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Most western Arabia Terra dark streaks appear at MOC NA image scales to be thin veneers superposed on a previously mantled surface. (a) MOC WA context image M07-00741 showing location of NA subframe at margin of dark streak near 8.8°N, 346.9°W. (b) NA image M07-00740 of streak margin. There is little difference between the light and dark mantle surfaces except their albedo. Both images are illuminated from the lower left.
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High spatial resolution (1.5 to 6 m/pixel) Mars Global Surveyor Mars Orbiter Camera images obtained September 1997 to June 2001 show that each of the large, dark wind streaks of western Arabia Terra originate at a barchan dune field on a crater floor. The streaks consist of a relatively thin (<1 m) coating of sediment deflated from the dune fields...
Citations
... We measured orientations of these features and found them to be consistent across all sites in both craters with a formative wind direction to the northwest, assuming the "horns" of the crescents are oriented downwind ( Figure S6 in Supporting Information S1). This is markedly different from the modern wind regime in western Arabia Terra, which is dominated by winds to the south and southwest, inferred by wind streaks, modern barchan dunes, the orientation of eroded outcrops and yardangs, and Global Circulation Models (GCMs) (Dorn & Day, 2020;Edgett, 2002;Fenton & Richardson, 2001;Rodriguez et al., 2010;Silvestro et al., 2011). Alternatively, the orientation could be explained by recirculation within the crater inducing a reversed flow at the surface, allowing for a regional wind direction more similar to present-day patterns. ...
Layered rocks in the Arabia Terra region of Mars preserve a record of the planet's ancient climate. However, the exact formation mechanism of these rhythmically layered deposits is currently unknown. We previously proposed two distinct regionally correlative units of the Arabia Terra layered deposits based on their bedding thicknesses, orientation, and morphology from High Resolution Imaging Science Experiment stereo observations. For this work, we selected two adjacent craters in Arabia Terra, Sera and Jiji, for further study to test the proposed stratigraphic correlation. We constructed vertical stratigraphic sections of the deposits from dip‐corrected bed thickness measurements and local stratigraphic correlations. We found that individual beds maintain a consistent thickness over kilometer scales but are somewhat variable at the basin scale. Each crater exhibited strata with a thinning‐upward trend that terminated at terraces with inconsistent bedding, possibly indicating an equilibrium elevation for the formation mechanism. We also identified a probable stratigraphic correlation between basins using the similarities in bedding characteristics and patterns of measurable differences in bed‐to‐bed thicknesses, indicating synchronous strata. The planar bedding and uniform thickness of the beds within the deposits are consistent with airfall deposition over a prolonged geologic period. This process likely occurred under comparably dry conditions relative to the previously proposed depositional and diagenetic formation mechanisms.
... Although there are north-south yardangs present on the ELD Mound (predominantly on the mound's south side), a north-south wind direction is at odds with the present mound shape (Figure 15). North-south wind streaks on the plateau adjacent to many craters of western Arabia Terra (including Becquerel) have been demonstrated previously to be comprised of mixed material with their connection to eroded ELD material undetermined (Edgett, 2002). Mapping of wind streaks in Arabia Terra has also demonstrated that craters with layered mounds do not always have an adjacent wind streak (Fergason & Christensen, 2008). ...
The formation of layered mounds on Mars remains a major topic of debate, with the relationship between their deposition and chemical alteration a major aspect still to be constrained. The association these deposits have with hydrated minerals indicates aqueous processes were active in their past, however the extent and duration of this aqueous period has yet to be fully realized. We studied compositional, stratigraphical, and structural characteristics of two separate layered deposits within Becquerel crater, Arabia Terra, to constrain their origins and the intensity of past aqueous activity. We find that due to key differences in composition, layering, and deformation between the two deposits, the timing of important depositional changes within Becquerel can be identified. We propose a scenario involving differences in fluid expulsion intensity and water level between the two layered deposits, in which diverse depositional and post‐depositional environments were able to form. Furthermore, internal collapsing and deformation of the main mound might reflect that fluid upwelling persisted below the mound after formation. Determining the relationship between these two deposits is an important step in unraveling the past climate of Arabia Terra, and more broadly Mars. The evidence of protracted fluid expulsion represents a unique opportunity for future missions searching for signs of past life.
... Collectively, sand distribution patterns and dune morphologies within Gale crater are consistent with overall net-southward migration of crater floor sands, despite pathways that deflect around Aeolis Mons and that are complicated by nighttime slope winds Day & Kocurek, 2016). Despite destructive interference at the southern crater rim between regional winds prevailing from the N and more local katabatic (nighttime downslope) winds from the S, some material ultimately is evacuated southward out of the crater to form a prominent low-albedo wind streak that extends southward >100 km (Anderson & Bell, 2010;Day & Kocurek, 2016), similar to many other martian crater wind streaks (Edgett, 2002;Thomas, 1984). This model is consistent with the net-SW and -SE migration of bedforms in the NW and NE regions of the crater (respectively) inferred by dune morphologies (Day & Kocurek, 2016), observed from orbit (Bridges et al., 2017;Silvestro et al., 2013Silvestro et al., , 2016, and recorded from the surface . ...
... Interactions between martian crater rim topography, regional wind patterns, and thermally driven slope winds cause modern sediments to accumulate on crater floors and evacuate from craters to form wind streaks (e.g., Edgett, 2002;Fenton, 2005;Thomas, 1984). Various combinations of aeolian emplacement, erosion, and evacuation of sediments also have been proposed to explain central mounds within many ancient craters (e.g., Anderson & Bell, 2010;Kite et al., 2013;Malin & Edgett, 2000;Steele et al., 2018;Thomson et al., 2011). ...
The Mars Science Laboratory (MSL) rover spent a full martian year exploring the phyllosilicate‐bearing Glen Torridon trough on the flank of Aeolis Mons in Gale crater, enabling in‐depth assessment of aeolian processes. MSL encountered erosional and depositional features recording a long aeolian history. The trough has served as a long‐term conduit for sand transport, probably involving many cycles of sand accumulation and deflation. Rock abrasion textures indicate sand‐driving winds blowing W‐SW (opposite of abrasion textures on the Greenheugh Pediment above the trough floor). Indurated megaripple surfaces with 2–5 mm grains contrast with seasonally active ripples having finer maximum grain sizes, indicating more vigorous saltation in the past. Active ripples display a broad continuum of wavelengths, as well as coarser grains at crests than troughs, consistent with origins as impact ripples. Orientations of a wind streak extending from a large ripple field, and sandy wind tails behind obstacles, indicate sand is driven W‐SW in the current era, approximately along the trough axis. Erosion of drill tailings piles was strongly seasonal, enhanced during late spring and early summer (perihelion). Climate modeling suggests W‐SW sand transport can be attributed to seasonal enhancement of nighttime regional winds entering Gale crater from the N, combined with local katabatic winds flowing down the slopes of Aeolis Mons. However, it is unclear whether sand transport at Glen Torridon is primarily from these wind components combining and acting simultaneously, or occurring in serial at different times of night; field evidence supports both possibilities.
... However, the presence of thin dark streaks on the southeastern boundary suggests a different scenario. Based on the relation between dark streaks, dunes, and subjacent terrain, the dark streaks are interpreted as the result of wind activities (Edgett 2002). Gusts of wind can blow the materials out and result in streaks of deposited sands (Thomas et al. 1981;Geissler et al. 2008) toward the downwind direction (west−northwest) into the dune field. ...
... Gusts of wind can blow the materials out and result in streaks of deposited sands (Thomas et al. 1981;Geissler et al. 2008) toward the downwind direction (west−northwest) into the dune field. Thus, the simplest explanation of these dark streaks can be the indication of the prevalence of wind activities (Edgett 2002) within the crater and mobilization of the dune materials. Along the dune faces, near the crests on the western boundary, appear to be mega-ripples (i.e., TARs) spaced several meters apart. ...
We analyze thermal emission spectra using the 2001 Mars Odyssey Thermal Emission Imaging System and the Mars Global Surveyor Thermal Emission Spectrometer to characterize grain size and mineralogical composition of dunes at Hargraves crater, Mars. Thermal inertia and bulk composition of the dunes were compared to inferred provenances from the thermal infrared response of surface constituent materials. We use a Markov Chain Monte Carlo technique to estimate the bulk amount of mineralogy contributed by each inferred provenance to the dune field composition. An average thermal inertia value of 238 ± 17 Jm ⁻² K ⁻¹ s −0.5 was found for the dunes, corresponding to a surface composed of an average effective grain size of ∼391 ± 172 μ m. This effective particle size suggests the presence of mostly medium sand-sized materials mixed with fine and coarse grain sands. The dunes are likely composed of a weakly indurated surface mixed with unconsolidated materials. Compositional analysis specifies that the dunes are composed of a mixture of feldspar, olivine, pyroxene, and relatively low bulk-silica content. Dune materials were likely derived from physical weathering, especially aeolian erosion, predominantly from the crater ejecta unit at the crater, mixed with a small amount from the crater floor and crater rim and wall lithologies—indicating that the dune materials were likely sourced locally.
... Early studies using data from the previous Mariner 9 and Viking orbiters, plus the recent MGS, Mars Express, and MRO missions, described the distribution, morphology, composition, thermophysical characteristics, possible origins, and mobility of dark-toned sand dunes on Mars (Arvidson, 1974;Banks et al., 2018;Chojnacki et al., 2011;Chojnacki, Burr, Moersch, & Wray, 2014;Christensen, 1983;Cutts & Smith, 1973;Edgett, 2002;Edgett & Christensen, 1994;Edgett & Malin, 2000;Fenton, 2020;Fenton et al., 2019;Hayward et al., 2007Hayward et al., , 2014Sagan et al., 1972;P. Thomas, 1982P. ...
Ripples, transverse aeolian ridges (TARs), and dark‐toned sand sheets and dunes are common aeolian bedforms on the Martian surface. They are important for understanding the nature of present‐day Martian sediments and regional aeolian processes. Here we present a case study investigation of ripples, TARs, a dark‐toned sand sheet, and dunes in an unnamed—but well‐covered by remote sensing datasets—crater in Terra Sabaea, Mars, to consider their nature and possible origin scenarios. Repeat high‐spatial resolution images show only minor albedo changes among the dark‐toned sand dunes but no obvious changes in the ripples and TARs. Visible and infrared spectra show that the megaripples and TARs are pyroxene‐bearing, while the dark‐toned sheet and dunes are olivine‐bearing. Thousands of TARs are superimposed on the crater walls, and they have a similar composition as the bedrock exposed around the central pit, suggesting that some percentage of the sediment composing the TARs may be locally derived. Megaripples have a similar composition as TARs, suggesting they may share a similar origin. Dark‐toned sand sheets and sand dunes show a different composition from the substrate of the crater, plus bedform orientations indicative of a dominant, north‐northwest wind, indicating that some of these dark sands might have been blown in from outside of the crater. Alternatively, the sand in the megaripples, TARs, sand sheets, and dunes could share a common source, and some or even all of them could be recycled from the weathering and erosion of the sand‐bearing clastic rocks exposed in the crater walls.
... Based on analogy with the wind streaks associated with craters in western Arabia Terra (Edgett, 2002), the streak emanating from southern Gale crater might consist of silt-to fine sand-sized sediment that came from the erosion of rocks inside the crater. The wind streak covers ~45,000 km 2 . ...
Extraformational sediment recycling (old sedimentary rock to new sedimentary rock) is a fundamental aspect of Earth's geological record; tectonism exposes sedimentary rock, whereupon it is weathered and eroded to form new sediment that later becomes lithified. On Mars, tectonism has been minor, but two decades of orbiter instrument-based studies show that some sedimentary rocks previously buried to depths of kilometers have been exposed, by erosion, at the surface. Four locations in Gale crater, explored using the National Aeronautics and Space Administration's Curiosity rover, exhibit sedimentary lithoclasts in sedimentary rock: At Marias Pass, they are mudstone fragments in sandstone derived from strata below an erosional unconformity; at Bimbe, they are pebble-sized sandstone and, possibly, laminated, intraclast-bearing, chemical (calcium sulfate) sediment fragments in conglomerates; at Cooperstown, they are pebble-sized fragments of sandstone within coarse sandstone; at Dingo Gap, they are cobble-sized, stratified sandstone fragments in conglomerate derived from an immediately underlying sandstone. Mars orbiter images show lithified sediment fans at the termini of canyons that incise sedimentary rock in Gale crater; these, too, consist of recycled, extraformational sediment. The recycled sediments in Gale crater are compositionally immature, indicating the dominance of physical weathering processes during the second known cycle. The observations at Marias Pass indicate that sediment eroded and removed from craters such as Gale crater during the Martian Hesperian Period could have been recycled to form new rock elsewhere. Our results permit prediction that lithified deltaic sediments at the Perseverance (landing in 2021) and Rosalind Franklin (landing in 2023) rover field sites could contain extraformational recycled sediment.
... Geomorphic evidence of surface-wind interactions is abundant on Mars and includes aeolian bedforms (Balme et al., 2008;Ewing & Kocurek, 2010;Hayward et al., 2014), yardangs (Urso et al., 2018;Ward, 1979;Zimbelman & Griffin, 2010), wind streaks (Edgett, 2002;Lee, 1984;Veverka et al., 1981), and dust devil tracks (Greeley et al., 2006). In particular, dunes and wind streaks commonly interact with crater topography and provide a mechanism to study how wind and sediment transport interact with these local depocenters. ...
... Craters studied within this work demonstrate a range of interactions between aeolian sand and dust transport and crater basin topography. Each crater, by requirement, is occupied by a low albedo dune field interpreted as evidence that actively saltating sands are available within the crater basin (Bridges et al., 2017;Chojnacki et al., 2011Chojnacki et al., , 2015Edgett, 2002;Silvestro et al., 2010). Around half of the studied craters are associated with either a low or high albedo wind streak, indicating that, in these instances, some sediment is transported out of the crater. ...
Craters are the most prevalent basins and potential depocenters of sediment on Mars. Within these craters and extending from them, terminal dune fields and wind streaks are abundant, indicating active sediment transport and providing a way to study how wind and sediment interact with crater topography. Here we explore the role of craters as both sources and sinks in the modern Martian sedimentary cycle. Our results show that craters with low albedo wind streaks (indicative of sediment transport out of a crater and downwind dust removal) have lower crater wall slopes (9.4° ± 5.5°) compared to craters without wind streaks (17° ± 5.8°). We interpret that crater wall slopes play a dominant role in whether sediment is transported out of a crater basin and infer, from measurements of craters on Mars, that a crater transitions from being a net sediment sink to a net sediment source when crater wall slopes decrease to ~15°. This threshold value is consistent with limits of bedform climb observed on Earth and elsewhere on Mars.
... Southeast to northwest sediment transport follows the continental-scale topographic gradient from highland toward lowland terrain on modern Mars, and the dune strata in this area may preserve evidence of an aeolian transport corridor that brought sediment to the northern lowlands. The interpreted northwestward transport differs from modern aeolian transport pathways across Arabia Terra, which have been interpreted from dune-field scale surface features to be toward the southwest (Edgett, 2002;Silvestro et al., 2011). Southwestward transport is consistent with modern single cell atmospheric circulation driving wind toward the equator and deflecting to the west in response to Coriolis forces (Leovy & Mintz, 1969). ...
Ancient lacustrine and aeolian sediments have been separately identified in a variety of locations on Mars. In this work, we interpret the depositional history of Barth crater and its surrounding area in Arabia Terra where exposed geologic units preserve a record of lacustrine and aeolian interaction. Aeolian sandstone in the study area overlies lacustrine strata and is interbedded with easily eroded interdune deposits. The aeolian sandstone preserves dune strata with structures that indicate paleo‐sediment transport toward the northwest. The aeolian unit also preserves a transition up‐section from separated barchan dunes to continuous transverse dunes, capturing the development of the ancient dune field from sediment limited to sediment rich. Inverted fluvial channels provide evidence that water was delivered to the area at the same time the dune field was present, providing a simple mechanism, via wetting and cementation, for aeolian strata preservation. This example of wet‐system aeolian accumulation preserves an upward drying sequence in the sedimentary record that may have been coincident with the widely hypothesized global climate transition. The terrains described in this work provide a framework for interpreting similar aeolian units in elsewhere on Mars, even where cross‐strata cannot be easily resolved.
... Noteworthy among these, there are Gale crater (Hobbs et al., 2010;Silvestro et al., 2013;Wray, 2013;Bridges et al., 2014;Sefton-Nash et al., 2014;Vaz et al., 2015;Day and Kocurek, 2016;Chojnacki and Fenton, 2017;Banham et al., 2018) Herschel and Moreux craters (Cardinale et al., 2012(Cardinale et al., , 2016Runyon et al., 2017a-b) as well as Martian polar layered deposits (Howard, 2000) and Meridiani Planum (Golombek et al., 2006(Golombek et al., , 2010Hayes et al., 2011;Chojnacki et al., 2015, Chojnacki andFenton, 2017;Silvestro et al., 2015). First studies on the potential sand sources by Edgett (2002) and Fenton (2005Fenton ( , 2008 revealed evidences of potential local sources of dark sand from layers exposed in several craters in Arabia and Noachis Terrae. Recent analysis carried out by Chojnacki et al. (2014) highlighted that Valles Marineris dunes derive from diverse regional and local sediment sources. ...
Our research focuses on the detailed study of the aeolian deposits within Moreux crater using multi-resolution imaging and spectral data from the Mars Reconnaissance Orbiter. The morphometric analysis on the dune slip faces and wind streak orientations allowed us to reconstruct the sand transport pathways and the changes of the transport pattern. We used a new automatic procedure based on the Line Detection algorithm in PCI Geomatics’ Geomatica software to characterize small scale aeolian structures as ripples within Moreux crater from HiRISE images. After validation on a previously studied area in Herschel crater, we apply this method to reconstruct the wind regime at high spatial resolution in Moreux and reconstruct the wind circulation forming the aeolian bedforms. Moreover, we used three pairs of CTX images to perform a multi-temporal analysis of the wind streaks. We mapped more than 500 features with data acquisition spanning over four Earth years and the observed wind streak changes may reflect present day atmospheric variations due to local winds. CRISM datasets show an olivine and clinopyroxene mixture characterizing most of the dunes within Moreux crater, while the dark dunes in the northern sector of the crater showed an enrichment in Mg-olivine. This composition is similar to that detected in the central peak bedrock suggesting that central peak erosion contributes to the formation of the northly dunes meanwhile recent northeast wind flows and Moreux topography influence the wind circulation and determine the formation of the sand transport pathways within the crater. These results are consistent with the hypothesis that aeolian sands are generally sourced locally on Mars.
... The low albedo has been interpreted to indicate the presence of mafic minerals (Cutts and Smith 1973), and a basaltic composition (Jaumann et al., 2006, Tirsch et al., 2011. In a study of low-albedo surfaces in western Arabia Terra, Edgett (2002) noted that the relations between dunes, wind streaks and subjacent areas implies that dark-toned grains, finer than those that comprise dunes, are lifted into suspension and deposited downwind. Spectral analysis of the dark dunes and sand sheets on Mars by Tirsch et al. (2011) indicates that they nearly all have the same mafic composition and that they are most likely to be derived from volcanic rocks. ...
Dust is nearly ubiquitous on Mars, covering much of the planet’s surface, having been redistributed by dust storms. Analysis of dust via landed instrumentation indicates a basaltic composition for its protolith; the same is interpreted for the dark dune sands encountered at rover field sites. In this paper, we used samples of aeolian sands derived from basaltic volcanoes in an experiment to simulate dust production from basalt dune sands within an abrasion chamber. In addition, we used samples from gypsum dunes because gypsum is found within dune fields on the northern plains of Mars. The results, expressed as weight % of sample reduced to dust, show a remarkably broad range over four orders of magnitude. Aeolian abrasion of basalt sands can produce similar amounts of dust, as is the case for some desert sands on Earth. Some plausible Mars analogue materials can produce large amounts of dust, suggesting that aeolian movement of basaltic sand, and volcanic sediments on the surface of Mars is a potential source of fine-grained sediment or dust.
