DOCSLIB.ORG

Characterization of Laterally Contiguous

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Characterization of Laterally Contiguous CHARACTERIZATION OF LATERALLY CONTIGUOUS PHYLLOSILICATE DEPOSITS IN WEST MARGARITIFER TERRA, MARS 3rd Planetary Data Workshop and Planetary Geologic Mappers Meeting June 12-15, 2017 K. D. Seelos, R. E. Maxwell, F. P. Seelos, D. L. Buczkowski, C. E. Viviano-Beck Regional Pedogenesis? Mawrth Fig. 16, McKeown et al. 2009 MargaritiferRegional stratigraphiesBasin: : Fe/MgAl phyllosilicates phyllosilicates over with darkFe/Mg capping phyllosilicates material with dark capping material Mawrth Fig. 9, Noe Dobrea et al, 2010 Margaritifer Basin Valles Marineris / Noachis From Fig. 14, Salvatore et al. 2016 Fig. 16, Le Deit et al. 2012 West Margaritifer . ShallowA complex Fe/Mg phyllosilicategeologic history: deposits: Remnants of ancient impacts Widespread (Ladon) Variety of Noachian valley elevationsnetworks and Exposedchannels at the surface,Hesperian in fractureoutflow walls, bychannels impacts and chaos terrain Spectrallyformation consistent 3 Types of Exposures . Crater Walls & Ejecta . Chaos/Fracture Walls . Intercrater (Surface) . Outcrops above identified in CRISM data (Certain and Less Certain) . Note: Outcrops are not found within chaos terrains, mountainous terrain (e.g., Ladon Montes) Intercrater & Crater Exposures 9 Datasets: CRISM – Mapping (180 m/pix, multispectral map tiles) – Targeted (20 m/pix, hyperspectral MTRDRs) THEMIS (100 m/pix, controlled mosaics) – Daytime IR – Qual. thermal inertia next MOLA (460 m/pix) slide HRSC (50-175 m/pix) CTX (6 m/pix) HiRISE – Red and color (≥ 25 cm/pix) PFM browse – DTMs and orthos Thin, low albedo overburden obscures CRISM and moderates thermal inertia signatures. ESP_018662_1750_COLOR 200 m Intercrater Exposure CTX light-toned morphology + THEMIS elevated thermal inertia allows units to be extended beyond/between CRISM observations. PFM browse Crater & Escarpment Exposures next Phyllosilicate slide layer likely exposed along all of these scarps… PFM browse 200 m ESP_021853_1780_COLOR 9 ESP_021853_1780_COLOR 200 m Inferred MOLA topography, 100 m contours THEMIS qualitative TI over CTX Units . “Extended” and “Buried” units necessitate spatially coherent THEMIS TI and CRISM data anchors CRISM D2300 over CTX Phyllosilicate Units over CTX Extended unit connects surficial exposures Buried map unit connects impact- excavated exposures Continuum Removed CRISM Spectral Nontronite Library Spectra Characteristics Saponite 2.304 µm Reflectance Mg . Examined 138 CRISM Map- Projected Targeted Reduced Fe Data Records (MTRDRs) . Light-toned layer is dominated by Mg-smectite (e.g., saponite) . Little to no variability across region . Absorptions at 1.41, 1.92, Mg smectite . No discernable vertical 2.304, variation Fe smectite sometimes No indication of Al- for Ratio CRISM (offset clarity) phyllosilicates CRISM Reference Spectra 2.39 µm (Viviano-Beck et al., 2014) Formation Mechanism(s) A multiple-process EXPECTED OBSERVATIONS: emplacement Fluviolacustrine: Burial/ Diagenesis: Pedogenesis: Hydrothermal: Minerals fall from suspension or Interaction of water table with Alteration due to rain Alteration of precursor scenario? precipitate directly in low energy buried precursor material results water percolation and material caused by aqueous settings. in zone of alteration. leaching of precursor heating of subsurface 1. Initial air fall deposition CHARACTERISTIC material. water. Alteration zone corresponds to Conforms to surface Topography/ Horizontal deposition in basins or 2. Reworked by water table depth – follows topography at time of Variable low areas adjacent to channels aeolian/aqueous elevation - topography X formation X processes, settles into Limited to extent of basin or Spatial distribution Extensive Extensive Localized to heat source local topographic lows flooded areasX* X Variable; thicker in basin center Layer thickness Little variation Little variation Variable 3a. Capped/preserved by or local lows ? ?+ ?+ X Depends on heat source subsequent volcanic May or may not be preserved in Fine to massive; planes are and precursor material; deposits precursor material; compaction Not preserved Bedding horizontal, subparallel may or may not be may produce layering X - 3b. Aqueously altered, either preserved through surficial or Deltas, distributary systems, Mineralized veins, concretions Dendritic channel Associated inlet/outlet channels, fluvial Volcanoes or volcanic groundwater interaction (may not be observed using systems may or may not channels, erosional scours or deposits, impact craters morphologies ?+ remote sensing)?+ be preserved?- 4. Exposed/eroded by channel bars, mudcracks X fluvial activity and chaos Unconformable; drapes pre- Gradational lower Stratigraphic Alteration zone could intersect Cross-cuts preexisting formation existing topography; may embay contact, sharp upper pre-existing stratigraphyX terrains X relationships high-standing areas contact Depends on precursor material Sequence of more- Higher-temp. smectites, Smectites, evaporates, sulfates, Mineralogy and water chemistry: hydrated altered (kaolinites) to kaolinites, hydrated carbonates silica, smectites, zeolites, illite, less-alteredX* (smectites) silica, jarositeX, prehnite, kaolinites, chlorite, prehnite with depth chlorite, serpentine Mineralogy With distance from basin center Diverse and variable with or within local lows (possible Regionally consistent Regionally consistent distance from heat variation “bath tub ring” effect)X source X *not a deal breaker Summary .. Ongoing/Last(?)WestConstrained Margaritifer to be stepshosts Noachian an - extensiveaged Measure layer layer of thickness Fe/Mg to smectite assessEmbays-bearing regional Early Noachian material trends CompareSurfacialhighstanding, tochaos/fracture similarterrain nearby walls, phyllosilicateimpactPartially-exhumed exposed units and Large,probably– Valles contiguous reworkedMarineris walls/plainsoutcrops by at varietyNoachian– Northwest of elevations“overland” Noachis Terrachannels FewCrosscut 10s of by meters reactivated thick, internalHesperian layering, outflow capped channels by dark,and chaos basaltic terrain material fractures Regionally consistent spectral characteristics .
Load more

Recommended publications
  • Endogenic and Exogenic Contributions to Visible-Wavelength Spectra of Europa’S Trailing Hemisphere
    Preprint typeset using LATEX style AASTeX6 v. 1.0 ENDOGENIC AND EXOGENIC CONTRIBUTIONS TO VISIBLE-WAVELENGTH SPECTRA OF EUROPA'S TRAILING HEMISPHERE Samantha K. Trumbo, Michael E. Brown Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA Kevin P. Hand Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA ABSTRACT The composition of Europa's trailing hemisphere reflects the combined influences of endogenous geo- logic resurfacing and exogenous sulfur radiolysis. Using spatially resolved visible-wavelength spectra of Europa obtained with the Hubble Space Telescope, we map multiple spectral features across the trailing hemisphere and compare their geographies with the distributions of large-scale geology, mag- netospheric bombardment, and surface color. Based on such comparisons, we interpret some aspects of our spectra as indicative of purely exogenous sulfur radiolysis products and other aspects as in- dicative of radiolysis products formed from a mixture of endogenous material and magnetospheric sulfur. The spatial distributions of two of the absorptions seen in our spectra|a widespread down- turn toward the near-UV and a distinct feature at 530 nm|appear consistent with sulfur allotropes previously suggested from ground-based spectrophotometry. However, the geographies of two addi- tional features|an absorption feature at 360 nm and the spectral slope at red wavelengths|are more consistent with endogenous material that has been altered by sulfur radiolysis. We suggest irradiated sulfate salts as potential candidates for this material, but we are unable to identify particular species with the available data. Keywords: planets and satellites: composition | planets and satellites: individual (Europa) | planets and satellites: surfaces 1.
    [Show full text]
  • Schmidt Et Al
    Earth and Planetary Science Letters 384 (2013) 37–41 Contents lists available at ScienceDirect Earth and Planetary Science Letters www.elsevier.com/locate/epsl Detectability of thermal signatures associated with active formation of ‘chaos terrain’ on Europa ∗ Oleg Abramov a, , Julie A. Rathbun b, Britney E. Schmidt c,JohnR.Spencerd a U.S. Geological Survey, Astrogeology Science Center, 2255 N. Gemini Dr., Flagstaff, AZ 86001, USA b Planetary Science Institute, 1700 E. Fort Lowell Rd., Suite 106, Tucson, AZ 85719-2395, USA c Georgia Institute of Technology, School of Earth and Atmospheric Sciences, 311 Ferst Dr., Atlanta, GA 30312, USA d Southwest Research Institute, 1050 Walnut St., Suite 300, Boulder, CO 80302, USA article info abstract Article history: A recent study by Schmidt et al. (2011) suggests that Thera Macula, one of the “chaos regions” on Europa, Received 21 February 2013 may be actively forming over a large liquid water lens. Such a process could conceivably produce a Received in revised form 12 September thermal anomaly detectable by a future Europa orbiter or flyby mission, allowing for a direct verification 2013 of this finding. Here, we present a set of models that quantitatively assess the surface and subsurface Accepted 20 September 2013 temperatures associated with an actively resurfacing chaos region using constraints from Thera Macula. Available online 26 October 2013 Editor: C. Sotin The results of this numerical study suggest that the surface temperature over an active chaos region can be as high as ∼200 K. However, low-resolution Galileo Photo-Polarimeter Radiometer (PPR) observations Keywords: indicate temperatures below 120 K over Thera Macula.
    [Show full text]
  • Rapid Single Image-Based DTM Estimation from Exomars TGO Cassis Images Using Generative Adversarial U-Nets
    remote sensing Article Rapid Single Image-Based DTM Estimation from ExoMars TGO CaSSIS Images Using Generative Adversarial U-Nets Yu Tao 1,* , Siting Xiong 2, Susan J. Conway 3, Jan-Peter Muller 1 , Anthony Guimpier 3, Peter Fawdon 4, Nicolas Thomas 5 and Gabriele Cremonese 6 1 Mullard Space Science Laboratory, Imaging Group, Department of Space and Climate Physics, University College London, Holmbury St Mary, Surrey RH5 6NT, UK; [email protected] 2 College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China; [email protected] 3 Laboratoire de Planétologie et Géodynamique, CNRS, UMR 6112, Universités de Nantes, 44300 Nantes, France; [email protected] (S.J.C.); [email protected] (A.G.) 4 School of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA, UK; [email protected] 5 Physikalisches Institut, Universität Bern, Sidlerstrasse 5, 3012 Bern, Switzerland; [email protected] 6 INAF, Osservatorio Astronomico di Padova, 35122 Padova, Italy; [email protected] * Correspondence: [email protected] Abstract: The lack of adequate stereo coverage and where available, lengthy processing time, various artefacts, and unsatisfactory quality and complexity of automating the selection of the best set of processing parameters, have long been big barriers for large-area planetary 3D mapping. In this paper, Citation: Tao, Y.; Xiong, S.; Conway, we propose a deep learning-based solution, called MADNet (Multi-scale generative Adversarial S.J.; Muller, J.-P.; Guimpier, A.; u-net with Dense convolutional and up-projection blocks), that avoids or resolves all of the above Fawdon, P.; Thomas, N.; Cremonese, G.
    [Show full text]
  • Paleoflooding in the Solar System: Comparison Among Mechanisms For
    Paleoflooding in the Solar System: comparison among mechanisms for flood generation on Earth, Mars, and Titan Devon Burr Earth and Planetary Sciences Department EPS 306 University of Tennessee Knoxville 1412 Circle Dr. Knoxville TN 39776-1410 USA [email protected] ABSTRACT Conditions allow surficial liquid flow on three bodies in the Solar System, Earth, Mars, and Titan. Evidence for surficial liquid flood flow has been observed on Earth and Mars. The mechanisms for generating flood flow vary according to the surficial conditions on each body. The most common flood-generating mechanism on Earth is wide-spread glaciation, which requires an atmospheric cycle of a volatile that can assume the solid phase. Volcanism is also a prevalent cause for terrestrial flooding, which other mechanisms producing smaller, though more frequent, floods. On Mars, the mechanism for flood generation has changed over the planet’s history. Surface storage of floodwater early in Mars’ history gave way to subsurface storage as Mars’ climate deteriorated. As on Earth, Mars’ flooding is an effect of the ability of the operative volatile to assume the solid phase, although on Mars, this has occurred in the subsurface. According to this paradigm, Titan conditions preclude extreme flooding because the operative volatile, which is methane, cannot assume the solid phase. Mechanisms that produce smaller but more frequent floods on Earth, namely extreme precipitation events, are likely the most important flood generators on Titan. 1. Introduction The historical flow of paleoflood science has risen and fallen largely in concert with prevailing scientific paradigms (Baker 1998). The paradigm in the 17 th century was catastrophism, the idea that geology is the product of sudden, short, violent events.
    [Show full text]
  • Active Formation of 'Chaos Terrain' Over Shallow Subsurface Water on Europa
    LETTER doi:10.1038/nature10608 Active formation of ‘chaos terrain’ over shallow subsurface water on Europa B. E. Schmidt1, D. D. Blankenship1, G. W. Patterson2 & P. M. Schenk3 Europa, the innermost icy satellite of Jupiter, has a tortured young topography differs. Conamara Chaos is raised and contains raised surface1–4 and sustains a liquid water ocean1–6 below an ice shell of matrix ‘domes’. Thera Macula, however, is sunken below the sur- highly debated thickness1–5,7–10. Quasi-circular areas of ice disrup- rounding surface. These observations, informed by the environments tion called chaos terrains are unique to Europa, and both their on Earth described above, suggest a four-phase ‘lens-collapse model’ formation and the ice-shell thickness depend on Europa’s thermal for chaos terrain formation (Fig. 3). (1) Ascending thermal plumes of state1–5,7–17. No model so far has been able to explain why features relatively pure ice13 cross the eutectic point of overlying impure ice, such as Conamara Chaos stand above surrounding terrain and producing surface deflection in response to volume change associated contain matrix domes10,18. Melt-through of a thin (few-kilometre) with pressure melting of the ice (Fig. 3a). (2) Resulting hydraulic shell3,7,8 is thermodynamically improbable and cannot raise the gradients and driving forces produce a sealed, pressurized melt lens ice10,18. The buoyancy of material rising as either plumes of warm, (Fig. 3b). (3) Extension of the sinking brittle ice ‘lid’ over the lens pure ice called diapirs1,9–15 or convective cells16,17 in a thick (.10 ultimately generates deep fractures from below, allowing brine to both kilometres) shell is insufficient to produce the observed chaos be injected into and percolate through overlying ice, forming a fluidized heights, and no single plume can create matrix domes10,18.
    [Show full text]
  • Geomorphic Investigations of Martian Chaos Terrain
    Lunar and Planetary Science XLVIII (2017) 1121.pdf MAKING SENSE OF CHAOS: GEOMORPHIC INVESTIGATIONS OF MARTIAN CHAOS TERRAIN. J.H. Gearon1, J.S. Levy1, and T.A. Goudge2, 1University of Texas Institute for Geophysics, Austin, TX, 78758. [email protected], [email protected], 2Jackson School of Geosciences, Austin, TX. Introduction. Chaos terrain (or simply, chaos) is [5-8], with gap-filling topography provided by MOLA a widely-studied, but still poorly understood global ge- gridded data [9]. Outlines of coherent mesa features as omorphic unit on Mars. Chaos terrain is characterized well as outlines of eroded massifs features were mapped by the presence of polygonally-shaped mesas and mas- (Fig. 1) and morphometric and topographic geostatistics sifs, separated by deep canyons that form a polygonal were extracted from these polygons. Measurements in- “jigsaw pattern” [1]. Chaos terrain is globally distrib- cluded: cell area, cell distance from centroid, mean mesa uted, but is concentrated in the Tharsis/Valles Marineris slope, and “missing volume” (the difference in volume region of Mars [2]. Chaos is spatially associated with between a 3D surface fitted to chaos mesa and massif outflow channels and is widely held to be related to out- cell tops and the measured topography) (Fig. 2). flow channel formation mechanisms (e.g., fracture of Calculations were also made of chaos fractured unit vol- the surface and release of groundwater) [2-4]. ume by fitting a lower surface to the chaos inter-mesa Accordingly, three major hypotheses for the for- trough network, and differencing the upper surface (in- mation of chaos terrain exist: 1) subsidence/collapse as- terpolated between mesa high points) from the lower sociated with breaching of the martian cryosphere and surface.
    [Show full text]
  • Identifying Evidence for Explosive Volcanism on Mars Through Geomorphologic and Thermophysical Observations
    IDENTIFYING EVIDENCE FOR EXPLOSIVE VOLCANISM ON MARS THROUGH GEOMORPHOLOGIC AND THERMOPHYSICAL OBSERVATIONS by Gabriel Cecilio Garcia A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Geosciences Boise State University May 2018 © 2018 Gabriel Cecilio Garcia ALL RIGHTS RESERVED BOISE STATE UNIVERSITY GRADUATE COLLEGE DEFENSE COMMITTEE AND FINAL READING APPROVALS of the thesis submitted by Gabriel Cecilio Garcia Thesis Title: Identifying Evidence for Explosive Volcanism on Mars through Geomorphologic and Thermophysical Observations Date of Final Oral Examination: 24 January 2018 The following individuals read and discussed the thesis submitted by student Gabriel Cecilio Garcia, and they evaluated his presentation and response to questions during the final oral examination. They found that the student passed the final oral examination. Brittany D. Brand, Ph.D. Chair, Supervisory Committee Joshua L. Bandfield, Ph.D. Member, Supervisory Committee Jennifer L. Pierce, Ph.D. Member, Supervisory Committee The final reading approval of the thesis was granted by Brittany D. Brand, Ph.D., Chair of the Supervisory Committee. The thesis was approved by the Graduate College. DEDICATION I dedicate this thesis to my parents. Their love and support has provided me the opportunity to strive for greatness and live a life that I can truly be proud of. No matter where I go, I will always live by your example. iv ACKNOWLEDGEMENTS I would like to thank my advisors, Brittany Brand and Joshua Bandfield, for all they have helped me with. I would not be the scientist I am now without their guidance and teachings. I would also like to thank the Idaho Space Grant Consortium for funding this research.
    [Show full text]
  • Seismology of Icy Ocean Worlds
    ASTROBIOLOGY Volume 18, Number 1, 2018 ª Mary Ann Liebert, Inc. DOI: 10.1089/ast.2016.1612 Vital Signs: Seismology of Icy Ocean Worlds Steven D. Vance,1 Sharon Kedar,1 Mark P. Panning,1 Simon C. Sta¨hler,2,3 Bruce G. Bills,1 Ralph D. Lorenz,4 Hsin-Hua Huang,5,6 W.T. Pike,7 Julie C. Castillo,1 Philippe Lognonne´,8 Victor C. Tsai,6 and Alyssa R. Rhoden9 Abstract Ice-covered ocean worlds possess diverse energy sources and associated mechanisms that are capable of driving significant seismic activity, but to date no measurements of their seismic activity have been obtained. Such investigations could reveal the transport properties and radial structures, with possibilities for locating and characterizing trapped liquids that may host life and yielding critical constraints on redox fluxes and thus on habitability. Modeling efforts have examined seismic sources from tectonic fracturing and impacts. Here, we describe other possible seismic sources, their associations with science questions constraining habitability, and the feasibility of implementing such investigations. We argue, by analogy with the Moon, that detectable seismic activity should occur frequently on tidally flexed ocean worlds. Their ices fracture more easily than rocks and dissipate more tidal energy than the <1 GW of the Moon and Mars. Icy ocean worlds also should create less thermal noise due to their greater distance and consequently smaller diurnal temperature variations. They also lack substantial atmospheres (except in the case of Titan) that would create additional noise. Thus, seismic experiments could be less complex and less susceptible to noise than prior or planned planetary seismology investigations of the Moon or Mars.
    [Show full text]
  • Characterizing Geomorphic and Mineralogical Features in the Eridania Basin and Their Implications for the Geologic History of Mars
    52nd Lunar and Planetary Science Conference 2021 (LPI Contrib. No. 2548) 1269.pdf CHARACTERIZING GEOMORPHIC AND MINERALOGICAL FEATURES IN THE ERIDANIA BASIN AND THEIR IMPLICATIONS FOR THE GEOLOGIC HISTORY OF MARS. D. E. Chapline1 and M. R. Salvatore2, 1Department of Geology, Pomona College, Claremont, CA, [email protected]. 2Department of Astronomy and Planetary Science, Northern Arizona University. Introduction: The Eridania basin on Mars is a Spectrometer for Mars (CRISM [7]). Daytime and network of highly degraded impact basins that covers nighttime infrared mosaics from the Thermal Emission more than one million Km2 [1] (Fig. 1). It is believed that Imaging System (THEMIS [8]) instrument were used to water from the Eridania basin carved Ma’adim Vallis, differentiate between different surface units. High- one of the longest outflow channels on the Martian resolution visible images from the Context Camera (CTX surface, in a single overflow event [1]. Ergo, the basin [9]) and the High-Resolution Imaging Science holds great importance for understanding the Experiment (HiRISE [10]) were utilized to provide hydrological and fluvial history of the planet. Despite context for different spectral and thermophysical units, as being heavily modified by subsequent geologic well as to identify different geologic formations. processes, evidence of Eridania’s lacustrine origin is still Topographic data used in this study were derived from prominent in the area, suggesting a long history of the blended Mars Orbiter Laser Altimeter (MOLA [11]) modification by water. and High-Resolution Stereo Camera (HRSC [12]) Previous research has helped to characterize the instruments. Where necessary, raw data were acquired basin’s stratigraphy and mineralogy [2-5].
    [Show full text]
  • Mineralogy, Structure and Morphology of Western Eos Chaos Trough of Valles Marineris, Mars Asif Iqbal Kakkassery and Rajesh V
    Mineralogy, Structure and Morphology of Western Eos Chaos Trough of Valles Marineris, Mars Asif Iqbal Kakkassery and Rajesh V. J. Indian Institute of Space Science and Technology, Trivandrum, India 20th National Space Sciences Symposium (NSSS-2019) INTRODUCTION a DATA SETS AND Chaotic terrains of Mars are enclosed and semi-enclosed METHODS deep seated region composed of knobs, rock masses of Mars Colour Camera (MCC) onboard ISRO’s different sizes and elevated, irregular and flat-topped Mars Orbiter Mission (MOM1), Context Camera mounts which are often marked out as mesas with steep (CTX), High Resolution Imaging Science slopes (Rodriguez et al., 2005a; Meresse et al., 2008; Experiment (HiRISE) and Compact Warner et al., 2011). Reconnaissance Imaging Spectrometer for Mars Majority of the chaotic terrains lie near to the Martian (CRISM) aboard NASA’s MRO mission. equator or dichotomy boundary (Figure 1a). And the Eos chaos (Figure 1b) is an equatorial chaotic terrain, located on the East of Valles Marineris (with central coordinates b ~16°49'12.00"S and ~46° 7'12.00"W). RESEARCH PROBLEM To investigate the geological processes which significantly influenced the formation and evolution of the near circular western Eos Chaos trough.(Figure 2) Figure 1:(a)Topographic image of Martian surface prepared from Mars Orbital Laser Altimeter (MOLA) of the Mars Global Surveyor (MGS). The study area Valles Marineris is marked within the image. Major chaotic terrains are shown as red points. (b) Major Tectonic features in Figure 2:Eos Chaos terrain represented in Mars Colour Camera (MCC) and around Valles Marineris are shown in a mosaic of MCC-Viking Figure 3:Workflow diagram explaining the methodology image of Valles Marineris area.
    [Show full text]
  • POSSIBLE VOLCANIC AVALANCHE DEPOSIT NORTH of GALE CRATER Introduction We Investigate an Unnamed Landform (“North Gale Landform”; Fig
    POSSIBLE VOLCANIC AVALANCHE DEPOSIT NORTH OF GALE CRATER Introduction We investigate an unnamed landform (“North Gale landform”; Fig. 1, 3) located to the north of 1 1 2 1 2 1 1 1 Gale Crater that may represent a source for volcaniclastic sediments identified by the Mars Science J.J.C. Churchill , M.E. Schmidt , J.A. Berger , F. Fueten , L.L. Tornabene , L.E. Vargas and J. Walmsley Dept. Earth Sci, Laboratory rover, Curiosity [1]. We further propose that the landform may a) be volcanic in origin, 2 and b) have produced a massive landslide. The North Gale landform is arcuate and quasi circular BrockUniversity, St. Catharines, ON, Canada L2S 3A1, Dept. Earth Sci, Univ. Western On, London, ON, Canada, landform with a 40.6 km diameter and a maximum relief of 3.2 km above the surrounding terrain. It features a large amphitheater (25 km) that opens to the southeast with dissected surface morpholo- N6A 5B7, [email protected] gy. The landform is surrounded by steep talus slopes (28-34°). Degraded Impact Crater? The North Gale landform lacks key characteristics of impact craters. A B 1. The feature sits above the base level of the surrounding topography (Fig. 3, Fig. 4). Methods Impact craters may have elevated rims, but the crater itself usually sits lower than the • High resolution images from Mars Reconnaissance Orbiter’s (MRO) Context Camera surrounding topography. Exceptions are the pedestal, perched and excess ejecta craters (CTX) datasets [3] were used to identify morphologic features, structures and units related which may exist above the current terrain [8].
    [Show full text]
  • Possible Volcanic Avalanche Deposit North of Gale Crater
    Lunar and Planetary Science XLVIII (2017) 2411.pdf POSSIBLE VOLCANIC AVALANCHE DEPOSIT NORTH OF GALE CRATER. J.J.C. Churchill1, M.E. Schmidt1, J.A. Berger2, F. Fueten1, L.L. Tornabene2, L.E. Vargas1 and J. Walmsley1 1Dept. Earth Sci, Brock University, St. Catharines, ON, Canada L2S 3A1, 2Dept. Earth Sci, Univ. Western On, London, ON, Canada, N6A 5B7, [email protected] Introduction: Volcaniclastic sediments have been identified in Gale Crater by the Mars Science Labora- tory rover, Curiosity [1]. These sediments likely derive from the Gale Crater rim and Peace Vallis catchment [2]. Here we describe an unnamed landform (“North Gale landform”; Fig. 1) located to the north of Gale Crater and outside the present-day catchment that may represent a possible source feature for some of these sediments. We further propose that the landform may be volcanic in origin, . Methods: High resolution images from Mars Re- connaissance Orbiter’s (MRO) Context Camera (CTX) datasets [3] were used to identify morphologic features, structures and units related to the North Gale landform. CTX digtal elevation models (DEM) [3] and High Res- olution Stereo Camera (HRSC, Mars Express) DEMs [4] were used to extract elevation profiles of the land- form. Mars Orbital Laser Altimeter (MOLA, Mars Global Surveyor) [5] MEGDR elevation data was used for finding regional elevation (Fig. 1) as well as for Fig. 1: Regional map surrounding North Gale landform. Inset shows a likely debris flow on North Gale landform’s north side. CTX [3] identifying craters in the region (Fig. 2). Terrestrial vol- images with MOLA [5] elevation data overlaid.
    [Show full text]