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Please use this identifier to cite or link to this item: http://repository.iitr.ac.in/handle/123456789/6115
Title: Geochemistry, dissolved elemental flux rates, and dissolution kinetics of lithologies of Alaknanda and Bhagirathi rivers in Himalayas, India
Authors: Yadav S.K.
Chakrapani, Govind Joseph
Published in: Environmental Earth Sciences
Abstract: Alaknanda and Bhagirathi (AB) river basins in the Himalayan region in India expose lithologies comprising mainly of granites, low-high-grade metamorphics, shales and carbonates which, in conjunction with the monsoon rains and glacial melt, control water chemistry and dissolved elemental flux rates. In the present study, we monitored two locations: (a) Srinagar on the Alaknanda river and (b) Maneri on the Bhagirathi river for daily variations in total suspended sediments, major ions and dissolved silica over one complete year (July 2004-June 2005). Based on long-term discharge data, discharge-weighted composition and dissolved elemental flux rates (with respect to Ca, Mg, HCO3, Si) of the river were estimated. The information thus obtained has substantially added up to the existing chemical data of these rivers and has refined the flux rates. Our high-frequency samples provide informations such as (a) water chemical compositions that show a large temporal and spatial variation and (b) carbonate lithology that controls water chemistry predominantly. The dissolution kinetics of various lithologies namely leucogranite, gneiss, quartzite, phyllite and shale of the AB river basins were studied through batch experiments at controlled temperature (25 and 5°C) and pH (8.4) condition. In laboratory, these lithologies undergo slow rates of dissolution (10-13 to 10-15 mol/m2 s), while field weathering rates based on dissolved elemental flux rates in the AB rivers are much higher (10-8 to 10-9 mol/m2 s). Extremely high physical weathering rates in AB rivers, which enhance chemical weathering significantly, mainly attribute this wide discrepancy in laboratory-derived rates of representative basin rocks and dissolved elemental fluxes in the field. However, laboratory-simulated experiments facilitate to quantify elemental release rates, understand the kinetics of the dissolution reactions, and compare their roles at individual level. © 2010 Springer-Verlag.
Citation: Environmental Earth Sciences (2011), 62(3): 593-610
URI: https://doi.org/10.1007/s12665-010-0550-2
http://repository.iitr.ac.in/handle/123456789/6115
Issue Date: 2011
Keywords: Batch experiments
Dissolution rate
Himalayan rivers
Kinetics
ISSN: 18666280
Author Scopus IDs: 35551299800
6701873646
Author Affiliations: Yadav, S.K., Department of Earth Sciences, Indian Institute of Technology, Roorkee 247667 Uttarakhand, India
Chakrapani, G.J., Department of Earth Sciences, Indian Institute of Technology, Roorkee 247667 Uttarakhand, India
Funding Details: Acknowledgments Funding for the study from the Department of Science and Technology (SR/S4-18/2002), Government of India is gratefully acknowledged.
Corresponding Author: Chakrapani, G. J.; Department of Earth Sciences, Indian Institute of Technology, Roorkee 247667 Uttarakhand, India; email: gjcurfes@iitr.ernet.in
Appears in Collections:Journal Publications [ES]

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