Fan Zhang , Yangquan Jiao , Liqun Wu , Hui Rong , Jianying Wang , Chengcheng Zhang
{"title":"富铀分散有机物的地球化学特征及其对铀矿化的地质意义:鄂尔多斯盆地案例研究","authors":"Fan Zhang , Yangquan Jiao , Liqun Wu , Hui Rong , Jianying Wang , Chengcheng Zhang","doi":"10.1016/j.gexplo.2024.107528","DOIUrl":null,"url":null,"abstract":"<div><p>Geochemical characteristics of uranium minerals is an important content for uranium deposits, and is conducive to understand the formation mechanism, environment and genesis of sandstone-type uranium deposits. In the Diantou-Shuanglong uranium deposit from southern Ordos basin, carbonaceous debris (CD), dispersed organic matter, is widely distributed in sandstones from uranium-bearing strata, and is the dominant enrichment agent for uranium precipitation. The geochemical compositions of uranium-rich CD were investigated by using inductively coupled plasma mass spectrometry (i.e., ICP-MS) and scanning electron microscope-energy dispersive X-ray spectroscopy (i.e., SEM-EDS). The results show that element U bears a close relationship with elements W, Ta, Mo, Pb, Th, Bi, Mn, V, Ti, Co, Be, especially Mo, and Pb, indicating that these elements are rich in uranium-bearing minerals. The contents of rare-earth element (i.e., REE) and light rare-earth element (i.e., LREE) increase with the increasing uranium abundance, implying that REE primarily enrich in uranium minerals, especial for LREE. Moreover, LTEE (e.g., Nd) and Y are detected in uranium-bearing minerals. Besides, uranium-bearing CD exhibits similar REE geochemical characteristics and distribution patterns with the surrounding sandstones, indicating that they are homologous in sedimentary source, sedimentary environment, and tectonic background, and the CD is deposited during synsedimentary period. Given the distribution characteristics of trace element and REE, it is comprehensively inferred that the formation of uranium mineralization is not related to deep hydrothermal fluid below the lower crust, but is altered by the low-temperature hydrothermal fluid. Synsedimentary CD at the stage of low to medium thermal maturity is of certain adsorption and reduction, and is favorable for the precipitation and enrichment of uranium-bearing phase and the other trace element (e.g., Mo, V) similar in geophysical-chemical properties with U element, and the sedimentary environment is beneficial for preservation of uranium. It will be contributed to clarify the genesis of sandstone-type uranium deposit and to provide some guidance for the exploration of the uranium deposit in the studied area.</p></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":null,"pages":null},"PeriodicalIF":3.4000,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Geochemical characteristics of uranium-rich dispersed organic matter and their geological significance for uranium mineralization: A case study from the Ordos Basin\",\"authors\":\"Fan Zhang , Yangquan Jiao , Liqun Wu , Hui Rong , Jianying Wang , Chengcheng Zhang\",\"doi\":\"10.1016/j.gexplo.2024.107528\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Geochemical characteristics of uranium minerals is an important content for uranium deposits, and is conducive to understand the formation mechanism, environment and genesis of sandstone-type uranium deposits. In the Diantou-Shuanglong uranium deposit from southern Ordos basin, carbonaceous debris (CD), dispersed organic matter, is widely distributed in sandstones from uranium-bearing strata, and is the dominant enrichment agent for uranium precipitation. The geochemical compositions of uranium-rich CD were investigated by using inductively coupled plasma mass spectrometry (i.e., ICP-MS) and scanning electron microscope-energy dispersive X-ray spectroscopy (i.e., SEM-EDS). The results show that element U bears a close relationship with elements W, Ta, Mo, Pb, Th, Bi, Mn, V, Ti, Co, Be, especially Mo, and Pb, indicating that these elements are rich in uranium-bearing minerals. The contents of rare-earth element (i.e., REE) and light rare-earth element (i.e., LREE) increase with the increasing uranium abundance, implying that REE primarily enrich in uranium minerals, especial for LREE. Moreover, LTEE (e.g., Nd) and Y are detected in uranium-bearing minerals. Besides, uranium-bearing CD exhibits similar REE geochemical characteristics and distribution patterns with the surrounding sandstones, indicating that they are homologous in sedimentary source, sedimentary environment, and tectonic background, and the CD is deposited during synsedimentary period. Given the distribution characteristics of trace element and REE, it is comprehensively inferred that the formation of uranium mineralization is not related to deep hydrothermal fluid below the lower crust, but is altered by the low-temperature hydrothermal fluid. Synsedimentary CD at the stage of low to medium thermal maturity is of certain adsorption and reduction, and is favorable for the precipitation and enrichment of uranium-bearing phase and the other trace element (e.g., Mo, V) similar in geophysical-chemical properties with U element, and the sedimentary environment is beneficial for preservation of uranium. It will be contributed to clarify the genesis of sandstone-type uranium deposit and to provide some guidance for the exploration of the uranium deposit in the studied area.</p></div>\",\"PeriodicalId\":16336,\"journal\":{\"name\":\"Journal of Geochemical Exploration\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.4000,\"publicationDate\":\"2024-06-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Geochemical Exploration\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0375674224001444\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geochemical Exploration","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0375674224001444","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
摘要
铀矿物的地球化学特征是铀矿床的重要内容,有利于了解砂岩型铀矿床的形成机理、环境和成因。在鄂尔多斯盆地南部的店头-双龙铀矿床中,含铀地层砂岩中广泛分布着碳质碎屑(CD)这种分散的有机质,是铀沉淀的主要富集剂。利用电感耦合等离子体质谱法(即 ICP-MS)和扫描电子显微镜-能量色散 X 射线光谱法(即 SEM-EDS)研究了富铀 CD 的地球化学成分。结果表明,铀元素与 W、Ta、Mo、Pb、Th、Bi、Mn、V、Ti、Co、Be(特别是 Mo)和 Pb 元素关系密切,表明含铀矿物中富含这些元素。稀土元素(即 REE)和轻稀土元素(即 LREE)的含量随着铀丰度的增加而增加,这意味着 REE 主要富集在铀矿物中,尤其是 LREE。此外,在含铀矿物中还检测到 LTEE(如 Nd)和 Y。此外,含铀 CD 与周围砂岩表现出相似的 REE 地球化学特征和分布模式,表明它们在沉积来源、沉积环境和构造背景方面具有同源性,CD 沉积于合沉积时期。根据微量元素和稀土元素的分布特征,综合推断铀矿化的形成与下地壳深部热液无关,而是受到低温热液的改变。中低热成熟阶段的合成沉积CD具有一定的吸附性和还原性,有利于含铀相及与铀元素地球物理化学性质相似的其他微量元素(如钼、钒等)的沉淀和富集,沉积环境有利于铀元素的保存。这将有助于澄清砂岩型铀矿床的成因,并为研究区域的铀矿床勘探提供一定的指导。
Geochemical characteristics of uranium-rich dispersed organic matter and their geological significance for uranium mineralization: A case study from the Ordos Basin
Geochemical characteristics of uranium minerals is an important content for uranium deposits, and is conducive to understand the formation mechanism, environment and genesis of sandstone-type uranium deposits. In the Diantou-Shuanglong uranium deposit from southern Ordos basin, carbonaceous debris (CD), dispersed organic matter, is widely distributed in sandstones from uranium-bearing strata, and is the dominant enrichment agent for uranium precipitation. The geochemical compositions of uranium-rich CD were investigated by using inductively coupled plasma mass spectrometry (i.e., ICP-MS) and scanning electron microscope-energy dispersive X-ray spectroscopy (i.e., SEM-EDS). The results show that element U bears a close relationship with elements W, Ta, Mo, Pb, Th, Bi, Mn, V, Ti, Co, Be, especially Mo, and Pb, indicating that these elements are rich in uranium-bearing minerals. The contents of rare-earth element (i.e., REE) and light rare-earth element (i.e., LREE) increase with the increasing uranium abundance, implying that REE primarily enrich in uranium minerals, especial for LREE. Moreover, LTEE (e.g., Nd) and Y are detected in uranium-bearing minerals. Besides, uranium-bearing CD exhibits similar REE geochemical characteristics and distribution patterns with the surrounding sandstones, indicating that they are homologous in sedimentary source, sedimentary environment, and tectonic background, and the CD is deposited during synsedimentary period. Given the distribution characteristics of trace element and REE, it is comprehensively inferred that the formation of uranium mineralization is not related to deep hydrothermal fluid below the lower crust, but is altered by the low-temperature hydrothermal fluid. Synsedimentary CD at the stage of low to medium thermal maturity is of certain adsorption and reduction, and is favorable for the precipitation and enrichment of uranium-bearing phase and the other trace element (e.g., Mo, V) similar in geophysical-chemical properties with U element, and the sedimentary environment is beneficial for preservation of uranium. It will be contributed to clarify the genesis of sandstone-type uranium deposit and to provide some guidance for the exploration of the uranium deposit in the studied area.
期刊介绍:
Journal of Geochemical Exploration is mostly dedicated to publication of original studies in exploration and environmental geochemistry and related topics.
Contributions considered of prevalent interest for the journal include researches based on the application of innovative methods to:
define the genesis and the evolution of mineral deposits including transfer of elements in large-scale mineralized areas.
analyze complex systems at the boundaries between bio-geochemistry, metal transport and mineral accumulation.
evaluate effects of historical mining activities on the surface environment.
trace pollutant sources and define their fate and transport models in the near-surface and surface environments involving solid, fluid and aerial matrices.
assess and quantify natural and technogenic radioactivity in the environment.
determine geochemical anomalies and set baseline reference values using compositional data analysis, multivariate statistics and geo-spatial analysis.
assess the impacts of anthropogenic contamination on ecosystems and human health at local and regional scale to prioritize and classify risks through deterministic and stochastic approaches.
Papers dedicated to the presentation of newly developed methods in analytical geochemistry to be applied in the field or in laboratory are also within the topics of interest for the journal.