Carbon flux and C, S isotopic characteristics of river waters from a karstic and a granitic terrain in the Yangtze River system

Chemical weathering and the role of sulfuric and nitric acids in carbonate weathering: Isotopes (13C, 15N, 34S, and 18O) and chemical constraints

“…The results suggest that the oxidation of sulfides contributes 73% to the Wujiang River. The contribution of evaporites is 20%, similar to the result of the sulfur isotopes of a tributary in Wujiang River [ Ji and Jiang , ]. The average contribution of atmospheric input is 8%, which is 7% lower than that estimated by the method using Cl − as a reference.…”

“…Figure c shows the correlation between δ 34 S and δ 13 C‐DIC in the Wujiang River. Increasing δ 13 C‐DIC values with decreasing δ 34 S values confirm the involvement of sulfuric acid in carbonate weathering, which is similar to the study by Spence and Telmer [] and Ji and Jiang [].…”

“…Consumption of CO 2 during rock weathering plays an important role in the biogeochemical cycle of carbon and therefore in global climate change [ Berner et al, ; Suchet and Probst , ; Gaillardet et al, ; Roy et al, ]. Numerous studies have indicated that carbonate and silicate weathering strongly influences riverine water chemistry, and even in silicate‐dominated terrain, carbonate weathering plays an important role in the chemical composition of rivers [ Gaillardet et al, ; Barth et al, ; Ji and Jiang , ]. On a geological timescale, silicate weathering regulates the greenhouse effect [ Walker et al, ].…”

“…Consequently, both silicate and carbonate weathering have potential climate implications [ Galy and France‐Lanord , ; Semhi et al, ; Spence and Telmer , ; Raymond et al, ]. Cycling rock from the continent to the oceans is a nonsteady state process, as evidenced by the uneven distribution of dolomite through geological time [ Mckenzie , ], but the extent to which this is coupled to the inorganic carbon cycle in a karstic terrain is uncertain [ Ji and Jiang , ]. Hence, studying rock weathering rates and associated CO 2 consumption in carbonate‐dominated areas is essential for understanding the carbon cycle both locally and globally.…”

Geochemistry of the dissolved loads during high-flow season of rivers in the southeastern coastal region of China: anthropogenic impact on chemical weathering and carbon sequestration

“…Compared with the major rivers in China, the average TDS was significantly lower than the Changjiang (224 mg L −1 , Chetelat et al, 2008), the Huanghe (557 mg L −1 , Fan et al, 2014) and the Zhujiang (190 mg L −1 , S. . However, the average TDS was comparable to the rivers draining silicaterock-dominated areas, e.g., the upper Ganjiang in Ganzhou, south China (63 mg L −1 , Ji and Jiang, 2012), the Amur in northern China (70 mg L −1 , Moon et al, 2009), the Xishui in Hubei, central China (101 mg L −1 , Wu et al, 2013) and North Han River in South Korea (75.5 mg L −1 , Ryu et al, 2008). Among the major rivers in the SECRB, the Qiantang had the highest TDS value (averaging at 121 mg L −1 ), and the Ou had the lowest TDS value (averaging at 48.8 mg L −1 ).…”