...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of African Earth Sciences >Mineralogical and geochemical characterization of the unconsolidated sands from the Mefou River terrace, Yaounde area, Southern Cameroon
【24h】

Mineralogical and geochemical characterization of the unconsolidated sands from the Mefou River terrace, Yaounde area, Southern Cameroon

机译：喀麦隆南部雅温得地区Mefou河阶地未固结砂的矿物学和地球化学特征

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Nine sediment core samples from the right terrace of the Mefou River in the Yaounde area (southern Cameroon) were used to investigate the provenance and evolution of sediments. The mineralogical and geochemical data have been reported using XRD, XRF and ICP-MS instruments. The sediment core is 87 cm thick and is subdivided from the bottom to the top into sandy, clayey sandy and, silty sandy layers. The sandy layer is 70 cm thick with a decreasing grain size from the bottom to the top. The nine sediment core samples are mainly composed of quartz, and accessory feldspars, kaolinite, goethite, rutile and muscovite/Mite. This mineral assemblage can be explained by the combined effect of metamorphic source rocks and surrounding soils. The sandy texture as well as the abundance of quartz were confirmed by the high SiO2 contents particularly at the bottom of the sequence (71-85 wt%). The high SiO2/Al2O3, low alkali (Na2O + K2O) values, low REE contents (similar to 107-389 ppm; avg. = 247 ppm) and the negative correlation between SiO2 with most of major and trace elements confirm the siliciclastic nature of sediments. The SiO2/Al2O3 ratio justifies the high proportion of quartz relative to clay minerals and the coarse grain size of the sediments. The Mefou alluvial sediments are classified as Fe-shale and Fe-sand. The LREE/HREE ratio and (La/Yb)(N) values exhibit the light REE-abundance linked to the nature of REE mineral-bearers. The spider diagrams reveal the high depletion of K and Sr due to the high feldspar alteration and the quartz-abundance. The REE-normalization relative to chondrite portrays slightly positive Ce anomalies (Ce/Ce*similar to 1.11-1.15) and negative Eu anomalies (Eu/Eu*similar to 0.43-0.63).The mineralogical and geochemical features are in concordance with the textural parameters and portray the siliciclastic nature of sediments inherited from the gneiss basement. The predominance of sands and the low trace element contents in alluvial sequence from the Mefou River are linked to the intensity of the hydrodynamic forces. The rock sources have undergone high degree of weathering and there is no evidence of significant sediment recycling.
机译：来自雅温得地区（喀麦隆南部）梅富河右阶的九个沉积物岩心样本被用来调查沉积物的来源和演变。使用XRD，XRF和ICP-MS仪器已经报告了矿物和地球化学数据。沉积物芯为87厘米厚，从下到上细分为沙质，黏性沙质和粉质沙质层。沙层厚度为70厘米，从底部到顶部的晶粒尺寸逐渐减小。九个沉积物岩心样品主要由石英，副长石，高岭石，针铁矿，金红石和白云母/螨组成。这种矿物组合可以用变质烃源岩和周围土壤的综合作用来解释。 SiO2含量高，特别是在序列底部（71-85 wt％）证实了沙质质地以及石英的丰度。较高的SiO2 / Al2O3，较低的碱（Na2O + K2O）值，较低的REE含量（约107-389 ppm；平均= 247 ppm）以及SiO2与大多数主要和痕量元素之间的负相关性，证实了硅的硅弹特性。沉积物。 SiO2 / Al2O3的比例证明了石英相对于粘土矿物的高比例以及沉积物的粗粒度。 Mefou冲积沉积物分为铁页岩和铁砂。 LREE / HREE比和（La / Yb）（N）值显示出轻稀土元素的丰度，与稀土元素矿物的性质有关。蜘蛛图显示由于长石蚀变和石英丰度高，钾和锶的消耗量很大。相对于球粒陨石的REE归一化刻画出轻微的正Ce异常（Ce / Ce *类似于1.11-1.15）和负Eu异常（Eu / Eu *类似于0.43-0.63）。矿物学和地球化学特征与结构一致参数和描绘从片麻岩基底继承下来的沉积物的硅质碎屑性。梅富河冲积层中的砂土优势和微量元素含量低与流体动力的强度有关。岩石源遭受了高度的风化，没有证据表明大量的沉积物被回收。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号