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Anna Szynkiewicz - One of the best experts on this subject based on the ideXlab platform.
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the Polar sulfur cycle in the werenskioldbreen spitsbergen possible implications for understanding the deposition of sulfate minerals in the north Polar region of mars
Geochimica et Cosmochimica Acta, 2013Co-Authors: Anna Szynkiewicz, Magdalena Modelska, Sebastian Buczynski, David M Borrok, J P MerrisonAbstract:Abstract In this study we investigated the Polar cycling of sulfur (S) associated with the Werenskioldbreen glacier in Spitsbergen (Svalbard). Sulfide-derived S comprised 0.02–0.42 wt% of the fine-grained fraction of proglacial sediments. These sediments originated from glacial erosion of Precambrian sulfide-rich quartz and carbonate veins. In summer 2008, the δ 34 S of dissolved SO 4 in glacier melt waters (+9‰ to +17‰) was consistent with SO 4 generation from oxidation of primary sulfide minerals in the bedrock (+9‰ to +16‰). The calculated monthly SO 4 load was ∼6881 kg/month/km 2 in the main glacier stream. Subsequent evaporation and freezing of glacial waters lead to precipitation, accumulation, and temporary storage of sulfate salt efflorescences in the proglacial zone. These salts are presumably ephemeral, as they dissolve during annual snow/glacial melt events. Hydrated sulfates such as gypsum are also important constituents of the low-elevation areas around the Polar Ice Cap of Planum Boreum on Mars. The origin of this gypsum on Mars might be better understood by using the investigated Polar S cycle in Spitsbergen as a foundation. Assuming a trace sulfide content in the basaltic bedrock on Mars, the weathering of sulfides within the fine, porous texture of the ancient aeolian strata (basal unit) underlying Planum Boreum could have created elevated SO 4 fluxes (and gypsum precipitation) during episodic thawing/melting events in the past. Limited water activity and prevailing dry conditions on the surface of Mars are the likely factors that accounted for the larger accumulation and preservation of Polar gypsum on the surface and its broad aeolian distribution around Planum Boreum. This suggestion is also supported by an experiment showing that gypsum sand can be transported, under dry conditions, over great distances (∼2000 km) without a significant loss of mass.
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Origin of terrestrial gypsum dunes—Implications for Martian gypsum-rich dunes of Olympia Undae
Geomorphology, 2010Co-Authors: Anna Szynkiewicz, Ryan C. Ewing, Craig H. Moore, M. Glamoclija, David Bustos, Lisa M. PrattAbstract:Abstract The Estancia, White Sands, Guadalupe and Cuatrocienegas Dune Fields are among the largest known aeolian gypsum sand-dune accumulations on Earth and occupy closed-drainage basins within the Rio Grande Rift. High sedimentation rates of lacustrine gypsum occur in topographic depressions within the closed basins. The gypsum accumulations result from long-term, complex, interaction between tectonism, climate, and a hydrologic cycle that involves geochemical recycling of sulfur from older sedimentary rocks flanking and underlying the basins. Gypsum precipitation in lacustrine environments is strongly controlled by local groundwater/bedrock interaction. The ranges of δ34S values (per mil, vs. VCDT) for gypsum sand in the White Sands Dune Field (12.1 to 13.9‰), Guadalupe Dune Field (10.2 to 12.5‰) and Cuatrocienegas Dune Field (14.6 to 15.9‰) indicate that the main sources of dissolved sulfate are evaporite strata of Lower Permian, Middle Permian and Cretaceous ages, respectively. A spatial increase of δ34S values across the White Sands Dune Field, in the direction of prevailing winds, matches well with a stratigraphically upward increase of δ34S values recorded in Lake Otero (an ancient lake in the basin) strata. This finding supports previous suggestions that White Sands Dune Field evolved as a result of the step-wise deflation of previously stored sediments in Lake Otero. The modern gypsum dune fields are primarily wet eolian systems in which dune accumulation is controlled by a near-surface groundwater table, which promotes early cementation of the dune accumulations. Early cementation in the interdune surfaces and, to a lesser degree, on the dune surfaces reduces the amount of sand available for transport and slows rates of dune migration. Based on an average migration rate of 2 m/year, the time needed for a dune at White Sands to migrate the downwind distance of the dune field is approximately 6500 years, which matches well with other estimates of the initiation of the dune field at approximately 7000 years ago and indicates that White Sands likely evolved as a wet aeolian system. As on Earth, gypsum-rich dune fields apparently are rare on Mars. Gypsum has been identified only within the Olympia Undae Dune Field which encircles a portion of the Martian north Polar residual Ice Cap. Analogous to terrestrial gypsum dunes, the gypsum within the Olympia Undae gypsum-rich dunes might have originated from transport and deposition via aeolian processes. In this model, gypsum-rich source sediment could have been formed by confined groundwater or surface water activity and later transported by the wind. Any subsequent gypsum precipitation in the source area could have been initiated by episodic melting of the Martian Polar Ice Cap. It is likely that the gypsum was deposited in the Olympia Undae dunes after the main deflation events that led to formation of the siliciclastic components of the dune field.
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origin of terrestrial gypsum dunes implications for martian gypsum rich dunes of olympia undae
Geomorphology, 2010Co-Authors: Anna Szynkiewicz, Ryan C. Ewing, Craig H. Moore, M. Glamoclija, David Bustos, Lisa M. PrattAbstract:Abstract The Estancia, White Sands, Guadalupe and Cuatrocienegas Dune Fields are among the largest known aeolian gypsum sand-dune accumulations on Earth and occupy closed-drainage basins within the Rio Grande Rift. High sedimentation rates of lacustrine gypsum occur in topographic depressions within the closed basins. The gypsum accumulations result from long-term, complex, interaction between tectonism, climate, and a hydrologic cycle that involves geochemical recycling of sulfur from older sedimentary rocks flanking and underlying the basins. Gypsum precipitation in lacustrine environments is strongly controlled by local groundwater/bedrock interaction. The ranges of δ34S values (per mil, vs. VCDT) for gypsum sand in the White Sands Dune Field (12.1 to 13.9‰), Guadalupe Dune Field (10.2 to 12.5‰) and Cuatrocienegas Dune Field (14.6 to 15.9‰) indicate that the main sources of dissolved sulfate are evaporite strata of Lower Permian, Middle Permian and Cretaceous ages, respectively. A spatial increase of δ34S values across the White Sands Dune Field, in the direction of prevailing winds, matches well with a stratigraphically upward increase of δ34S values recorded in Lake Otero (an ancient lake in the basin) strata. This finding supports previous suggestions that White Sands Dune Field evolved as a result of the step-wise deflation of previously stored sediments in Lake Otero. The modern gypsum dune fields are primarily wet eolian systems in which dune accumulation is controlled by a near-surface groundwater table, which promotes early cementation of the dune accumulations. Early cementation in the interdune surfaces and, to a lesser degree, on the dune surfaces reduces the amount of sand available for transport and slows rates of dune migration. Based on an average migration rate of 2 m/year, the time needed for a dune at White Sands to migrate the downwind distance of the dune field is approximately 6500 years, which matches well with other estimates of the initiation of the dune field at approximately 7000 years ago and indicates that White Sands likely evolved as a wet aeolian system. As on Earth, gypsum-rich dune fields apparently are rare on Mars. Gypsum has been identified only within the Olympia Undae Dune Field which encircles a portion of the Martian north Polar residual Ice Cap. Analogous to terrestrial gypsum dunes, the gypsum within the Olympia Undae gypsum-rich dunes might have originated from transport and deposition via aeolian processes. In this model, gypsum-rich source sediment could have been formed by confined groundwater or surface water activity and later transported by the wind. Any subsequent gypsum precipitation in the source area could have been initiated by episodic melting of the Martian Polar Ice Cap. It is likely that the gypsum was deposited in the Olympia Undae dunes after the main deflation events that led to formation of the siliciclastic components of the dune field.
Lisa M. Pratt - One of the best experts on this subject based on the ideXlab platform.
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Origin of terrestrial gypsum dunes—Implications for Martian gypsum-rich dunes of Olympia Undae
Geomorphology, 2010Co-Authors: Anna Szynkiewicz, Ryan C. Ewing, Craig H. Moore, M. Glamoclija, David Bustos, Lisa M. PrattAbstract:Abstract The Estancia, White Sands, Guadalupe and Cuatrocienegas Dune Fields are among the largest known aeolian gypsum sand-dune accumulations on Earth and occupy closed-drainage basins within the Rio Grande Rift. High sedimentation rates of lacustrine gypsum occur in topographic depressions within the closed basins. The gypsum accumulations result from long-term, complex, interaction between tectonism, climate, and a hydrologic cycle that involves geochemical recycling of sulfur from older sedimentary rocks flanking and underlying the basins. Gypsum precipitation in lacustrine environments is strongly controlled by local groundwater/bedrock interaction. The ranges of δ34S values (per mil, vs. VCDT) for gypsum sand in the White Sands Dune Field (12.1 to 13.9‰), Guadalupe Dune Field (10.2 to 12.5‰) and Cuatrocienegas Dune Field (14.6 to 15.9‰) indicate that the main sources of dissolved sulfate are evaporite strata of Lower Permian, Middle Permian and Cretaceous ages, respectively. A spatial increase of δ34S values across the White Sands Dune Field, in the direction of prevailing winds, matches well with a stratigraphically upward increase of δ34S values recorded in Lake Otero (an ancient lake in the basin) strata. This finding supports previous suggestions that White Sands Dune Field evolved as a result of the step-wise deflation of previously stored sediments in Lake Otero. The modern gypsum dune fields are primarily wet eolian systems in which dune accumulation is controlled by a near-surface groundwater table, which promotes early cementation of the dune accumulations. Early cementation in the interdune surfaces and, to a lesser degree, on the dune surfaces reduces the amount of sand available for transport and slows rates of dune migration. Based on an average migration rate of 2 m/year, the time needed for a dune at White Sands to migrate the downwind distance of the dune field is approximately 6500 years, which matches well with other estimates of the initiation of the dune field at approximately 7000 years ago and indicates that White Sands likely evolved as a wet aeolian system. As on Earth, gypsum-rich dune fields apparently are rare on Mars. Gypsum has been identified only within the Olympia Undae Dune Field which encircles a portion of the Martian north Polar residual Ice Cap. Analogous to terrestrial gypsum dunes, the gypsum within the Olympia Undae gypsum-rich dunes might have originated from transport and deposition via aeolian processes. In this model, gypsum-rich source sediment could have been formed by confined groundwater or surface water activity and later transported by the wind. Any subsequent gypsum precipitation in the source area could have been initiated by episodic melting of the Martian Polar Ice Cap. It is likely that the gypsum was deposited in the Olympia Undae dunes after the main deflation events that led to formation of the siliciclastic components of the dune field.
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origin of terrestrial gypsum dunes implications for martian gypsum rich dunes of olympia undae
Geomorphology, 2010Co-Authors: Anna Szynkiewicz, Ryan C. Ewing, Craig H. Moore, M. Glamoclija, David Bustos, Lisa M. PrattAbstract:Abstract The Estancia, White Sands, Guadalupe and Cuatrocienegas Dune Fields are among the largest known aeolian gypsum sand-dune accumulations on Earth and occupy closed-drainage basins within the Rio Grande Rift. High sedimentation rates of lacustrine gypsum occur in topographic depressions within the closed basins. The gypsum accumulations result from long-term, complex, interaction between tectonism, climate, and a hydrologic cycle that involves geochemical recycling of sulfur from older sedimentary rocks flanking and underlying the basins. Gypsum precipitation in lacustrine environments is strongly controlled by local groundwater/bedrock interaction. The ranges of δ34S values (per mil, vs. VCDT) for gypsum sand in the White Sands Dune Field (12.1 to 13.9‰), Guadalupe Dune Field (10.2 to 12.5‰) and Cuatrocienegas Dune Field (14.6 to 15.9‰) indicate that the main sources of dissolved sulfate are evaporite strata of Lower Permian, Middle Permian and Cretaceous ages, respectively. A spatial increase of δ34S values across the White Sands Dune Field, in the direction of prevailing winds, matches well with a stratigraphically upward increase of δ34S values recorded in Lake Otero (an ancient lake in the basin) strata. This finding supports previous suggestions that White Sands Dune Field evolved as a result of the step-wise deflation of previously stored sediments in Lake Otero. The modern gypsum dune fields are primarily wet eolian systems in which dune accumulation is controlled by a near-surface groundwater table, which promotes early cementation of the dune accumulations. Early cementation in the interdune surfaces and, to a lesser degree, on the dune surfaces reduces the amount of sand available for transport and slows rates of dune migration. Based on an average migration rate of 2 m/year, the time needed for a dune at White Sands to migrate the downwind distance of the dune field is approximately 6500 years, which matches well with other estimates of the initiation of the dune field at approximately 7000 years ago and indicates that White Sands likely evolved as a wet aeolian system. As on Earth, gypsum-rich dune fields apparently are rare on Mars. Gypsum has been identified only within the Olympia Undae Dune Field which encircles a portion of the Martian north Polar residual Ice Cap. Analogous to terrestrial gypsum dunes, the gypsum within the Olympia Undae gypsum-rich dunes might have originated from transport and deposition via aeolian processes. In this model, gypsum-rich source sediment could have been formed by confined groundwater or surface water activity and later transported by the wind. Any subsequent gypsum precipitation in the source area could have been initiated by episodic melting of the Martian Polar Ice Cap. It is likely that the gypsum was deposited in the Olympia Undae dunes after the main deflation events that led to formation of the siliciclastic components of the dune field.
M. Balme - One of the best experts on this subject based on the ideXlab platform.
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Modeled subglacial water flow routing supports localized intrusive heating as a possible cause of basal melting of Mars' south Polar Ice Cap
Journal of Geophysical Research. Planets, 2019Co-Authors: N. Arnold, S. Conway, F. Butcher, M. BalmeAbstract:The discovery of an ~20‐km‐wide area of bright subsurface radar reflections, interpreted as liquid water, beneath the Martian south Polar layered deposits (SPLD) in data from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument, and the discovery of two geologically recent potential eskers (landforms produced by subglacial melt) associated with viscous flow features in Martian midlatitudes, has suggested recent basal melting of Martian Ice deposits may be feasible, possibly due to locally elevated geothermal heating. Locations of terrestrial subglacial lakes and major drainage axes have been successfully predicted from subglacial hydraulic potential surfaces calculated from surface topography and Ice thickness. Here, we use surface topography from the Mars Orbiter Laser Altimeter and SPLD bed elevations derived from MARSIS data to calculate the subglacial hydraulic potential surface beneath the SPLD and determine whether the observed high reflectance area coincides with predicted subglacial lake locations. Given the sensitivity of terrestrial predictions of lake locations to basal topography, we derive over 1,000 perturbed topographies (using noise statistics from the MARSIS data) to infer the most likely locations of possible subglacial water bodies and drainage axes. Our results show that the high reflectance area does not coincide with any substantial predicted lake locations; three nearby lake locations are robustly predicted however. We interpret this result as suggesting that the high reflectance area (assuming the interpretation as liquid is correct) is most likely a hydraulically isolated patch of liquid confined by the surrounding cold‐based Ice, rather than a topographically‐constrained subglacial lake.
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Code and Data Readme for “Modeled subglacial water flow routing supports localized intrusive heating as a possible cause of basal melting of Mars’ south Polar Ice Cap"
2019Co-Authors: N. Arnold, Frances E.g. Butcher, Susan J. Conway, M. BalmeAbstract:Computer code and derived data developed during the research reported in "Modeled subglacial water flow routing supports localized intrusive heating as a possible cause of basal melting of Mars’ south Polar Ice Cap" published in Journal of Geophysical Research-Planets. See the file 'Code and Data Readme.rtf' for detailed information about the contents of this dataset.
N. Arnold - One of the best experts on this subject based on the ideXlab platform.
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Modeled subglacial water flow routing supports localized intrusive heating as a possible cause of basal melting of Mars' south Polar Ice Cap
Journal of Geophysical Research. Planets, 2019Co-Authors: N. Arnold, S. Conway, F. Butcher, M. BalmeAbstract:The discovery of an ~20‐km‐wide area of bright subsurface radar reflections, interpreted as liquid water, beneath the Martian south Polar layered deposits (SPLD) in data from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument, and the discovery of two geologically recent potential eskers (landforms produced by subglacial melt) associated with viscous flow features in Martian midlatitudes, has suggested recent basal melting of Martian Ice deposits may be feasible, possibly due to locally elevated geothermal heating. Locations of terrestrial subglacial lakes and major drainage axes have been successfully predicted from subglacial hydraulic potential surfaces calculated from surface topography and Ice thickness. Here, we use surface topography from the Mars Orbiter Laser Altimeter and SPLD bed elevations derived from MARSIS data to calculate the subglacial hydraulic potential surface beneath the SPLD and determine whether the observed high reflectance area coincides with predicted subglacial lake locations. Given the sensitivity of terrestrial predictions of lake locations to basal topography, we derive over 1,000 perturbed topographies (using noise statistics from the MARSIS data) to infer the most likely locations of possible subglacial water bodies and drainage axes. Our results show that the high reflectance area does not coincide with any substantial predicted lake locations; three nearby lake locations are robustly predicted however. We interpret this result as suggesting that the high reflectance area (assuming the interpretation as liquid is correct) is most likely a hydraulically isolated patch of liquid confined by the surrounding cold‐based Ice, rather than a topographically‐constrained subglacial lake.
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Code and Data Readme for “Modeled subglacial water flow routing supports localized intrusive heating as a possible cause of basal melting of Mars’ south Polar Ice Cap"
2019Co-Authors: N. Arnold, Frances E.g. Butcher, Susan J. Conway, M. BalmeAbstract:Computer code and derived data developed during the research reported in "Modeled subglacial water flow routing supports localized intrusive heating as a possible cause of basal melting of Mars’ south Polar Ice Cap" published in Journal of Geophysical Research-Planets. See the file 'Code and Data Readme.rtf' for detailed information about the contents of this dataset.
Jon D. Pelletier - One of the best experts on this subject based on the ideXlab platform.
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How do spiral troughs form on Mars
Geology, 2004Co-Authors: Jon D. PelletierAbstract:A three-dimensional model for the coupled evolution of Ice-surface temperature and elevation in the Martian Polar Ice Caps is presented. The model includes [(1)][1] enhanced heat absorption on steep, dust-exposed scarps, [(2)][2] accumulation and ablation, and [(3)][3] lateral conduction of heat within the Ice Cap. The model equations are similar to classic equations for excitable media, including nerve fibers and chemical oscillators. In two dimensions, a small zone of initial melting in the model develops into a train of poleward-migrating troughs with widths similar to those observed on Mars. Starting from random initial conditions, the three-dimensional model reproduces spiral waves very similar to those in the north Polar Ice Cap, including secondary features such as gull-wing–shaped troughs, bifurcations, and terminations. These results suggest that eolian processes and Ice flow may not control trough morphology. [1]: #disp-formula-1 [2]: #disp-formula-2 [3]: #disp-formula-3
