Mineralogical and geochemical analyses of Antarctic lake sediments: A study of reflectance and Mössbauer spectroscopy and C, N, and S isotopes with applications for remote sensing on Mars
We analyzed lake-bottom sediments from the Dry Valleys region of Antarctica to study the influence of water chemistry on the mineralogy and geochemistry of these sediments, as well as to evaluate techniques for remote spectral identification of potential biomarker minerals on Mars. Lakes from the Dr...
Published in: | Geochimica et Cosmochimica Acta |
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Online Access: | https://digitalcommons.lsu.edu/geo_pubs/676 https://doi.org/10.1016/S0016-7037(01)00651-2 |
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ftlouisianastuir:oai:digitalcommons.lsu.edu:geo_pubs-1675 2023-06-11T04:07:15+02:00 Mineralogical and geochemical analyses of Antarctic lake sediments: A study of reflectance and Mössbauer spectroscopy and C, N, and S isotopes with applications for remote sensing on Mars Bishop, Janice L. Lougear, André Newton, Jason Doran, Peter T. Froeschl, Heinz Trautwein, Alfred X. Körner, Wilfried Koeberl, Christian 2001-01-01T08:00:00Z https://digitalcommons.lsu.edu/geo_pubs/676 https://doi.org/10.1016/S0016-7037(01)00651-2 unknown LSU Digital Commons https://digitalcommons.lsu.edu/geo_pubs/676 doi:10.1016/S0016-7037(01)00651-2 Faculty Publications text 2001 ftlouisianastuir https://doi.org/10.1016/S0016-7037(01)00651-2 2023-05-28T18:16:59Z We analyzed lake-bottom sediments from the Dry Valleys region of Antarctica to study the influence of water chemistry on the mineralogy and geochemistry of these sediments, as well as to evaluate techniques for remote spectral identification of potential biomarker minerals on Mars. Lakes from the Dry Valleys region of Antarctica have been investigated as possible analogs for extinct lake environments on early Mars. Sediment cores were collected in the present study from perennially ice-covered Lake Hoare in the Taylor Valley. These sediments were taken from a core in an oxic region of the lake and another core in an anoxic zone. Differences between the two cores were observed in the sediment color, Fe(II)/Fe(III) ratio, the presence of pyrite, the abundance of Fe, S, and some trace elements, and the C, N, and S isotope fractionation patterns. The results of visible-infrared reflectance spectroscopy (0.3-25 μm), Mössbauer spectroscopy (77 and 4 K), and X-ray diffraction are combined to determine the mineralogy and composition of these samples. The sediments are dominated by plagioclase, K-feldspar, quartz, and pyroxene. Algal mats grow on the bottom of the lake and organic material has been found throughout the cores. Calcite is abundant in some layers of the sediment core from the shallow, oxic region, and pyrite is abundant in the upper sediment layers of the core from the deep, anoxic region of Lake Hoare, Analysis of the spectroscopic features due to organics and carbonates with respect to the abundance of organic C and carbonate contents was performed in order to select optimal spectral bands for remote identification of these components in planetary regoliths. Carbonate bands near 4 and 6.8 μm (∼ 2500 and 1500 cm-1) were detected for carbonate abundances as low as 0.1 wt% CO2. Organic features at 3.38, 3.42, and 3.51 μm (2960, 2925, and 2850 cm-1) were detected for organic C abundances as low as 0.06 wt% C. The δ13C and δ15N trends show a more complex organic history for the anoxic region sediments than for ... Text Antarc* Antarctic Antarctica LSU Digital Commons (Louisiana State University) Antarctic Taylor Valley ENVELOPE(163.000,163.000,-77.617,-77.617) Hoare ENVELOPE(162.850,162.850,-77.633,-77.633) Lake Hoare ENVELOPE(162.850,162.850,-77.633,-77.633) Geochimica et Cosmochimica Acta 65 17 2875 2897 |
institution |
Open Polar |
collection |
LSU Digital Commons (Louisiana State University) |
op_collection_id |
ftlouisianastuir |
language |
unknown |
description |
We analyzed lake-bottom sediments from the Dry Valleys region of Antarctica to study the influence of water chemistry on the mineralogy and geochemistry of these sediments, as well as to evaluate techniques for remote spectral identification of potential biomarker minerals on Mars. Lakes from the Dry Valleys region of Antarctica have been investigated as possible analogs for extinct lake environments on early Mars. Sediment cores were collected in the present study from perennially ice-covered Lake Hoare in the Taylor Valley. These sediments were taken from a core in an oxic region of the lake and another core in an anoxic zone. Differences between the two cores were observed in the sediment color, Fe(II)/Fe(III) ratio, the presence of pyrite, the abundance of Fe, S, and some trace elements, and the C, N, and S isotope fractionation patterns. The results of visible-infrared reflectance spectroscopy (0.3-25 μm), Mössbauer spectroscopy (77 and 4 K), and X-ray diffraction are combined to determine the mineralogy and composition of these samples. The sediments are dominated by plagioclase, K-feldspar, quartz, and pyroxene. Algal mats grow on the bottom of the lake and organic material has been found throughout the cores. Calcite is abundant in some layers of the sediment core from the shallow, oxic region, and pyrite is abundant in the upper sediment layers of the core from the deep, anoxic region of Lake Hoare, Analysis of the spectroscopic features due to organics and carbonates with respect to the abundance of organic C and carbonate contents was performed in order to select optimal spectral bands for remote identification of these components in planetary regoliths. Carbonate bands near 4 and 6.8 μm (∼ 2500 and 1500 cm-1) were detected for carbonate abundances as low as 0.1 wt% CO2. Organic features at 3.38, 3.42, and 3.51 μm (2960, 2925, and 2850 cm-1) were detected for organic C abundances as low as 0.06 wt% C. The δ13C and δ15N trends show a more complex organic history for the anoxic region sediments than for ... |
format |
Text |
author |
Bishop, Janice L. Lougear, André Newton, Jason Doran, Peter T. Froeschl, Heinz Trautwein, Alfred X. Körner, Wilfried Koeberl, Christian |
spellingShingle |
Bishop, Janice L. Lougear, André Newton, Jason Doran, Peter T. Froeschl, Heinz Trautwein, Alfred X. Körner, Wilfried Koeberl, Christian Mineralogical and geochemical analyses of Antarctic lake sediments: A study of reflectance and Mössbauer spectroscopy and C, N, and S isotopes with applications for remote sensing on Mars |
author_facet |
Bishop, Janice L. Lougear, André Newton, Jason Doran, Peter T. Froeschl, Heinz Trautwein, Alfred X. Körner, Wilfried Koeberl, Christian |
author_sort |
Bishop, Janice L. |
title |
Mineralogical and geochemical analyses of Antarctic lake sediments: A study of reflectance and Mössbauer spectroscopy and C, N, and S isotopes with applications for remote sensing on Mars |
title_short |
Mineralogical and geochemical analyses of Antarctic lake sediments: A study of reflectance and Mössbauer spectroscopy and C, N, and S isotopes with applications for remote sensing on Mars |
title_full |
Mineralogical and geochemical analyses of Antarctic lake sediments: A study of reflectance and Mössbauer spectroscopy and C, N, and S isotopes with applications for remote sensing on Mars |
title_fullStr |
Mineralogical and geochemical analyses of Antarctic lake sediments: A study of reflectance and Mössbauer spectroscopy and C, N, and S isotopes with applications for remote sensing on Mars |
title_full_unstemmed |
Mineralogical and geochemical analyses of Antarctic lake sediments: A study of reflectance and Mössbauer spectroscopy and C, N, and S isotopes with applications for remote sensing on Mars |
title_sort |
mineralogical and geochemical analyses of antarctic lake sediments: a study of reflectance and mössbauer spectroscopy and c, n, and s isotopes with applications for remote sensing on mars |
publisher |
LSU Digital Commons |
publishDate |
2001 |
url |
https://digitalcommons.lsu.edu/geo_pubs/676 https://doi.org/10.1016/S0016-7037(01)00651-2 |
long_lat |
ENVELOPE(163.000,163.000,-77.617,-77.617) ENVELOPE(162.850,162.850,-77.633,-77.633) ENVELOPE(162.850,162.850,-77.633,-77.633) |
geographic |
Antarctic Taylor Valley Hoare Lake Hoare |
geographic_facet |
Antarctic Taylor Valley Hoare Lake Hoare |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
Faculty Publications |
op_relation |
https://digitalcommons.lsu.edu/geo_pubs/676 doi:10.1016/S0016-7037(01)00651-2 |
op_doi |
https://doi.org/10.1016/S0016-7037(01)00651-2 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
65 |
container_issue |
17 |
container_start_page |
2875 |
op_container_end_page |
2897 |
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1768380223376588800 |