| 李国利,李斌,崔春兰,董振国.鄂尔多斯盆地东北缘补连塔矿区延安组煤岩沉积古环境分析[J].矿产勘查,2024,15(12):2259-2269 |
| 鄂尔多斯盆地东北缘补连塔矿区延安组煤岩沉积古环境分析 |
| Sedimentary paleoenvironment analysis of coal and rock in Yanan Forma-tion in Bulianta mining area, northeastern margin of Ordos Basin |
| 投稿时间：2022-06-20 |
| DOI：10.20008/j.kckc.202412009 |
| 中文关键词: 侏罗系延安组 元素地球化学 物源分析 古沉积环境 地质勘查工程 |
| 英文关键词: Yanan Formation elemental geochemistry provenance analysis paleo-sedimentary environment geology survey engineering |
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| 摘要点击次数: 178 |
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| 中文摘要: |
| 延安组煤岩含有多种元素，是地质历史时期的地球化学记录，某些特定元素丰度和组合特征能够较好地反映构造背景及古沉积环境，具有指相意义。当前对补连塔矿区延安组煤岩元素特征及沉积环境的协同演化方面缺乏全面系统的研究，为了查明其含煤地层的地球化学特征和沉积环境，对该区延安组煤岩样品进行分析化验，开展地球化学、元素示踪等方面的分析和研究，结果表明:样品 K2O/Na2O-SiO2、SiO2/Al2O3-K2O/Na2O特征反映延安组物源区构造背景相对稳定，主要与活动大陆边缘—大陆岛弧相关；硅铝系(Si/Al)为 2.69、铝钛系数(Al/Ti)为 21.24，辨别延安组煤岩矿物物源以中性岩(镁铁质岩石)类为主，样品成数分变异指数(ICV)均值为 1.92，代表为首次沉积的产物；常量元素含量和比值辨别延安组含煤地层古气候温暖潮湿，古水体较为稳定，为半咸水沉积环境，沉积条件较为稳定，主要发育湖泊三角洲沉积体系，从延安组沉积早期(5#煤组)到延安组沉积晚期(1#煤组)，古气候由温湿气候转为半湿润气候，水体古盐度逐渐增加，古氧化还原环境为低位泥炭沼泽的还原环境，为有利于煤炭聚集和演化的沉积环境，沉积环境研究和恢复有助于揭示延安期聚煤规律，可为煤炭富集区预测和煤炭的高效开采提供地球化学依据。 |
| 英文摘要: |
| The Yanan Formation coal rock contains multiple elements and is a geochemical record of geologi.cal history. The abundance and combination characteristics of certain specific elements can better reflect the tec.tonic background and ancient sedimentary environment, and have indicative significance. However, there is cur.rently a lack of comprehensive and systematic research on the elemental characteristics of coal and rock in theYanan Formation of the Bulianta mining area and their synergistic evolution with sedimentary environments. In or.der to investigate the geochemical characteristics and sedimentary environment of the Yanan Formation coal bearingstrata in the Bulianta mining area, utilize analysis and testing results of samples, the geochemical characteristicsand element tracing of the Yanan Formation coal rocks in the area were analyzed and studied. The results showedthat the K2O/Na2O-SiO2 and SiO2/Al2O3-K2O/Na2O characteristics of the samples reflected the relatively stable tec.tonic background of the Yanan Formation source area, mainly related to the active continental margin continental is.land arc; The silicon aluminum ratio (Si/Al) is 2.69 and the aluminum titanium ratio (Al/Ti) is 21.24. The mineralsource of Yanan Formation coal rock is mainly neutral rock (magnesian iron rock), and the average compositionvariation index (ICV) of the sample is 1.92, representing the product of the first sedimentation; The identification ofthe content and ratio of constant elements in the coal bearing strata of the Yanan Formation indicates that the an.cient climate was warm and humid, and the ancient water bodies were relatively stable. It was a semi saline sedimen.tary environment with stable sedimentary conditions, mainly developed in the lake delta sedimentary system. Fromthe early stage of Yanan Formation sedimentation (Coal Formation 5) to the late stage of Yanan Formation sedimen.tation (Coal Formation 1), the ancient climate shifted from warm and humid climate to semi humid climate, and theancient salinity of the water gradually increased. The ancient redox environment was a reducing environment of low-level peat bogs, which is conducive to the accumulation and evolution of coal. The study and restoration of sedimen.tary environment is helpful in revealing the coal accumulation rules of the Yanan period, providing geochemical ba.sis for predicting coal enrichment areas and efficient coal mining. |
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