin, and the other type is exist in the inner part of the basin. The Tarangol uranium deposit in the northeastern part of the Ordos Basin is located at the edge of the basin, uranium bearing rock seriesis Zhiluo formation of Middle Jurassic, the lower member of Zhiluo formation is braided fluvial-braided fluvial delta sedimentary system, the orebody is buried shallowly, and it exists in the transitional part of gray sandstone and grayish-green sandstone in the lower sub-member of the Zhiluo formation, which is biased towards the side of the gray sandstone, and the spatial distribution is stratiform, the content of pyrite, carbon chips and acidolysis hydrocarbon is high, the sources of reducing fluids include Paleozoic natural gas (oil) and coal seams of the Yan'an Formation,. The primary type of uranium minerals is coffinite and the second type is titanium bearing uranium mineral and pitchblende. The Zhenyuan uranium deposit in the southwestern part of Ordos basin is located inside the basin, uranium bearing rock seriesis the Luohe formation of lower Cretaceous, Luohe formation is eolian sedimentary system, the ore body is deeply buried, and it is exist at the contact part of the red or yellow fine sandstones and light gray fine sandstones, which is more inclined to the light gray fine sandstone side, the spatial shape of the ore body is stratiform, approximate stratiform and lenticular, without carbon dust, pyrite and acidolysis hydrocarbon are only locally enriched near the ore body, apatite is abundant and closely related to uranium minerals, the source of reducing fluid is Yanchang formation of Upper Triassic, uranium minerals are mainly pitchblende and titanium bearing uranium minerals. Based on the comparison of the geological characteristics for sandstone type uranium mineralization between Zhiluo formation and Luohe formation in Ordos basin, the main controlling factors restricting the enrichment of the two important uranium bearing rock series and the spatial positioning of the ore body are proposed, and the ore-controlling mechanism models of uranium-bearing rock series are preliminarily established.
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  Geological characteristics and prospecting factors of sandstone type uranium deposits in Baiyanhua area, Western Erlian Basin

  LI Tong, YU Reng-an, YANG Tong-xu, SI Qing-hong, ZHU Qiang, PENG Sheng-long

  North China Geology. 2022, 45(4): 38-47. https://doi.org/10.19948/j.12-1471/P.2022.04.05

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  Baiyanhua uranium deposit is a new prospecting area in Chuanjing depression of Erlian basin in recent years. Through the screening of radioactive anomaly boreholes and the interpretation of geophysical and geochemical remote comprehensive information in the coalfield, the favorable metallogenic areas were delineated, and the industrial uranium ore bodies were discovered through drilling. The ore body is distributed in a nearly northwest direction on the plane. The initial control length of the borehole is 6.5 km, the width is 200~800 m, and the occurrence is gentle. The uranium ore body is mainly hosted in the sandstone of the Saihan Formation of the Lower Cretaceous, mainly in flat plate shape, and the ore is relatively loose. The occurrence form of uranium is mainly adsorbed uranium, and the uranium mineral is mainly uranium ore, which occurs in the fillings of mineralized sandstone and in the cleavage of clastic materials or minerals, replacing pyrite, carbon chips, etc; Partially dispersed uranium minerals are adsorbed by clay minerals, detritus and mineral particle surfaces or fracture surfaces in sandstone fillings. The main alteration types in the mining area include limonitization, hematite mineralization, kaolinization, chloritization and carbonation. The geochemical characteristics of ore bearing rocks are characterized by depletion of high field strength elements and heavy rare earth elements, obvious differentiation of light and heavy rare earth elements, and obvious negative anomaly of Eu. Uranium ore bodies are closely related to the formation of structures and sedimentary systems in the depression, and a variety of favorable metallogenic conditions are coupled to each other to enrich and mineralization. This understanding deepens the metallogenic understanding of Chuanjing Depression in Erlian Basin, and provides a theoretical basis for the next work deployment.
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  Optimization of experimental conditions for melting decomposition of zircon sands by lithium metaborate

  WANG Jia-song, WANG Li-qiang, WANG Na, FANG Peng-da, ZENG Jiang-ping, ZHANG Li-juan

  North China Geology. 2022, 45(4): 48-52. https://doi.org/10.19948/j.12-1471/P.2022.04.06

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  Lithium metborate is widely used in alkaline fusion decomposition of geological samples. At present, the experimental conditions of fusion decomposition of geological samples by lithium metaborate are quite different. Moreover, the optimization of experimental conditions is not comprehensive enough in the study of zircon sands. The fusion temperature and time and the extraction method of frit, the amount of complexing agent and the acidity of extraction were not involved. In this paper, the best experimental conditions for the decomposition of zircon sands by lithium metaborate were obtained through a series of experiments. The platinum crucible was used as fusing vessel, the dosage of lithium metapborate was 0.5 g (the dosage of sample was 0.1 g), the fusing temperature was 950 ℃, the fusing time was 15 min, the extraction method was quenching + ultrasonic oscillation, and the extraction solution was (2+8) hydrochloric acid solution containing 10g/L tartaric acid. Combined with ICP-OES to determine zirconium, hafnium, potassium, calcium, sodium, magnesium, aluminum, iron, titanium and manganese in zircon sands, The relative error (RE) and relative standard deviation (RSD) of elements of this method were ≤4.00% and ≤5.17%, respectively. The results show that this method is suitable for quantitative analysis of petrogenetic elements and ore-forming elements in zircon sands.
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  In situ U-Pb dating of titanite by laser ablation-inductively coupled plasma-mass spectrometry#br#

  CUI Yu-rong, TU Jia-run, LI Guo-zhan, ZHOU Hong-ying, GENG Jian-zhen

  North China Geology. 2022, 45(4): 53-59. https://doi.org/10.19948/j.12-1471/P.2022.04.07

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  Characterized by rich U, Th and low initial Pb content, titanite is an ideal object for U-Pb dating. For the relative high U-Pb system closure temperature and ubiquity in various rocks, titanite has enormous promise in U-Pb dating application. In this paper, combined use of 193nm excimer laser ablation system and Agilent7900 quadrupole inductively coupled plasma mass spectrometer (Q-ICP-MS) was applied for dating of titanite standard samples including MKED1、OLT1. Through systematically optimizing the parameters of beam spot diameter, laser frequency and energy density involved in the dating of titanite, the results show that LA-ICP-MS U-Pb dating of titanite was insensitive to beam spot diameter (~1 %), laser frequency and energy density (<3 %). Therefore, in LA-ICP-MS U-Pb dating of titanite, the best laser ablation conditions are 43 μm, 8 Hz, 3 J/cm2 or 51 μm, 8 Hz, 3 J/cm2. Furthermore, the LA-ICP-MS U-Pb dating technique of titanite was established and successfully applied to the Lazigou gold deposit in the Mouru metallogenic belt, verifying its age of late Jurassic. This research has shown the potentials of titanite U-Pb dating and further expanded the application of the method.
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  The study of land desertification recognition and extraction based on hyperspectral satellite data

  WANG Jian-hua, LI-yang, LIANG Shu-neng , SUN Xiao-fei

  North China Geology. 2022, 45(4): 60-67. https://doi.org/10.19948/j.12-1471/P.2022.04.08

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  Study area is located in the sediment-rock region of the middle Yellow River basin, which is the transition zone between the Mu Us sand land and the Hilly Loess region; The coarse sediment of the Yellow River mainly originates from this area which is also one of the areas with serious erosion on the Loess Plateau. With the development of remote sensing technology, hyperspectral remote sensing provides a new method for global and regional land desertification research, and land desertification monitoring is developing towards quantitative remote sensing. This paper uses the advantages of hyperspectral data to retrieve the vegetation coverage, bare soil index, surface albedo and improved soil adjusted vegetation index. Based on the hyperspectral data of ZY-1 02D satellite, these four indicators are taken as the comprehensive monitoring indicators of land desertification. Through the human-computer interactive interpretation of the land desertification degree in study area. The remote sensing interpretation signs of land desertification in typical areas of the middle Yellow River basin have been established, and the monitoring results have been taken as reference data. The decision tree classification model for the study area has been established to realize the recognition, extraction and evaluation of land desertification. The data have been checked by visual methods and receiver operation characteristic curves, and the results show that there is a significant match, and the method based on decision tree classification model is more detailed than the human-computer interactive interpretation method.
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  Study on evaluation index system of suitability for development and utilization of underground space in sedimentary plain: A Case Study of Tongzhou District in Beijing and Langfang north three counties in Hebei Province

  LIU Hong-wei, WANG Guo-ming, MA Chuan-ming, GAO Ming-da, BAI Yao-nan, ZHANG Jing, DU Dong

  North China Geology. 2022, 45(4): 68-74. https://doi.org/10.19948/j.12-1471/P.2022.04.09

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  Based on the geological environment conditions of the Tongzhou District of Beijing and Langfang north three counties of Hebei province, this paper evaluates the suitability of the development and utilization of the shallow(0~-18m), medium(-22~-50 m) and deep(Below-70 m) underground space at different depths in this area according to the four levels of unsuitable, less appropriate, more appropriate and appropriate by the analytic hierarchy process. The results show that more than 70% of the study area is suitable or more suitable for the development and utilization of underground space. Among them, the suitable area for shallow underground space development accounts for 32.44%, the more suitable area accounts for 42.46%, the less suitable area accounts for 17.03%, and the unsuitable area accounts for 8.07%; The middle suitable area accounts for 13.75%, the more suitable area accounts for 57.15%, and the less suitable area accounts for 19.89%, the proportion of unsuitable areas is 9.21%; The deep suitable area accounts for 39.74%, the more suitable area accounts for 40.37%, and the less suitable area accounts for 11.63%, the proportion of unsuitable areas is 8.25%. The evaluation results can provide geoscientific basis for the planning of underground space development and utilization in the study area.
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  Design and implementation of integrated framework for field data collection in geological survey

  REN Wen-qian, LIU Yuan-yuan

  North China Geology. 2022, 45(4): 75-79. https://doi.org/10.19948/j.12-1471/P.2022.04.10

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  With the continuous advancement of geological survey informatization, the application software of various field data acquisition apps of geological survey is increasing. However, the field project team finds many limitations in the field application process, especially when carrying out multi-professional comprehensive business investigation, and the demand for the integrated management of field data acquisition APP is increasing. Based on the cloud environment, this paper uses technologies such as Vue, Spring Boot framework and MySQL database to build an integrated framework of geological survey field data acquisition apps that separate the front and back ends, and develops Web and mobile application tools for support. Unified APP management, version control and permission allocation are realized on the web side, and customized APP configuration, on-demand installation and unified login are realized on the mobile side, which improves the convenience of APP use for field geological survey personnel.
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  The petrological, geochemical characteristics and tectonic significance of Changsheshan Gabbro rock in Qiangtang, Tibet

  YANG Hu, WANG Gen-hou, LI Hong-wei, LUO Tao

  North China Geology. 2022, 45(4): 80-90. https://doi.org/10.19948/j.12-1471/P.2022.04.11

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  Based on the petrology, mineralogy, geochemistry and chronology, such as research methods, and combining previous research results, a detailed analysis of the NW-SE gabbro structure in the changsheshan area, qiangtang, Tibet, shows that the gabbro in this area originated from the continental crust environment and was mixed with other materials during the magmatic evolution. this is different from the mid-ocean ridge environment produced by the E-W basic intrusive rocks in the area where changshe mountain is located -- Mayigangri area. Therefore, it is speculated that the wall group in this study area was formed in the germination stage of Wilson cycle, The initial rift environment formed under the background of continental extension is an important constraint on the tectonic evolution of Longmuco-double lake suture zone, and helps to deepen the understanding of the foreign evolution of Tethys.