Provenance, source weathering, and tectonics of the Yarlung Zangbo River overbank sediments in Tibetan Plateau, China, using major, trace, and rare earth elements

Abstract

This paper studies the major, trace, and rare earth elements (REEs) in fluvial sediments from the Yarlung Zangbo River (YZR) on the Tibetan Plateau, China, with the aim of investigating their provenances, sediment maturity, weathering conditions, and tectonic settings. All samples and analytical techniques are based on Environmental Geochemical Monitoring Networks, which are a crucial part of IGCP259/360 (Global Geochemical Baseline). The results show that the YZR sediments consist of greywacke and litharenite with low-moderate maturities of textures and minerals. The chemical index of alteration (CIA) (49-71), plagioclase index of alteration (49-77), and index of compositional variability (ICV) values (0.82-1.54) indicate that both mature and immature sediments are present in the YZR and have experienced weak to moderate weathering with little intense weathering in the source area, which is also confirmed by the ICV-CIA, A-CN-K, A-CNK-FM, and MFW plots. Moreover, the provenance discrimination diagrams suggest that the YZR sediments are predominantly derived from felsic rocks that are close to the upper continental crust and from acid intermediates, and the tectonic settings of the YZR source rocks were associated with active continental margins and continental island arcs. The overall sediment types, weathering conditions, and tectonics of the YZR were consistent with those of the Brahmaputra River and Meghna River during the Himalayan-Tibetan orogeny, while the sediments of the Brahmaputra River are characterized by recycled-quartzose sources when compared with the other two Himalayan rivers due to the contributions of quartzolithic composition.

Geochemical characteristics of shoreline sediments from the Bay of Bengal, Bangladesh: Implications for provenance and source‐rock weathering

“…The Al 2 O 3 /TiO 2 and TiO 2 /Zr ratios in clastic sediments have been extensively used to interpret source‐rock variations in sedimentary basins (Hayashi et al, 1997; Hossain, 2020; Huyan et al, 2022). Hayashi et al (1997) reported that Al 2 O 3 /TiO 2 ratios in mafic, intermediate and felsic igneous rocks are 3–8, ~8–21 and ~21–70, respectively.…”

“…The Al 2 O 3 /TiO 2 and TiO 2 /Zr ratios in clastic sediments have been extensively used to interpret source-rock variations in sedimentary basins (Hayashi et al, 1997;Hossain, 2020;Huyan et al, 2022). Hayashi et al (1997) (Hayashi et al, 1997).…”

“…The Brahmaputra River drains the northeastern part of the Himalayas and flows over metamorphic rocks (high‐grade schist, gneiss, quartzite and carbonate), felsic igneous rocks and sedimentary rocks (sandstone, shale and limestone; Heroy, Kuehl, & Goodbred, 2003; Yoshimura et al, 2021). The Yarlung Zangbo River originates in the northern part of the Himalayas, joins the upper reaches of the Brahmaputra River, and flows over metasedimentary, metamorphic, and volcanic rocks in the Tibetan Plateau (Huyan, Yao, Xie, & Wang, 2022). The Meghna River flows over the complex geology (pelagic and flysch sediment, shale and limestone) of the eastern Himalayas and Indo‐Burman Ranges (Allen et al, 2008; Hossain, 2020).…”

“…The petrographic composition of sands is commonly used for the identification of provenance in sedimentary basins (Dickinson et al, 1983; Hossain et al, 2010; Ingersoll & Suczek, 1979; Ramos‐Vázquez & Armstrong‐Altrin, 2021). The chemical composition of clastic sediments is extensively applied to infer the chemical weathering of parental rocks, source compositions, recycling and provenance (Anaya‐Gregorio, Armstrong‐Altrin, Machain‐Castillo, Montiel‐García, & Ramos‐Vázquez, 2018; Armstrong‐Altrin et al, 2015; Cox, Lowe, & Cullers, 1995; Fedo, Eriksson, & Krogstad, 1996; Fedo, Nesbitt, & Young, 1995; Garver, Royce, & Smick, 1996; Garzanti et al, 2010; Garzanti, Wang, Vezzoli, & Limonta, 2016; Hayashi, Fujisawa, Holland, & Ohmoto, 1997; Hossain, 2020; Hossain et al, 2018; Huyan et al, 2022; Liu et al, 2017; McLennan, Hemming, McDaniel, & Hanson, 1993; Nesbitt & Young, 1982; Taylor & McLennan, 1985). Detrital sediments are primarily influenced by diagenetic processes and recycling during fluvial transportation and deposition, but their mineralogical and geochemical composition is largely dependent on the source rock (Armstrong‐Altrin, Lee, Kasper‐Zubillaga, & Trejo‐Ramírez, 2017; Hossain et al, 2018; Liu et al, 2012; Ramos‐Vázquez & Armstrong‐Altrin, 2021).…”

Application of a new distributed hydrological model based on soil–gravel structure in the Niyang River Basin, Qinghai–Tibet Plateau

“…It originates from Cuomoliang Mountain on the west side of the Mila Mountain in the Tibet Autonomous Region of China at an altitude of approximately 5,000 m above sea level (a.s.l.). The basin sediments consist of greywacke and litharenitewith low-moderate maturities of textures and minerals (Huyan et al, 2022). The terrain in the watershed is complex, with staggered large and small mountains and large elevation fluctuations.…”