Origin and significance of decameter-scale polygons in the lower Peace Vallis fan of Gale crater, Mars
Decameter-scale polygons are extensively developed in the Bedded Fractured (BF) Unit of the lower Peace Vallis fan. The polygons occur in a likely extension of the Gillespie Lake Member, north of Yellowknife Bay, the section first drilled by the Mars Science Laboratory (MSL) mission. We examine hypo...
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Online Access: | http://hdl.handle.net/10261/184473 https://doi.org/10.1016/j.icarus.2016.04.038 https://doi.org/10.13039/100006961 https://doi.org/10.13039/501100000781 https://doi.org/10.13039/501100002830 https://doi.org/10.13039/100006203 |
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ftcsic:oai:digital.csic.es:10261/184473 2024-02-11T10:09:27+01:00 Origin and significance of decameter-scale polygons in the lower Peace Vallis fan of Gale crater, Mars Oehler, Dorothy Z. Mangold, Nicolas Hallet, Bernat Fairén, Alberto G. Le Deit, Laetitia Williams, Amy J. Sletten, Ronald S. Martínez-Frías, J. Johnson Space Center NASA Astrobiology Institute (US) Centre National D'Etudes Spatiales (France) California Institute of Technology European Research Council 2016-10 http://hdl.handle.net/10261/184473 https://doi.org/10.1016/j.icarus.2016.04.038 https://doi.org/10.13039/100006961 https://doi.org/10.13039/501100000781 https://doi.org/10.13039/501100002830 https://doi.org/10.13039/100006203 en eng Elsevier https://doi.org/10.1016/j.icarus.2016.04.038 Sí Icarus 277: 56-72 (2016) 0019-1035 http://hdl.handle.net/10261/184473 doi:10.1016/j.icarus.2016.04.038 http://dx.doi.org/10.13039/100006961 http://dx.doi.org/10.13039/501100000781 http://dx.doi.org/10.13039/501100002830 http://dx.doi.org/10.13039/100006203 none Mars Mars climate Mars surface artículo http://purl.org/coar/resource_type/c_6501 2016 ftcsic https://doi.org/10.1016/j.icarus.2016.04.03810.13039/10000696110.13039/50110000078110.13039/50110000283010.13039/100006203 2024-01-16T10:40:35Z Decameter-scale polygons are extensively developed in the Bedded Fractured (BF) Unit of the lower Peace Vallis fan. The polygons occur in a likely extension of the Gillespie Lake Member, north of Yellowknife Bay, the section first drilled by the Mars Science Laboratory (MSL) mission. We examine hypotheses for the origin of these polygons to provide insight into the history of Gale crater. The polygons are ∼4–30 m across, square to rectangular, and defined by ∼0.5–4 m wide, generally straight troughs with orthogonal intersections. Polygon networks are typically oriented-orthogonal systems, with occasional nearly circular patterns, hundreds of meters across. Potential origins include cooling of lava, and for sedimentary units, syneresis, unloading, weathering, desiccation, impact processes, and cold-climate thermal contraction. Cold-climate thermal contraction is the hypothesis most consistent with the sedimentary nature of the BF Unit and the polygon morphology, geometry, networks, and apparent restriction to the coarse-grained Gillespie Lake Member. A periglacial setting further provides the best analogs for the circular networks and is consistent with geologic context and MSL data. Most of the decametric polygons appear to be ancient. They are confined to the Hesperian BF Unit, and only a few of their bounding fractures extend into younger or recently exposed units. In this regard, they differ from the majority of proposed thermal-contraction polygons on Mars, as those are generally thought to be young features, and, accordingly, the history of formation, preservation and reactivation of the decametric polygons is likely to be more complex than that of any proposed young polygons on Mars. The decametric polygons in the BF Unit may represent landforms developed in a cold but still comparatively wet interlude between a clement early Mars and the much drier and colder planet of today. DZO was supported by the Astromaterials Research and Exploration Science (ARES) Division at Johnson Space Center and the NASA ... Article in Journal/Newspaper Yellowknife Digital.CSIC (Spanish National Research Council) Yellowknife Yellowknife Bay ENVELOPE(-114.336,-114.336,62.367,62.367) Icarus 277 56 72 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
topic |
Mars Mars climate Mars surface |
spellingShingle |
Mars Mars climate Mars surface Oehler, Dorothy Z. Mangold, Nicolas Hallet, Bernat Fairén, Alberto G. Le Deit, Laetitia Williams, Amy J. Sletten, Ronald S. Martínez-Frías, J. Origin and significance of decameter-scale polygons in the lower Peace Vallis fan of Gale crater, Mars |
topic_facet |
Mars Mars climate Mars surface |
description |
Decameter-scale polygons are extensively developed in the Bedded Fractured (BF) Unit of the lower Peace Vallis fan. The polygons occur in a likely extension of the Gillespie Lake Member, north of Yellowknife Bay, the section first drilled by the Mars Science Laboratory (MSL) mission. We examine hypotheses for the origin of these polygons to provide insight into the history of Gale crater. The polygons are ∼4–30 m across, square to rectangular, and defined by ∼0.5–4 m wide, generally straight troughs with orthogonal intersections. Polygon networks are typically oriented-orthogonal systems, with occasional nearly circular patterns, hundreds of meters across. Potential origins include cooling of lava, and for sedimentary units, syneresis, unloading, weathering, desiccation, impact processes, and cold-climate thermal contraction. Cold-climate thermal contraction is the hypothesis most consistent with the sedimentary nature of the BF Unit and the polygon morphology, geometry, networks, and apparent restriction to the coarse-grained Gillespie Lake Member. A periglacial setting further provides the best analogs for the circular networks and is consistent with geologic context and MSL data. Most of the decametric polygons appear to be ancient. They are confined to the Hesperian BF Unit, and only a few of their bounding fractures extend into younger or recently exposed units. In this regard, they differ from the majority of proposed thermal-contraction polygons on Mars, as those are generally thought to be young features, and, accordingly, the history of formation, preservation and reactivation of the decametric polygons is likely to be more complex than that of any proposed young polygons on Mars. The decametric polygons in the BF Unit may represent landforms developed in a cold but still comparatively wet interlude between a clement early Mars and the much drier and colder planet of today. DZO was supported by the Astromaterials Research and Exploration Science (ARES) Division at Johnson Space Center and the NASA ... |
author2 |
Johnson Space Center NASA Astrobiology Institute (US) Centre National D'Etudes Spatiales (France) California Institute of Technology European Research Council |
format |
Article in Journal/Newspaper |
author |
Oehler, Dorothy Z. Mangold, Nicolas Hallet, Bernat Fairén, Alberto G. Le Deit, Laetitia Williams, Amy J. Sletten, Ronald S. Martínez-Frías, J. |
author_facet |
Oehler, Dorothy Z. Mangold, Nicolas Hallet, Bernat Fairén, Alberto G. Le Deit, Laetitia Williams, Amy J. Sletten, Ronald S. Martínez-Frías, J. |
author_sort |
Oehler, Dorothy Z. |
title |
Origin and significance of decameter-scale polygons in the lower Peace Vallis fan of Gale crater, Mars |
title_short |
Origin and significance of decameter-scale polygons in the lower Peace Vallis fan of Gale crater, Mars |
title_full |
Origin and significance of decameter-scale polygons in the lower Peace Vallis fan of Gale crater, Mars |
title_fullStr |
Origin and significance of decameter-scale polygons in the lower Peace Vallis fan of Gale crater, Mars |
title_full_unstemmed |
Origin and significance of decameter-scale polygons in the lower Peace Vallis fan of Gale crater, Mars |
title_sort |
origin and significance of decameter-scale polygons in the lower peace vallis fan of gale crater, mars |
publisher |
Elsevier |
publishDate |
2016 |
url |
http://hdl.handle.net/10261/184473 https://doi.org/10.1016/j.icarus.2016.04.038 https://doi.org/10.13039/100006961 https://doi.org/10.13039/501100000781 https://doi.org/10.13039/501100002830 https://doi.org/10.13039/100006203 |
long_lat |
ENVELOPE(-114.336,-114.336,62.367,62.367) |
geographic |
Yellowknife Yellowknife Bay |
geographic_facet |
Yellowknife Yellowknife Bay |
genre |
Yellowknife |
genre_facet |
Yellowknife |
op_relation |
https://doi.org/10.1016/j.icarus.2016.04.038 Sí Icarus 277: 56-72 (2016) 0019-1035 http://hdl.handle.net/10261/184473 doi:10.1016/j.icarus.2016.04.038 http://dx.doi.org/10.13039/100006961 http://dx.doi.org/10.13039/501100000781 http://dx.doi.org/10.13039/501100002830 http://dx.doi.org/10.13039/100006203 |
op_rights |
none |
op_doi |
https://doi.org/10.1016/j.icarus.2016.04.03810.13039/10000696110.13039/50110000078110.13039/50110000283010.13039/100006203 |
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Icarus |
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277 |
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