The global control of silicate weathering rates and the coupling with physical erosion: new insights from rivers of the Canadian Shield
International audience The chemical evolution of the surface of the Earth is controlled by the interaction of rainwaters, the atmosphere and the continental crust. That is the main reason why the knowledge of the parameters that control chemical denudation on Earth is of crucial importance. We repor...
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ftunivnantes:oai:HAL:insu-03642964v1 2023-05-15T17:46:47+02:00 The global control of silicate weathering rates and the coupling with physical erosion: new insights from rivers of the Canadian Shield 2002 https://hal-insu.archives-ouvertes.fr/insu-03642964 https://doi.org/10.1016/S0012-821X(01)00599-4 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.1016/S0012-821X(01)00599-4 insu-03642964 https://hal-insu.archives-ouvertes.fr/insu-03642964 BIBCODE: 2002E&PSL.196.83M doi:10.1016/S0012-821X(01)00599-4 EARTH AND PLANETARY SCIENCE LETTERS https://hal-insu.archives-ouvertes.fr/insu-03642964 EARTH AND PLANETARY SCIENCE LETTERS, 2002, 196, pp.83-98. ⟨10.1016/S0012-821X(01)00599-4⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2002 ftunivnantes https://doi.org/10.1016/S0012-821X(01)00599-4 2022-06-29T00:28:53Z International audience The chemical evolution of the surface of the Earth is controlled by the interaction of rainwaters, the atmosphere and the continental crust. That is the main reason why the knowledge of the parameters that control chemical denudation on Earth is of crucial importance. We report chemical and isotopic analyses for river waters from the Canadian Shield in order to estimate chemical weathering fluxes. We present a comparison of the chemical composition and Sr isotopic composition of a set of rivers sampled in the Slave Province (Northwest Territories, Canada) and in the Grenville Province (Québec, Canada). The surface waters of these high latitude catchments are very dilute, with the Slave rivers about three times more concentrated than the Grenville rivers. A detailed analysis of the Sr isotopic composition and chemical signature of these rivers shows that silicate weathering reactions are not the only mechanisms that control solute concentrations. An atmospheric component, constituted by the dissolution of evaporite and carbonate aerosols, is necessary to explain the dispersion of chemical ratios such as Ca/Na, Mg/Na, Sr/Na and Cl/Na. These aerosols probably have a local origin. Chemical denudation rates for the Slave Province are four times lower than those found in the Grenville Province (0.35 and 1.55 tons/km 2 /yr respectively). Compared to a panel of surface waters from other shield areas of the world, the Slave Province appears to have the lowest chemical denudation rate in the world. In a chemical weathering rate vs. temperature plot, shield rivers define a triangular relationship, hot climate being able to produce the most variable denudation rates. But no simple relationship between chemical weathering rates and temperature or runoff is observed, in contrast to rivers draining basaltic areas. We show that a global power law (0.66 exponent) exists between chemical denudation rates and physical denudation rates, indicating that the shield areas with low mechanical denudation (such ... Article in Journal/Newspaper Northwest Territories Université de Nantes: HAL-UNIV-NANTES Canada Northwest Territories Earth and Planetary Science Letters 196 1-2 83 98 |
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Université de Nantes: HAL-UNIV-NANTES |
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ftunivnantes |
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English |
topic |
[SDU]Sciences of the Universe [physics] |
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[SDU]Sciences of the Universe [physics] The global control of silicate weathering rates and the coupling with physical erosion: new insights from rivers of the Canadian Shield |
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[SDU]Sciences of the Universe [physics] |
description |
International audience The chemical evolution of the surface of the Earth is controlled by the interaction of rainwaters, the atmosphere and the continental crust. That is the main reason why the knowledge of the parameters that control chemical denudation on Earth is of crucial importance. We report chemical and isotopic analyses for river waters from the Canadian Shield in order to estimate chemical weathering fluxes. We present a comparison of the chemical composition and Sr isotopic composition of a set of rivers sampled in the Slave Province (Northwest Territories, Canada) and in the Grenville Province (Québec, Canada). The surface waters of these high latitude catchments are very dilute, with the Slave rivers about three times more concentrated than the Grenville rivers. A detailed analysis of the Sr isotopic composition and chemical signature of these rivers shows that silicate weathering reactions are not the only mechanisms that control solute concentrations. An atmospheric component, constituted by the dissolution of evaporite and carbonate aerosols, is necessary to explain the dispersion of chemical ratios such as Ca/Na, Mg/Na, Sr/Na and Cl/Na. These aerosols probably have a local origin. Chemical denudation rates for the Slave Province are four times lower than those found in the Grenville Province (0.35 and 1.55 tons/km 2 /yr respectively). Compared to a panel of surface waters from other shield areas of the world, the Slave Province appears to have the lowest chemical denudation rate in the world. In a chemical weathering rate vs. temperature plot, shield rivers define a triangular relationship, hot climate being able to produce the most variable denudation rates. But no simple relationship between chemical weathering rates and temperature or runoff is observed, in contrast to rivers draining basaltic areas. We show that a global power law (0.66 exponent) exists between chemical denudation rates and physical denudation rates, indicating that the shield areas with low mechanical denudation (such ... |
format |
Article in Journal/Newspaper |
title |
The global control of silicate weathering rates and the coupling with physical erosion: new insights from rivers of the Canadian Shield |
title_short |
The global control of silicate weathering rates and the coupling with physical erosion: new insights from rivers of the Canadian Shield |
title_full |
The global control of silicate weathering rates and the coupling with physical erosion: new insights from rivers of the Canadian Shield |
title_fullStr |
The global control of silicate weathering rates and the coupling with physical erosion: new insights from rivers of the Canadian Shield |
title_full_unstemmed |
The global control of silicate weathering rates and the coupling with physical erosion: new insights from rivers of the Canadian Shield |
title_sort |
global control of silicate weathering rates and the coupling with physical erosion: new insights from rivers of the canadian shield |
publisher |
HAL CCSD |
publishDate |
2002 |
url |
https://hal-insu.archives-ouvertes.fr/insu-03642964 https://doi.org/10.1016/S0012-821X(01)00599-4 |
geographic |
Canada Northwest Territories |
geographic_facet |
Canada Northwest Territories |
genre |
Northwest Territories |
genre_facet |
Northwest Territories |
op_source |
EARTH AND PLANETARY SCIENCE LETTERS https://hal-insu.archives-ouvertes.fr/insu-03642964 EARTH AND PLANETARY SCIENCE LETTERS, 2002, 196, pp.83-98. ⟨10.1016/S0012-821X(01)00599-4⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/S0012-821X(01)00599-4 insu-03642964 https://hal-insu.archives-ouvertes.fr/insu-03642964 BIBCODE: 2002E&PSL.196.83M doi:10.1016/S0012-821X(01)00599-4 |
op_doi |
https://doi.org/10.1016/S0012-821X(01)00599-4 |
container_title |
Earth and Planetary Science Letters |
container_volume |
196 |
container_issue |
1-2 |
container_start_page |
83 |
op_container_end_page |
98 |
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1766150621682991104 |