Source to sink analysis of weathering fluxes in Lake Baikal and its watershed based on riverine fluxes, elemental lake budgets, REE patterns, and radiogenic (Nd, Sr) and 10Be/9Be isotopes ...

• Main Authors: Suhrhoff, Tim Jesper, Rickli, Jörg, Christl, Marcus, Vologina, Elena G., Pham, Viet, Belhadj, Moustafa, Sklyarov, Eugene V., Jeandel, Catherine, Vance, Derek
• Format: Text
• Language: English
• Published: ETH Zurich 2022
• Subjects: Lake Baikal; Weathering; Erosion; Denudation; Meteoric beryllium; Radiogenic isotopes; REE; permafrost
• Online Access: https://dx.doi.org/10.3929/ethz-b-000533345; http://hdl.handle.net/20.500.11850/533345

We present a detailed analysis of weathering fluxes at Lake Baikal, the largest lake in the world, using the major element, trace element and isotope geochemistry of major inflowing rivers, the lake itself, and its sediments. Our objective is to assess how lake records could be used to understand river-catchment-scale denudation and weathering processes. Total denudation rates at Lake Baikal, as obtained from meteoric 10Be/9Be, are an order of magnitude lower than the global average, at 16–35 t km−2 yr−1. Chemical weathering rates obtained from the riverine dissolved load and discharge are, on the other hand, in the same range as global values, at 6–29 t km−2 yr−1. Chemical weathering rates are higher in the north of the catchment than in the south, consistent with higher runoff in the north. In contrast, 10Be/9Be-derived denudation rates are higher in the south. We hypothesize that this pattern of variation may be due to the stabilizing effect of permafrost soils preventing erosion in the north. An inverse ... : Geochimica et Cosmochimica Acta, 321 ...