A spectroscopy and isotope study of sediments from the Antarctic Dry Valleys as analogues for potential paleolakes on Mars
A spectroscopy and isotope study has been performed on igneous sediments from Lake Hoare, a nearly isolated ecosystem in the Dry Valleys region of Antarctica. The mineralogy and chemistry of these sediments were studied in order to gain insights into the biogeochemical processes occurring in a perma...
Published in: | International Journal of Astrobiology |
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crcambridgeupr:10.1017/s1473550403001654 2024-09-15T17:43:21+00:00 A spectroscopy and isotope study of sediments from the Antarctic Dry Valleys as analogues for potential paleolakes on Mars Bishop, Janice L. Anglen, Brandy L. Pratt, Lisa M. Edwards, Howell G. M. Des Marais, David J. Doran, Peter T. 2003 http://dx.doi.org/10.1017/s1473550403001654 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1473550403001654 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms International Journal of Astrobiology volume 2, issue 4, page 273-287 ISSN 1473-5504 1475-3006 journal-article 2003 crcambridgeupr https://doi.org/10.1017/s1473550403001654 2024-07-17T04:02:17Z A spectroscopy and isotope study has been performed on igneous sediments from Lake Hoare, a nearly isolated ecosystem in the Dry Valleys region of Antarctica. The mineralogy and chemistry of these sediments were studied in order to gain insights into the biogeochemical processes occurring in a permanently ice-covered lake and to assist in characterizing potential habitats for life in paleolakes on Mars. Obtaining visible/near-infrared, mid-infrared and Raman spectra of such sediments provides the ground truth needed for using reflectance, emittance and Raman spectroscopy for exploration of geology, and perhaps biology, on Mars. Samples measured in this study include a sediment from the ice surface, lake bottom sediment cores from oxic and anoxic zones of the lake and the magnetic fractions of two samples. These sediments are dominated by quartz, pyroxene, plagioclase and K-feldspar, but also contain calcite, organics, clays, sulphides and iron oxides/hydroxides that resulted from chemical and biological alteration processes. Chlorophyll-like bands are observed in the spectra of the sediment-mat layers on the surface of the lake bottom, especially in the deep anoxic region. Layers of high calcite concentration in the oxic sediments and layers of high pyrite concentration in the anoxic sediments are indicators of periods of active biogeochemical processing in the lake. Micro-Raman spectra revealed the presence of ~5 μm-sized pyrite deposits on the surface of quartz grains in the anoxic sediments. C, N and S isotope trends are compared with the chemistry and spectral properties. The δ 13 C and δ 15 N trends highlight the differences in the balance of microbial processes in the anoxic sediments versus the oxic sediments. The biogenic pyrite found in the sediments from the anoxic zone is associated with depleted δ 34 S values, high organic C levels and chlorophyll spectral bands and could be used as a potential biomarker mineral for paleolakes on Mars. Article in Journal/Newspaper Antarc* Antarctic Antarctica Cambridge University Press International Journal of Astrobiology 2 4 273 287 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
A spectroscopy and isotope study has been performed on igneous sediments from Lake Hoare, a nearly isolated ecosystem in the Dry Valleys region of Antarctica. The mineralogy and chemistry of these sediments were studied in order to gain insights into the biogeochemical processes occurring in a permanently ice-covered lake and to assist in characterizing potential habitats for life in paleolakes on Mars. Obtaining visible/near-infrared, mid-infrared and Raman spectra of such sediments provides the ground truth needed for using reflectance, emittance and Raman spectroscopy for exploration of geology, and perhaps biology, on Mars. Samples measured in this study include a sediment from the ice surface, lake bottom sediment cores from oxic and anoxic zones of the lake and the magnetic fractions of two samples. These sediments are dominated by quartz, pyroxene, plagioclase and K-feldspar, but also contain calcite, organics, clays, sulphides and iron oxides/hydroxides that resulted from chemical and biological alteration processes. Chlorophyll-like bands are observed in the spectra of the sediment-mat layers on the surface of the lake bottom, especially in the deep anoxic region. Layers of high calcite concentration in the oxic sediments and layers of high pyrite concentration in the anoxic sediments are indicators of periods of active biogeochemical processing in the lake. Micro-Raman spectra revealed the presence of ~5 μm-sized pyrite deposits on the surface of quartz grains in the anoxic sediments. C, N and S isotope trends are compared with the chemistry and spectral properties. The δ 13 C and δ 15 N trends highlight the differences in the balance of microbial processes in the anoxic sediments versus the oxic sediments. The biogenic pyrite found in the sediments from the anoxic zone is associated with depleted δ 34 S values, high organic C levels and chlorophyll spectral bands and could be used as a potential biomarker mineral for paleolakes on Mars. |
format |
Article in Journal/Newspaper |
author |
Bishop, Janice L. Anglen, Brandy L. Pratt, Lisa M. Edwards, Howell G. M. Des Marais, David J. Doran, Peter T. |
spellingShingle |
Bishop, Janice L. Anglen, Brandy L. Pratt, Lisa M. Edwards, Howell G. M. Des Marais, David J. Doran, Peter T. A spectroscopy and isotope study of sediments from the Antarctic Dry Valleys as analogues for potential paleolakes on Mars |
author_facet |
Bishop, Janice L. Anglen, Brandy L. Pratt, Lisa M. Edwards, Howell G. M. Des Marais, David J. Doran, Peter T. |
author_sort |
Bishop, Janice L. |
title |
A spectroscopy and isotope study of sediments from the Antarctic Dry Valleys as analogues for potential paleolakes on Mars |
title_short |
A spectroscopy and isotope study of sediments from the Antarctic Dry Valleys as analogues for potential paleolakes on Mars |
title_full |
A spectroscopy and isotope study of sediments from the Antarctic Dry Valleys as analogues for potential paleolakes on Mars |
title_fullStr |
A spectroscopy and isotope study of sediments from the Antarctic Dry Valleys as analogues for potential paleolakes on Mars |
title_full_unstemmed |
A spectroscopy and isotope study of sediments from the Antarctic Dry Valleys as analogues for potential paleolakes on Mars |
title_sort |
spectroscopy and isotope study of sediments from the antarctic dry valleys as analogues for potential paleolakes on mars |
publisher |
Cambridge University Press (CUP) |
publishDate |
2003 |
url |
http://dx.doi.org/10.1017/s1473550403001654 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1473550403001654 |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
International Journal of Astrobiology volume 2, issue 4, page 273-287 ISSN 1473-5504 1475-3006 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s1473550403001654 |
container_title |
International Journal of Astrobiology |
container_volume |
2 |
container_issue |
4 |
container_start_page |
273 |
op_container_end_page |
287 |
_version_ |
1810490291013025792 |