• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>South African Journal of Geology: Being the Transaction of the Geological Society of South African: Syndie die Verhandelinge van die Geologiese Vereniging van Suid-Afrika >Source of the suspended load of the upper Orange River, South Africa
【24h】

Source of the suspended load of the upper Orange River, South Africa

机译：南非奥兰治河上游悬浮物的来源

获取原文
获取原文并翻译 | 示例
       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Orange River is one of the World's most turbid; delivering 60 million tons of sediment each year to the western margin of South Africa. Much of this sediment is believed to be from soil erosion, an increasing environmental threat to sustainability in southern Africa. This study focuses on the upper reaches of the Orange River above the Caledon River confluence, because it is here that high rainfall and topographic relief of the Drakensberg Mountains produce most of the Orange River's suspended load. Comparison of grain size, mineralogy and geochemistry of the suspended sediment load with catchment bedrock soils provides,in estimate of the source of the suspended sediment. Major and trace element ratios indicate that the suspended sediment load is primarily derived from Karoo (upper Beaufort and Stormberg groups) sedimentary rocks rather than Drakensberg basalt. The Caledon River carries the largest fine-mud suspended load primarily from the erosion of Karoo sedimentary rock soils. The organic carbon content of the suspended load ranges from 1.0 to 1.3 weight % with delta C-13 values that range from -19.7 to 16.9 degrees/(00) PDB. The delta C-13 values of the organic fraction of soils is highly variable (-21.5 to -12.7 degrees/(00) PDB) and reflect the mix of C3 and C4 vegetation in the catchment area.
机译：奥兰治河是世界上最浑浊的河流之一。每年向南非西部边缘输送6000万吨的沉积物。据信，这些沉积物大部分来自土壤侵蚀，这对南部非洲的可持续性构成了越来越大的环境威胁。这项研究集中在卡利登河汇合处的奥兰治河上游，因为正是在这里，高降雨和德拉肯斯堡山脉的地形起伏产生了奥兰治河的大部分悬挂负荷。通过对流沙基岩土壤的悬浮物负荷的粒度，矿物学和地球化学的比较，可以估算悬浮物的来源。主要元素和微量元素之比表明，悬浮泥沙负荷主要来自Karoo（Beaufort和Stormberg上部群）沉积岩，而不是Drakensberg玄武岩。卡利登河的最大悬浮泥沙负荷主要来自卡鲁沉积岩土壤的侵蚀。悬浮物的有机碳含量范围为1.0到1.3重量％，δC-13值范围为-19.7到16.9度/（00）PDB。土壤有机质分数的C-13值变化很大（-21.5至-12.7度/（00）PDB），反映了集水区C3和C4植被的混合。

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