| 准噶尔盆地东部双井子地区上石炭统泥岩地球化学特征及其地质意义 |
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| 引用本文： | 邓敏,程锦翔,唐勇,付国斌,王正和,冯伟明,李嵘.准噶尔盆地东部双井子地区上石炭统泥岩地球化学特征及其地质意义[J].地质论评,2024,70(2):2024020016-2024020016. |
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| 作者姓名： | 邓敏 程锦翔 唐勇 付国斌 王正和 冯伟明 李嵘 |
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| 作者单位： | 1）中国地质调查局成都地质调查中心（西南地质科技创新中心），成都，610218；2）自然资源部沉积盆地与油气资源重点实验室，成都，610218;3）中国石油新疆油田分公司，新疆克拉玛依，834000;4）中国石油吐哈油田分公司，新疆哈密，839000 |
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| 基金项目： | 本文为自然资源部深时地理环境重建与应用重点实验室开放基金资助项目（编号：DGERA20231108）的成果 |
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| 摘 要： | 准噶尔盆地东部石钱滩凹陷石炭系巴塔玛依内山组火山岩之后发育一套连续稳定的碎屑岩沉积。笔者等通过XRD、主微量元素分析等手段针对其中的细粒沉积岩开展元素地球化学研究，其结果对恢复准东地区晚石炭世源区风化特征、古气候、判断其源岩性质及源区构造背景具有重要意义。研究表明，巴山组—石钱滩组泥岩具有低石英含量特点，其中巴山组泥岩黏土含量稍高，而石钱滩组泥岩中长石含量高，两者黏土成份均为蒙脱石（>99%），反映了干燥、寒冷的气候特征且沉积介质长期为碱性；CIA结果显示巴山组—石钱滩组时期经历了中等—弱化学风化作用，并具有干湿交替气候变化特征；主微量元素及相关判别图解显示巴山组—石钱滩组泥岩的源岩多以偏中性的长英质火山岩为主，少量中基性及少量偏酸性的火山岩物源，并且多数为未分异的弧；泥岩的地球化学特征反映了沉积物源区构造背景主要为大陆岛弧背景，结合石钱滩组碎屑锆石峰值年龄及主要物源区分析认为，野马泉地体与其南部的准噶尔地体东北缘于335 Ma左右开始由俯冲转变为碰撞造山。
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| 关 键 词： | 准噶尔盆地东部 石炭系 源岩性质 古气候 构造背景 地球化学特征 |
| 收稿时间： | 2024/1/15 0:00:00 |
| 修稿时间： | 2024/4/2 0:00:00 |
Geochemical characteristics and its geological significance of upper Carboniferous mudstone in Shuangjingzi area, Eastern Junggar Basin, Xinjiang |
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| DENG Min,CHENG jinxiang,Tang yong,Fu guobin,WANG zhenghe,FENG weiming,LI rong.Geochemical characteristics and its geological significance of upper Carboniferous mudstone in Shuangjingzi area, Eastern Junggar Basin, Xinjiang[J].Geological Review,2024,70(2):2024020016-2024020016. |
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| Authors: | DENG Min CHENG jinxiang Tang yong Fu guobin WANG zhenghe FENG weiming LI rong |
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| Abstract: | A set of continuous and stable clastic deposits rock developed after volcanic rocks of the Batamayneishan Formation in Shiqiantan sag, Eastern Junggar Basin. The study of the Upper Carboniferous mudstones are of great significance for restoring the weathering characteristics and paleoclimate of the late Carboniferous source area in Eastern Junggar and judging the properties and tectonic setting of the source rocks.Methods: In order to systematically study the whole-rock geochemistry of the fine-grained sedimentary rocks, the author have combined with the XRD, major and trace element results of the outcrop samples.Results: Mudstones from the Upper Carboniferous mudstones are all have low quartz contents. The Batamayneishan Formation mudstones have high clay contents, whereas those of the Shiqiantan Formation have high andesine contents. The clay compositions both of them are montmorillonites (content>99%), reflecting dry and cold climate characteristics and long-term alkaline deposition medium conditions. The CIA results show that the Batamayneishan and Shiqiantan Formations experienced moderate to weak chemical weathering and had the characteristic of alternating dry and wet climate change. The major trace elements and related discriminant diagrams shows that the provenance of tow formations are dominated by felsic, mixed with a few meso-mafic and acidic sources, and most of them come from undifferentiated arcs. The element-geochemical characteristics of the mudstones reflect that the tectonic background of the provenance is mainly the continental island arc.Conclusions: Combined with the peak age of detrital zircon in Shiqiantan Formation and the analysis of the main provenance area, it is concluded that the Yemaquan terrane and the northeastern Junggar terrane began to change from subduction to collision orogeny around 335 Ma. |
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| Keywords: | Eastern Junggar Basin Carboniferous provenance paleoclimate tectonic setting geochemical characteristics |
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