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Research paper thumbnail of Rock denudation rates and organic carbon exports along a latitudinal gradient in the Hudson, James, and Ungava bays watershed

Canadian Journal of Earth Sciences, Jun 1, 2012

This study documents chemical denudation rates (CDR) in the Canadian Shield and Interior Platform... more This study documents chemical denudation rates (CDR) in the Canadian Shield and Interior Platform. It focuses on the dissolved chemistry of rivers flowing into the Hudson, James, and Ungava bays (HJUB). Major ions, strontium, neodymium, and dissolved organic carbon (DOC) concentrations were monitored in four rivers (Koksoak, Great Whale, La Grande, and Nelson). Six other rivers flowing into the HJUB were sampled during baseflow and snowmelt conditions. The rivers of the Canadian Shield exhibit major cation concentrations ranging between 62 and 360 µmol/L, [Nd] of 0.57–4.72 nmol/L, and variable [DOC] of 241–1777 µmol/L. In comparison, the Nelson River (Interior Platform) shows higher major cation concentrations (1200–2276 µmol/L), lower [Nd] (0.14–0.45 nmol/L), and intermediate [DOC] (753–928 µmol/L). Altogether, the studied rivers export 8 × 106 t/year of dissolved major cations and 50 t/year of dissolved Nd towards the HJUB. Basin-scale rock denudation rates (RDR) range from 1.0 to 5.3 t·km–2·year–1 and are essentially controlled by lithology, as illustrated by the relationship established between RDR and the proportion of sedimentary and volcanic rocks (%S + %V) within the basins: RDR = 0.08(%S + %V) + 0.9. In contrast, dissolved Nd exports (and likely other insoluble elements) seem to be dependent upon organic matter leaching, as illustrated by the empirical coupling between Nd and DOC exports. These fluxes decrease northwards, likely in response to the hydroclimatic gradient. The CDR evaluated within the Canadian Shield are among the lowest on the planet, and the alkalinity generated by rock weathering remains small with respect to DOC exports.

Research paper thumbnail of diagenesis of lignin and bulk organic matter in of the Lower St. Lawrence Estuary and the Saguenay Fjord

Research paper thumbnail of The Differential Geochemical Behavior of Arsenic and Phosphorus in the Water Column and Sediments of the Saguenay Fjord Estuary, Canada

Aquatic Geochemistry, 2000

The distribution and partitioning of dissolved andparticulate arsenic and phosphorus in the water... more The distribution and partitioning of dissolved andparticulate arsenic and phosphorus in the water columnand sediments of the Saguenay Fjord in Quebec, Canada,are compared. In addition, selective and/or sequentialextractions were carried out on the suspendedparticulate matter (SPM) and solid sediments tocontrast their geochemical behaviors in this naturalaquatic system.Results of our analyses show that both arsenic andsoluble reactive phosphate are actively scavenged

Research paper thumbnail of Rock denudation rates and organic carbon exports along a latitudinal gradient in the Hudson, James, and Ungava bays watershed

Canadian Journal of Earth Sciences, 2012

This study documents chemical denudation rates (CDR) in the Canadian Shield and Interior Platform... more This study documents chemical denudation rates (CDR) in the Canadian Shield and Interior Platform. It focuses on the dissolved chemistry of rivers flowing into the Hudson, James, and Ungava bays (HJUB). Major ions, strontium, neodymium, and dissolved organic carbon (DOC) concentrations were monitored in four rivers (Koksoak, Great Whale, La Grande, and Nelson). Six other rivers flowing into the HJUB were sampled during baseflow and snowmelt conditions. The rivers of the Canadian Shield exhibit major cation concentrations ranging between 62 and 360 µmol/L, [Nd] of 0.57–4.72 nmol/L, and variable [DOC] of 241–1777 µmol/L. In comparison, the Nelson River (Interior Platform) shows higher major cation concentrations (1200–2276 µmol/L), lower [Nd] (0.14–0.45 nmol/L), and intermediate [DOC] (753–928 µmol/L). Altogether, the studied rivers export 8 × 106 t/year of dissolved major cations and 50 t/year of dissolved Nd towards the HJUB. Basin-scale rock denudation rates (RDR) range from 1.0 to...

Research paper thumbnail of Sources and early diagenesis of lignin and bulk organic matter in the sediments of the Lower St. Lawrence Estuary and the Saguenay Fjord

Marine Chemistry, 1997

... e1aina aie 8a 05), aien DN aaei oaaa ayeaEo eoAiao a1 2325 oeo 1535 no o1aaoa1 Ue1 1inaaaea(1... more ... e1aina aie 8a 05), aien DN aaei oaaa ayeaEo eoAiao a1 2325 oeo 1535 no o1aaoa1 Ue1 1inaaaea(1 niieieie 1o Uo a Aan1ia i ( OI Ua1i o 1Ua1 AaoE 1i aaanU a oa1ea iA 40 a1 oa UiEio iA (Ua niaay (OaU1a 2). A1io1n (D )(, Ai11i o oa yaoa oaeao ao DE aa1 , o11U n1i a 1i ...

Research paper thumbnail of Rock denudation rates and organic carbon exports along a latitudinal gradient in the Hudson, James, and Ungava bays watershed

Canadian Journal of Earth Sciences, Jun 1, 2012

This study documents chemical denudation rates (CDR) in the Canadian Shield and Interior Platform... more This study documents chemical denudation rates (CDR) in the Canadian Shield and Interior Platform. It focuses on the dissolved chemistry of rivers flowing into the Hudson, James, and Ungava bays (HJUB). Major ions, strontium, neodymium, and dissolved organic carbon (DOC) concentrations were monitored in four rivers (Koksoak, Great Whale, La Grande, and Nelson). Six other rivers flowing into the HJUB were sampled during baseflow and snowmelt conditions. The rivers of the Canadian Shield exhibit major cation concentrations ranging between 62 and 360 µmol/L, [Nd] of 0.57–4.72 nmol/L, and variable [DOC] of 241–1777 µmol/L. In comparison, the Nelson River (Interior Platform) shows higher major cation concentrations (1200–2276 µmol/L), lower [Nd] (0.14–0.45 nmol/L), and intermediate [DOC] (753–928 µmol/L). Altogether, the studied rivers export 8 × 106 t/year of dissolved major cations and 50 t/year of dissolved Nd towards the HJUB. Basin-scale rock denudation rates (RDR) range from 1.0 to 5.3 t·km–2·year–1 and are essentially controlled by lithology, as illustrated by the relationship established between RDR and the proportion of sedimentary and volcanic rocks (%S + %V) within the basins: RDR = 0.08(%S + %V) + 0.9. In contrast, dissolved Nd exports (and likely other insoluble elements) seem to be dependent upon organic matter leaching, as illustrated by the empirical coupling between Nd and DOC exports. These fluxes decrease northwards, likely in response to the hydroclimatic gradient. The CDR evaluated within the Canadian Shield are among the lowest on the planet, and the alkalinity generated by rock weathering remains small with respect to DOC exports.

Research paper thumbnail of diagenesis of lignin and bulk organic matter in of the Lower St. Lawrence Estuary and the Saguenay Fjord

Research paper thumbnail of The Differential Geochemical Behavior of Arsenic and Phosphorus in the Water Column and Sediments of the Saguenay Fjord Estuary, Canada

Aquatic Geochemistry, 2000

The distribution and partitioning of dissolved andparticulate arsenic and phosphorus in the water... more The distribution and partitioning of dissolved andparticulate arsenic and phosphorus in the water columnand sediments of the Saguenay Fjord in Quebec, Canada,are compared. In addition, selective and/or sequentialextractions were carried out on the suspendedparticulate matter (SPM) and solid sediments tocontrast their geochemical behaviors in this naturalaquatic system.Results of our analyses show that both arsenic andsoluble reactive phosphate are actively scavenged

Research paper thumbnail of Rock denudation rates and organic carbon exports along a latitudinal gradient in the Hudson, James, and Ungava bays watershed

Canadian Journal of Earth Sciences, 2012

This study documents chemical denudation rates (CDR) in the Canadian Shield and Interior Platform... more This study documents chemical denudation rates (CDR) in the Canadian Shield and Interior Platform. It focuses on the dissolved chemistry of rivers flowing into the Hudson, James, and Ungava bays (HJUB). Major ions, strontium, neodymium, and dissolved organic carbon (DOC) concentrations were monitored in four rivers (Koksoak, Great Whale, La Grande, and Nelson). Six other rivers flowing into the HJUB were sampled during baseflow and snowmelt conditions. The rivers of the Canadian Shield exhibit major cation concentrations ranging between 62 and 360 µmol/L, [Nd] of 0.57–4.72 nmol/L, and variable [DOC] of 241–1777 µmol/L. In comparison, the Nelson River (Interior Platform) shows higher major cation concentrations (1200–2276 µmol/L), lower [Nd] (0.14–0.45 nmol/L), and intermediate [DOC] (753–928 µmol/L). Altogether, the studied rivers export 8 × 106 t/year of dissolved major cations and 50 t/year of dissolved Nd towards the HJUB. Basin-scale rock denudation rates (RDR) range from 1.0 to...

Research paper thumbnail of Sources and early diagenesis of lignin and bulk organic matter in the sediments of the Lower St. Lawrence Estuary and the Saguenay Fjord

Marine Chemistry, 1997

... e1aina aie 8a 05), aien DN aaei oaaa ayeaEo eoAiao a1 2325 oeo 1535 no o1aaoa1 Ue1 1inaaaea(1... more ... e1aina aie 8a 05), aien DN aaei oaaa ayeaEo eoAiao a1 2325 oeo 1535 no o1aaoa1 Ue1 1inaaaea(1 niieieie 1o Uo a Aan1ia i ( OI Ua1i o 1Ua1 AaoE 1i aaanU a oa1ea iA 40 a1 oa UiEio iA (Ua niaay (OaU1a 2). A1io1n (D )(, Ai11i o oa yaoa oaeao ao DE aa1 , o11U n1i a 1i ...