Chemical weathering in a terminal moraine at the ice sheet margin at Kangerlussuaq, western Greenland
Weathering caused by interaction between glacial sediments and water in exposed moraines needs to be studied to evaluate their possible effects on the global carbon cycle. In this study, moraine ponds, moraine porewaters, and till samples were collected at a moraine adjacent to the Greenland Ice She...
Published in: | Arctic, Antarctic, and Alpine Research |
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Language: | English |
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Online Access: | http://zaguan.unizar.es/record/88513 https://doi.org/10.1080/15230430.2019.1660125 |
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ftunivzaraaneto:oai:zaguan.unizar.es:88513 2023-05-15T15:52:48+02:00 Chemical weathering in a terminal moraine at the ice sheet margin at Kangerlussuaq, western Greenland Auqué, L.F. Puigdomenech, I. Tullborg, E-L. Gimeno, M.J. Grodzinsky, K. Hogmalm, K.J. 2019 application/pdf http://zaguan.unizar.es/record/88513 https://doi.org/10.1080/15230430.2019.1660125 eng eng http://zaguan.unizar.es/record/88513 doi:10.1080/15230430.2019.1660125 by http://creativecommons.org/licenses/by/3.0/es/ CC-BY info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2019 ftunivzaraaneto https://doi.org/10.1080/15230430.2019.1660125 2023-01-18T00:23:52Z Weathering caused by interaction between glacial sediments and water in exposed moraines needs to be studied to evaluate their possible effects on the global carbon cycle. In this study, moraine ponds, moraine porewaters, and till samples were collected at a moraine adjacent to the Greenland Ice Sheet at Kangerlussuaq. Scanning electron microscopy (SEM) studies of the till show limited evidence of silicate chemical weathering, but the moraine waters have substantial solute concentrations. d34SSO4 and d18OSO4 data indicate that the origin of dissolved sulfate is the oxidation of sulfides, in agreement with the SEM observations. The dissolved HCO3-/SO42- molar ratios indicate an uneven balance between sulfuric and carbonic acid weathering; C-isotope data indicate that some of the CO2 originates from organic carbon mineralization. Ion–ion plots provide evidence of carbonate weathering and of the formation of secondary gypsum and calcite through evaporation and (or) cryoconcentration. The 87Sr/86Sr ratios in the waters correlate with the corresponding till samples, supporting the local origin of the dissolved strontium, which is higher in the waters than in the till due to the selective weathering of biotite. The data evidence a large degree of chemical weathering in moraines promoted by large rock–water ratios and by the hydraulic isolation created by the frozen till. The high PCO2 in the studied moraine waters indicates that they may represent a previously underestimated CO2 source. Article in Journal/Newspaper Carbonic acid Greenland Ice Sheet Kangerlussuaq Digital Repository of University of Zaragoza (ZAGUAN) Greenland Kangerlussuaq ENVELOPE(-55.633,-55.633,72.633,72.633) Arctic, Antarctic, and Alpine Research 51 1 440 459 |
institution |
Open Polar |
collection |
Digital Repository of University of Zaragoza (ZAGUAN) |
op_collection_id |
ftunivzaraaneto |
language |
English |
description |
Weathering caused by interaction between glacial sediments and water in exposed moraines needs to be studied to evaluate their possible effects on the global carbon cycle. In this study, moraine ponds, moraine porewaters, and till samples were collected at a moraine adjacent to the Greenland Ice Sheet at Kangerlussuaq. Scanning electron microscopy (SEM) studies of the till show limited evidence of silicate chemical weathering, but the moraine waters have substantial solute concentrations. d34SSO4 and d18OSO4 data indicate that the origin of dissolved sulfate is the oxidation of sulfides, in agreement with the SEM observations. The dissolved HCO3-/SO42- molar ratios indicate an uneven balance between sulfuric and carbonic acid weathering; C-isotope data indicate that some of the CO2 originates from organic carbon mineralization. Ion–ion plots provide evidence of carbonate weathering and of the formation of secondary gypsum and calcite through evaporation and (or) cryoconcentration. The 87Sr/86Sr ratios in the waters correlate with the corresponding till samples, supporting the local origin of the dissolved strontium, which is higher in the waters than in the till due to the selective weathering of biotite. The data evidence a large degree of chemical weathering in moraines promoted by large rock–water ratios and by the hydraulic isolation created by the frozen till. The high PCO2 in the studied moraine waters indicates that they may represent a previously underestimated CO2 source. |
format |
Article in Journal/Newspaper |
author |
Auqué, L.F. Puigdomenech, I. Tullborg, E-L. Gimeno, M.J. Grodzinsky, K. Hogmalm, K.J. |
spellingShingle |
Auqué, L.F. Puigdomenech, I. Tullborg, E-L. Gimeno, M.J. Grodzinsky, K. Hogmalm, K.J. Chemical weathering in a terminal moraine at the ice sheet margin at Kangerlussuaq, western Greenland |
author_facet |
Auqué, L.F. Puigdomenech, I. Tullborg, E-L. Gimeno, M.J. Grodzinsky, K. Hogmalm, K.J. |
author_sort |
Auqué, L.F. |
title |
Chemical weathering in a terminal moraine at the ice sheet margin at Kangerlussuaq, western Greenland |
title_short |
Chemical weathering in a terminal moraine at the ice sheet margin at Kangerlussuaq, western Greenland |
title_full |
Chemical weathering in a terminal moraine at the ice sheet margin at Kangerlussuaq, western Greenland |
title_fullStr |
Chemical weathering in a terminal moraine at the ice sheet margin at Kangerlussuaq, western Greenland |
title_full_unstemmed |
Chemical weathering in a terminal moraine at the ice sheet margin at Kangerlussuaq, western Greenland |
title_sort |
chemical weathering in a terminal moraine at the ice sheet margin at kangerlussuaq, western greenland |
publishDate |
2019 |
url |
http://zaguan.unizar.es/record/88513 https://doi.org/10.1080/15230430.2019.1660125 |
long_lat |
ENVELOPE(-55.633,-55.633,72.633,72.633) |
geographic |
Greenland Kangerlussuaq |
geographic_facet |
Greenland Kangerlussuaq |
genre |
Carbonic acid Greenland Ice Sheet Kangerlussuaq |
genre_facet |
Carbonic acid Greenland Ice Sheet Kangerlussuaq |
op_relation |
http://zaguan.unizar.es/record/88513 doi:10.1080/15230430.2019.1660125 |
op_rights |
by http://creativecommons.org/licenses/by/3.0/es/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1080/15230430.2019.1660125 |
container_title |
Arctic, Antarctic, and Alpine Research |
container_volume |
51 |
container_issue |
1 |
container_start_page |
440 |
op_container_end_page |
459 |
_version_ |
1766387904383287296 |