东道海子凹陷下侏罗统物源分析—来自岩石学、元素地球化学及碎屑锆石年代学的证据
- 收稿日期:
2024-05-16
- 网络出版日期:
2024-11-06
摘要: 摘 要【目的】准噶尔盆地东道海子凹陷下侏罗统八道湾组和三工河组的物源组成及演化对源区克拉美丽造山带早侏罗世构造活动具有重要的指示意义。【方法】基于砂岩碎屑组成、稀土元素及碎屑锆石U-Pb年龄特征，对八道湾组和三工河组物源特征及演化过程进行了分析。【结果】结果显示，研究区下侏罗统砂岩以长石质岩屑砂岩为主，薄片中岩屑平均含量37.7%，以凝灰岩岩屑、玄武岩岩屑为主，少量变质岩岩屑；八道湾组表现出轻、重稀土分异并不明显的特征，而三工河组为轻微的轻稀土富集、重稀土亏损的特征；八道湾组碎屑锆石年龄主要集中在二叠纪、泥盆纪，而三工河组则以石炭纪为主，年龄组成上存在明显差异。【结论】综合物源特征分析认为，东道海子凹陷下侏罗统物源区母岩以中-酸性岩浆岩及基性岩浆岩为主，大地构造背景主要为再循环造山带的过渡再旋回带，与东部克拉美丽造山带的洋-陆俯冲形成的混杂物源以及洋盆关闭后克拉美丽造山带较为一致。东道海子凹陷八道湾组至三工河组的物源经历了以洋壳俯冲物源为主转变为以石炭纪洋陆闭合物源为主的转变，对克拉美丽造山带早侏罗世不断增强的隆升过程具有良好的响应关系，指示了克拉美丽造山带早侏罗世持续隆升，差异剥蚀的过程。
Provenance Analysis of Lower Jurassic in Dongdao Haizi Sag—Evidence from petrology, elemental geochemistry, and detrital zircon chronology
- Received Date:
2024-05-16
- Available Online:
2024-11-06
Abstract: Abstract: [Objective] The provenance composition and evolution of the Lower Jurassic Badaowan Formation and Sangonghe Formation in the Dongdaohaizi Sag of the Junggar Basin are of great significance for the early Jurassic tectonic activity of the Karamaili orogenic belt in the provenance area. [Methods] Based on the composition of sandstone clasts, rare earth elements and detrital zircon U-Pb ages, the provenance characteristics and evolution process of the Badaowan Formation and Sangonghe Formation were analyzed. [Results] The results show that the Lower Jurassic sandstone in the study area is dominated by with an average content of 37.7% of rock fragments in thin sections, mainly tuff fragments and basalt fragments, and a small amount of metamorphic rock fragments.The Badaowan Formation shows no obvious differentiation between light (LREE) and heavy rare earth (HREE), while the Sangonghe Formation has the characteristics of slight LREE enrichment and HREE loss, and the age of detrital zircons in the Badaowan Formation mainly falls in the Permian and Devonian periods, while the age data of the Sangonghe Formation is mainly from the Carboniferous period, and there are obvious differences in age composition.[Conclusion] The analysis by synthesis of provenance characteristics, the parent rocks in the Lower Jurassic source area of the Dongdaohaizi Sag are dominated by medium-acid magmatic rocks and mafic magmatic rocks, and the tectonic background is mainly the transitional recycled zone of the recirculating orogenic belt, which is consistent with the mixed source formed by ocean-land subduction in the eastern Karamaili orogenic belt and the Karamaili orogenic belt after the closure of the ocean basin. The provenance of the Badaowan Formation to the Sangonghe Formation in the Dongdaohaizi Sag has undergone a conversion from the main source of oceanic crustal subduction to the closed source of the Carboniferous ocean-land, which has a good response to the increasing uplift process of the Early Jurassic of the Karamaili Orogenic Belt, indicating the continuous uplift and differential denudation process of the Early Jurassic of the Karamaili Orogenic Belt.
朱雪清, 刘圣乾, 朱青, 刘彬, 曾治平, 李松涛, 高杨骏. 东道海子凹陷下侏罗统物源分析—来自岩石学、元素地球化学及碎屑锆石年代学的证据[J]. 沉积学报. doi: 10.14027/j.issn.1000-0550.2024.104
Provenance Analysis of Lower Jurassic in Dongdao Haizi Sag—Evidence from petrology, elemental geochemistry, and detrital zircon chronology[J]. Acta Sedimentologica Sinica. doi: 10.14027/j.issn.1000-0550.2024.104
| Citation: |
Provenance Analysis of Lower Jurassic in Dongdao Haizi Sag—Evidence from petrology, elemental geochemistry, and detrital zircon chronology[J]. Acta Sedimentologica Sinica. doi: 10.14027/j.issn.1000-0550.2024.104
|
点击查看大图
下载:
