...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Current Science: A Fortnightly Journal of Research >The geochemistry of Mesoproterozoic clastic sedimentary rocks from the Rautgara Formation, Kumaun Lesser Himalaya: implications for provenance, mineralogical control and weathering.
【24h】

The geochemistry of Mesoproterozoic clastic sedimentary rocks from the Rautgara Formation, Kumaun Lesser Himalaya: implications for provenance, mineralogical control and weathering.

机译：来自库玛恩小喜马拉雅山Rautgara组的中元古代碎屑沉积岩的地球化学：对物源，矿物学控制和风化的影响。

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 Mesoproterozoic clastic sedimentary rocks, comprising pelites and quartzites from the Rautgara Formation, Kumaun Lesser Himalaya (India), have been analysed for major and trace elements, including Rare Earth Elements (REEs) to evaluate their provenance and weathering history. The pelitic rocks are characterized by moderate SiO2 and Al2O3 contents and show consistent REE patterns with LREE (light REE)-enriched and HREE (heavy REE)-depleted patterns (LaNYbN=7.4-10.3). The total REE abundances of Rautgara pelites are high (up to 266 ppm) with large negative Eu-anomalies (Eu/Eu*=0.57-0.64). Except high SiO2 contents, the other major and trace element concentrations are significantly low in the associated quartzites. Although the quartzites contain low REE abundances (up to 41 ppm), their patterns, including negative Eu anomalies, are akin to pelites, suggesting that both the rock types be derived from similar source. The Chemical Index of Alteration and A-CN-K parameters indicate that moderate chemical weathering has taken place in the source region of the Rautgara rocks. The linear correlation coefficients between Al2O3, K2O, TiO2 and total REE reveal that the accessory minerals (mainly Ti-bearing phases) have hosted the REEs. The striking similarities between the REE patterns of Rautgara pelites and BGC of Aravalli and Bundelkhand granitoids, which are consistent with the palaeocurrent studies of the area, indicate that the granitoid rocks from these regions have supplied detritus to the Lesser Himalayan Rautgara sedimentary basin..
机译：分析了中古生代碎屑沉积岩，其中包括来自印度库玛恩·小喜马拉雅山拉特加拉组的菱铁矿和石英岩，分析了其中的主要和微量元素，包括稀土元素（REEs），以评估其来源和风化历史。黄土岩的特征是中等的SiO2和Al2O3含量，并显示出一致的REE模式，以及富含LREE（轻REE）和HREE（重REE）的模式（LaNYbN = 7.4-10.3）。 Rautgara pelite的总REE丰度很高（高达266 ppm），且Eu异常较大（Eu / Eu * = 0.57-0.64）。除了较高的SiO2含量外，伴生的石英岩中其他主要元素和痕量元素的浓度也很低。尽管石英岩的稀土元素丰度较低（最高41 ppm），但它们的模式（包括负Eu异常）类似于贝利特岩，表明这两种岩石类型均来自相似的来源。化学蚀变指数和A-CN-K参数表明在Rautgara岩石的源区发生了中等程度的化学风化。 Al2O3，K2O，TiO2和总REE之间的线性相关系数表明，辅助矿物（主要是含Ti的相）已经包含了REE。 Rautgara泥岩的REE模式与Aravalli和Bundelkhand花岗岩的BGC之间的惊人相似性，与该地区的古流研究相一致，表明这些地区的花岗岩岩石已向小喜马拉雅Rautgara沉积盆地提供了碎屑。

著录项

相似文献

  • 外文文献
  • 中文文献
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