Decoupling of dissolved and particulate Li isotopes during estuarine processes

Lithium isotopes in marine authigenic or detrital sedimentary archives have been recently used to trace continental weathering over geologic timescales. However, interpretations are predominantly based on the assumption that riverine Li isotopic signals can be propagated through estuaries without modification. Here, we verify this hypothesis by investigating behaviour of Changjiang (Yangtze) River estuary. We observe a conservative mixing dissolved and its between water seawater. The δ 7 yields non-linear increase with salinity, significant occurs during initial mixing. Through studied transect, estuarine flocculation resuspension processes cause homogenisation offshore particulate values, which close average composition upper crust. This study provides clear direct evidence signal is not modified large rivers, but caution should exercised when using marginal seas investigate past weathering.