Abstract The Middle Miocene to Early Pleistocene Siwalik Group is composed of sediments deposited in the Himalayan foreland basin. In this study, the heavy mineral assemblage and chemical composition of detrital garnets from the sandstones in the Lower Siwalik sub-group, which are exposed along the Karnali River in western Nepal and the Tinau Khola in central Nepal, are studied and the provenance shift during the Middle Miocene is discussed. The heavy mineral assemblage in the lower section of the Lower Siwalik sub-group is characterized as predominantly zircon-tourmaline-rutile. Chemical analysis of the detrital garnets showed a monomodal almandine-rich composition with low pyrope (Prp

中文翻译：

---

来自尼泊尔西部和中部 Siwalik 前陆盆地沉积物的碎屑石榴石的化学成分揭示了高喜马拉雅结晶的中中新世剥蚀

摘要 中中新世至早更新世西瓦利克群由沉积于喜马拉雅前陆盆地的沉积物组成。在这项研究中，研究了出露在尼泊尔西部 Karnali 河和尼泊尔中部 Tinau Khola 沿线的下 Siwalik 亚群砂岩中碎屑石榴石的重矿物组合和化学成分，以及在此期间的物源转移。讨论了中中新世。下 Siwalik 亚群下部的重矿物组合的特征主要是锆石-电气石-金红石。碎屑柘榴石的化学分析表明，它是一种单峰富铝榴石成分，具有低镁铝榴石 (Prp