Comment on “Holocene evolution in weathering and erosion patterns in the Pearl River delta” by Hu et al.

Abstract

A recent paper [Hu et al., 2013] reports Holocene evolution in weathering and erosion patterns in the Pearl River delta. The paper concludes the modern Pearl River is a poor proxy for understanding the typical erosional flux from southern China to the South China Sea (SCS), principally based on low smectite percentage in the modern river sediments but high smectite percentage in two cores through much of the Holocene, which may lead to misinterpretation of depositional environment in the deep-sea basin from the SCS. In this comment, we first point out that core locations determine sedimentary records in the Pearl River delta. Second, we show that high smectite percentage at both cores during the Holocene was correlated with weathering of neighboring islands or even transported by coastal currents from nearby bays, instead of sediment supply changes from South China via the Pearl River. We thus conclude that sediment flux of the Pearl River remained relatively stable during the Holocene and correlated parameters derived from the river sediments could be utilized to effectively trace sediment sources in deepwater environments from the northern SCS.