Mawrth Vallis, generally counted among Mars’ giant outflow channels, has an atypical geomorphology that is less well-studied than its coinciding, thick (>150m) clay-bearing deposits. Here, we present ongoing work as part of the PLANMAP project to map the geomorphic features along the length of Mawrth Vallis in addition to a detailed map of the channel adjacent to the ExoMars 2018 landing ellipse to establish its history of erosion and deposition and relationship with the clay-bearing deposits.
We present a map of Oxia Planum, Mars, the landing site for the ExoMars Rover. This shows surface texture and aeolian bedform distribution, classified using a deep learning (DL) system. A hierarchical classification scheme was developed, categorising the surface textures observed at the site. This was then used to train a DL network, the ‘Novelty or Anomaly Hunter – HiRISE’ (NOAH-H). The DL applied the classification scheme across a wider area than could have been mapped manually. The result showed strong agreement with human-mapped areas reserved for validation. The resulting product is presented in two ways, representing the two principle levels of the classification scheme. ‘Descriptive classes’ are purely textural in nature, making them compatible with a machine learning approach. These are then combined into ‘interpretive groups’, broader thematic classes, which provide an interpretation of the landscape. This step allows for a more intuitive analysis of the results by human users.
<p>Oxia Planum (OP), located at the transition between the ancient terrain of Arabia Terra and the low lying basin of Chryse Planitia, will be the landing site for the ESA-Roscosmos ExoMars Programme&#8217;s 2022 mission [1]. The descent module and landing platform, Kazachock, will transport the Rosalind Franklin Rover to search for signs of past and present life on Mars, and investigate the geochemical environment in the shallow subsurface over a 211-sol nominal mission.</p><p>OP forms a shallow basin, open to the north, characterized by clay-bearing bedrock, and episodic geological activity spans from the ~mid-Noachian to ~early Amazonian in age [2,3,4]. Building a thorough understanding of Oxia Planum prior to operations will provide testable hypotheses that facilitate interpretation of results, and hence provide an effective approach to address the mission&#8217;s science objectives. To this end, we have run a detailed group mapping campaign at HiRISE-scale using the Multi-Mission Geographic Information System (MMGIS) [5], co-registered HRSC [6], CaSSIS and HiRISE mosaics [7], and 116 1km<sup>2</sup> quads covering the 1-sigma landing ellipse envelope. Complementary CTX-scale mapping covers the wider area around the landing site and is described elsewhere [8].</p><p>Throughout 2020, 84 mapping volunteers associated with the mission&#8217;s Rover Science Operations Working Group followed a pre-formulated programme of training, familiarisation and mapping. With the mapping phase complete, a small sub-team are focused on map reconciliation phase, comprising data cleaning and science decision making. The process will culminate in map finalisation and submission for publication, and use in activities to plan rover science activities.</p><p>This campaign yields important advances for overall science readiness of the ExoMars 2022 mission:</p><ul><li>Team experience working, communicating and learning together, valuable for operations.</li> <li>Building team knowledge of the landing site, and the main scientific interpretations.</li> <li>Curated datasets and software available for team use in ongoing planning.</li> </ul><p>High-resolution map data representing our geologic understanding of Oxia Planum. This is an input to ongoing RSOWG work to construct the mission strategic plan, which provides science traceability from mission objectives to rover activities.</p><p><strong>Acknowledgments:</strong> We thank Fred Calef and Tariq Soliman at JPL for their support regarding MMGIS.</p><p><strong>References:</strong> [1] Vago, J. L. et al., (2017) Astrobiology 17 (6&#8211;7), 471&#8211;510. [2] Carter, J. et al., (2013) J. Geophys. Res. 118 (4), 831&#8211;858. [3] Quantin-Nataf, C. et al., (2021) Astrobiol. 21 (3),&#160; doi:10.1089/ast.2019.2191. [4] Fawdon P. et al., (2019) LPSC50 #2132. [5] Calef, F. J. et al., (2019) in 4th Planet. Data Work., Vol. 2151. [6] Gwinner, K. et al., (2016) Planet. Space Sci. 126, 93&#8211;138. [7] Volat, M. et al., (2020), EPSC, #564. [8] Hauber, E. et al. (2021), LPSC52.</p>
The geologic origin of the ancient, phyllosilicate-bearing bedrock at Oxia Planum, Mars, the ExoMars rover landing site, is unknown. The phyllosilicates record ancient aqueous processes, but the processes that formed the host bedrock remain elusive. Here, we use high-resolution orbital and topographic datasets from the HiRISE, CaSSIS and CTX instruments to investigate and characterize fluvial sinuous ridges (FSRs), found across the Oxia Planum region. The FSRs form segments up to 70 km long, are 20-600 m wide, and up to 9 m in height, with sub-horizontal layering common in ridge margins. Some FSRs comprise multi-story ridge systems; many are embedded within the phyllosilicate-bearing bedrock. We interpret the FSRs at Oxia Planum as deposits of ancient, episodically active, alluvial river systems (channel-belt and overbank deposits). Thus, at least some of the phyllosilicate-bearing bedrock was formed by ancient alluvial rivers, active across the wider region, though we do not exclude other processes from contributing to its formation as well. The presence of alluvial floodplains at Oxia Planum increases the chances of the ExoMars rover detecting signs of ancient life. Future exploration by the ExoMars rover can verify the alluvial interpretation and provides an opportunity to investigate some of the oldest river deposits in the Solar System.
Oxia Planum is the selected landing site for the ExoMars Rosalind Franklin (RF) Mission, launching in 2028. The science objectives of the mission are to search for signs of life and to characterize the geochemical environment in the subsurface as a function of depth. RF will accomplish this with its ‘Pasteur’ suite of scientific instruments, and a drilling and sampling subsystem to retrieve samples for analysis from as deep as 2 m [1].In preparation for this mission ESA, though the Rover Science Operations Working Group (RSOWG), has conducted a program of high resolution morphostratigraphic mapping and analysis to understand the geological significance of the landing site, to provide context for in-situ sample analysis and to serve as an input into strategic planning for rover operations. This effort: (i) has defined and described the geography of Oxia Planum as a framework for its exploration [2], (ii) has produced a geological map of the landing site [3], and (iii) in our ongoing work, is building a set of geological hypotheses that the RF rover can test during its nominal mission (in 2030-2031).Figure. 1: The (a) location and (b) context of Oxia Planum, inc. the availability of CaSSIS data which has been critical to developing our regional understanding. (c) The geological map of the Oxia Planum landing site summarizing the major unit groups (see Figure 2).Oxia Planum (Figure 1) preserves a record of the diverse geological process that formed and modified the landscape of western Arabia Terra throughout Mars’ geological history. Noachian Terrains contain extensive phyllosilicate–bearing materials in an environment of widespread aqueous alteration [4-7]. These deposits were subsequently added to (and modified by) fluvial activity and burial beneath regional layered terrain in the early Hesperian. They experienced further burial and erosion throughout the Amazonian [8-11]. Consequently, exploring the cross–section of strata exposed in Oxia Planum informs us about the paleoenvironmental conditions across a significant part of martian geological history (symbolized in Figure. 2). Furthermore, as Oxia is topographically open to the north, the processes recorded there probably reflect those occurring along the dichotomy boundary across the wider Chryse/Arabia region [4, 11- 15].We present: (1) The high-resolution geological map of the landing site in Oxia Planum [3] and the data used to create it [2]. (2) An overview of hypotheses relevant to key events in Oxia Planum's geological history. (3) A discussion of how future RF observations will impact these questions and our wider understanding of Mars.Figure 2: A summary of our current working hypotheses for the history of Oxia Planum visualized as an East to West schematic cross-section through the Oxia Basin. This connects the major geological units (Figure 1) to outstanding questions, the answer to which will tell us more about the overall geological evolution of Mars.Acknowledgments: We thank the CaSSIS and HiRISE teams for ongoing data collection in support of the RF rover mission. PF thanks UK Space Agency (ST/W002736/1) and the ExoMars Science Knowledge Program (SKP) for funding.References: [1] Vago et al. (2017) Astrobiology 17 (6–7), 471–510. [2] Fawdon, et al. (2021) J. Maps, 17:2, 621-637. [3] Fawdon et al. (2024) J. Maps 20(1). [4] Carter J. et al. (2015) Icarus 248, 373-382. [5] Quantin et al. (2021) Astrobiology 21:3, 345-366. [6] Mandon et al. (2021) Astrobiology 21:4, 464-480. [7] Brossier et al. (2022) Icarus 386. [8] McNeil et al. (2023) in LPSC 54 Abs.#1252. [9] Fawdon et al. (2022) JGR-Plan. 127, e2021JE007045. [10] Davis et al. (2023) EPSL 601, 117904. [11] Woodley et al. (2023) J. Maps, [12] Frueh et al. (2023) LPSC 54 Abs.#1440. [13] McNeil et al. 2022 JGR-Plan. 127, e2022JE007246. [14] Molina et al. (2017) Icarus 293 27-44. [15] Tornabene et al. (2023) LPSC 54 Abs.#2727
New developments in 3D visualisation software enable interrogation of volcanic architecture by analysis of surface morphology and composition. We apply this remote sensing approach using Geovisionary™ software to investigate volcano evolution in the Manda-Hararo rift segment, Afar, (Ethiopia) and compare this with the Syrtis Major volcanic complex on Mars.
In Afar, extensive exposure and low erosion rates in arid conditions allow comparison to Mars using remote sensing data sets of similar resolution. We use this comparison to understand the evolution of the Syrtis Major low-angle basaltic shield volcano – an edifice measuring 1500 km by 1000 km, formed in the early Hesperian (3.7 – 3.0 Ga). The complex is capped by calderas containing evolved volcanic products. Extensional fault systems and fissures, probably resulting from lack of buttressing on its ENE side, are aligned to the NNW-SSE these are comparable in morphology to the central part of Afar’s Manda-Hararo rift segment.
We present results of an initial field campaign at the Manda-Hararo rift segment and an initial survey of the Syrtis Major calderas. In Afar oblique views of lava flow surface morphologies and cross-sections through successive lava flows reveal details of the relationships between lavas, topography and local structure. Lobes range in scale from 0.1 m to 10 m wide and are typically 1.5 m thick. Most lavas in this rift segment are pāhoehoe, emplaced as inflating lobes. Cross-sectional surfaces, exposed in fault scarps, show interfingered lava flows. Some very recent low volume (< 0.5 km3) rubbly pāhoehoe lavas occur at the rift axis. Distinct ‘a’ā lava flows originating from Dabbahu volcano are faulted and interfingered with lavas from a rift axial source. MRO data has been interrogated for similar morphologies. We examine evidence of similarities in emplacement style and the interaction of lavas from both Syrtis Major calderas, using Geovisonary™.
Insights gained from the Manda-Hararo rift segment study will guide us in producing an architectural model of the evolution of the Syrtis Major complex, with the aid of further high resolution Mars imaging, including newly requested data from the Mars Reconnaissance Orbiter spacecraft.
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