| 马伟,曹煜昊,董月,司明,孙通,杨淑红.辽宁桓仁普乐堡地区新元古界岩石地球化学特征及源区环境分析[J].矿产勘查,2025,16(10):2237-2248 |
| 辽宁桓仁普乐堡地区新元古界岩石地球化学特征及源区环境分析 |
| Geochemical characteristics and source region analysis of Neoproterozoic rocks in the Pulebao Area, Huanren, Liaoning Province |
| 投稿时间：2024-01-11 |
| DOI：10.20008/j.kckc.202510002 |
| 中文关键词: 新元古界 沉积岩 地球化学 物源 桓仁 |
| 英文关键词: Neoproterozoic sedimentary rock geochemistry source region Huanren |
| 基金项目:本文受辽宁省地质矿产勘查局科研项目(辽地科[2016]04号)资助。 |
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| 中文摘要: |
| 桓仁普乐堡地区新元古代地层，包括青白口系永宁组、钓鱼台组、南芬组以及南华系桥头组，各组陆源碎屑岩发育，主要岩性有砂岩、砾岩、页岩、灰岩。碎屑沉积岩的地球化学特征主要受物源区的制约，通过对该区各组岩石进行系统取样及分析测试，分析研究各组岩石地球化学特征，揭示了其风化特征、物质来源和源区背景。其中样品的化学蚀变作用指标(CIA)、成分变异指数(ICV)反映了砂岩的碎屑成分未遭受明显风化，其源区物质较新鲜是首次沉积的砂岩；样品中 SiO2含量普遍较高，，微量元素原始地幔标准化蜘蛛图显示物源是上地壳剥蚀而来，且均表现为右倾斜的 REE配分模式，δEu具明显负异常；此外，根据样品地球化学元素特征值及相关判别图解综合表明，各组地层沉积物源岩的原始物质应主要来自上地壳，以长英质岩石为主，是上地壳源区剥蚀-搬运-沉积的产物。 |
| 英文摘要: |
| The Neoproterozoic strata in the Pulebao area of Huanren comprise the Yongning, Diaoyutai, Nan.fen Formations of the Qingbaikou System, along with the Qiaotou Formation of the Nanhua System. Terrigenous clas.tic rocks are well developed in each group formation, with dominant lithology including sandstone, conglomerate,shale and limestone. The geochemical characteristics of these clastic sedimentary rocks are primarily controlled by their source region. Based on systematic sampling and analytical testing of rocks from each formation, combinedwith petrological characteristics. The Chemical Index of Alteration (CIA) and Index of Compositional Variability (ICV) indicate that the detrital components of the sandstone have not undergone significant weathering, suggestingthat the source materials were relatively fresh and represent first-cycle deposits. The samples generally show highSiO2 content. The standardized cobweb diagram of the original mantle of trace elements shows that the source iseroded from the upper crust, and all exhibit a right-inclined REE distribution patterns, with a significant negativeδEu anomalies. Furthermore, based on the geochemical element characteristic values of the samples and the relateddiscrimination diagrams, it is comprehensively indicated that the original materials of the source rocks of the sedi.ments in each formation of strata should mainly come from the upper crust, mainly feldspar rocks, which are theproducts of erosion, transportation and deposition inan upper crustal source region. |
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