DOCSLIB.ORG

The Bosumtwi Impact Crater, a Terrestrial Rampart Crater

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Bosumtwi Impact Crater, a Terrestrial Rampart Crater Lunar and Planetary Science XLVIII (2017) 2583.pdf THE BOSUMTWI IMPACT CRATER, A TERRESTRIAL RAMPART CRATER. G. Wulf1 and T. Kenkmann1, 1Institute of Earth and Environmental Sciences -Geology-, Albert-Ludwigs-University Freiburg, Ger- many, [email protected]. Introduction: The Bosumtwi impact crater in resolution of 1 arc-second (~30 m at the equator) were Ghana (06°30`N, 01°25`W) is one of the youngest and used as base data to derive catchment areas and drain- best preserved terrestrial impact craters [1, 2]. The age networks in the surrounding of Bosumtwi crater 1.07 Ma old impact structure has a pronounced crater (Fig. 1a). For morphometric comparisons, we deter- rim with a diameter of 10.5 km [3]. The circular struc- mined the mean elevation of the topography at defined ture is somewhat distorted in the SE sector by the radial distances from crater center (bins of 200 m) in northern flank of the NE–SW trending Obuom Moun- order to construct an averaged radial elevation profile tain Range [4] (Fig. 1a). The impact structure forms a (Fig. 1b). In the process, the southern margin was hydrologically closed basin that is almost completely cropped and not incorporated into the analysis because filled by the 8.5 km diameter Lake Bosumtwi. The this area is strongly affected by the northern flank of impact crater was intensely studied in the framework the NE–SW trending Obuom Mountain Range (Fig of various drillings campaigns, e.g., the International 1a). Continental Scientific Drilling Program (ICDP) drill- ing in 2004 [5, 6]. Suevites (polymict, glass-bearing breccias) and polymict clastic impact breccias were found in the boreholes as well as in the northern and southern parts within the crater structure. Although chemical weathering is intense in the tropical rain for- est environment and led to the formation of locally thick lateritic soils, a lot of breccias associated with the formation of the crater are still preserved outside of the crater rim (see review by [2]). Moreover, polymict and monomict clastic breccias were reported from numer- ous places around the impact crater whose impact origin was not unambiguously confirmed [2]. A strik- ing feature of the Bosumtwi impact structure is a shal- low, near-circular, depression at 7-8.5 km from the crater center directly beyond the crater rim, followed by a shallow outer topographic ring feature at 18-20 Fig.1: SRTM elevation data and derived averaged radial km radial distance from the impact center [7, 8] (Fig. elevation profile of Bosumtwi crater (A/B) show a circular 1b). This feature is visible in radar satellite images as depression followed by an elevated ring beyond the crater well as in aero-radiometry data, indicating lithological rim of Bosumtwi crater; CTX DTM and derived averaged as well as topographic control [4, 8, 9]. It was suggest- radial elevation profile of the Martian DLE crater Steinheim ed that preferential removal of ejecta within the area (C/D) [data from 11] show similar results including moat and just outside of the crater rim could be the reason for rampart. this shallow depression [8] or original depositional patterns as well as impact-induced concentric fractur- In addition, we used the principal component anal- ing could also be involved [4]. ysis (PCA) on the base of Landsat and ASTER data to Here we present preliminary results showing that emphasize variations in the multispectral data and thus the morphological features (circular depression and bring out strong patterns in the dataset (Fig. 2b). In topographical ring) beyond the crater rim of the further steps, we compared the results with a Martian Bosumtwi crater are the remnants of an ejecta rampart rampart crater of similar size. The Martian crater and thus, that the Bosumtwi crater is a rampart crater. Steinheim (190.65°E 54.57°N)[11] is a young 11.2 km Methods: The Bosumtwi crater in Ghana was ana- diameter double-layered ejecta (DLE) crater in Arca- lyzed in detail on the base of remote sensing data. A dia Planitia and has an excellent coverage of high- GIS environment was implemented for geospatial resolution image data. We used the Ames Stereo Pipe- analyses of digital elevation models (DEMs) and mul- line to build a high-resolution digital elevation model tispectral analyses. Digital elevation data from the (DEM) based upon CTX imagery and MOLA (Mars Shuttle Radar Topography Mission (SRTM) with a Lunar and Planetary Science XLVIII (2017) 2583.pdf Orbiter Laser Altimeter) data for further detailed anal- multispectral data of this area provide no clear signa- yses of the ejecta morphology of Steinheim crater [10], ture for possible ejecta deposits due to the dense rain- including a radial elevation profile and the determina- forest cover, a weak halo-like signal surrounds the tion of a hypothetic drainage pattern and catchment impact crater possibly indicating a similar composition areas (Fig. 1c, d). of the moat and rampart area (Fig. 2b). Following this approach, it is conspicuous that the drainage network around Bosumtwi crater is showing a circular pattern in the slightly depressed annular zone (Fig. 3a). As- suming Bosumtwi crater as the result of a lunar like impact event, the thickness of the ejecta blanket would decrease with increasing radial distance to crater center as the result of ballistic sedimentation and erosion. Under such circumstances, a radial drainage pattern would be expected in contrast to the actual concentric pattern. As a thought experiment, we have generated a hypothetical drainage network for the Martian DLE Fig.2: A) Mapped breccias in the surrounding of Bosumtwi crater Steinheim. Interestingly, the drainage pattern of crater (data from [2]: red = suevites (polymict, glass-bearing Steinheim crater shows a lot of similarities to breccias); white circles = polymict clastic impact breccias; Bosumtwi including a local watershed along the crest- white triangles = polymict clastic breccias (genetically un- line of the rampart and a concentric discharge pattern classified, likely impact-related); black circles = polymict in the moat area (Fig. 3b). and monomict clastic breccias (unspecified, possibly impact- Conclusions and Outlook: The morphological related). B) False colour RGB image of the Principal com- features (circular depression and topographical ring) ponent analysis (PCA) on the base of ASTER VNIR data. beyond the crater rim of Bosumtwi crater as well as the ejecta distribution and drainage pattern show many similarities to Martian rampart craters. Therefore, we suggest that Bosumtwi crater shows the eroded rem- nants of an ejecta rampart, possibly similar to the Ries crater in Germany [12], and thus, is a terrestrial ram- part crater. In future works, this assumption will be proven in more detail by using TanDEM-X imagery of higher resolution and further multispectral data anal- yses. References: [1] Scholz, A.C. et al. (2002) Geology, vol. 30, pp. 939–942. [2] Koeberl, C. and Reimold, W.U. Fig.3: Derived drainage pattern and accordant catchment (2005) Jahrbuch der Geologischen Bundesanstalt, vol. 145, areas for Bosumtwi crater (A) and the Martian Steinheim pp. 31–70. [3] Koeberl, C. et al. (1997) Geochim. crater (B). Cosmochim. Acta, vol. 61, pp. 1745–1772. [4] Reimold, W.U. and Koeberl, C. (2014) Journal of African Earth Sci- Results and Discussion: The SRTM elevation da- ences, vol. 93, pp. 57-175. [5] Turner, B.F. et al. (1996) ta and the derived averaged radial elevation profile Limnol. Oceanogr., vol. 41, pp. 1415–1424. [6] Koeberl, C. show a circular depression followed by an elevated et al. (2007) Meteoritics & Planetary Science, vol. 42, pp. ring beyond the crater rim of Bosumtwi crater (Fig. 1a, 477–896. [7] Jones, W.B. et al. (1981) Ghana. Geol. Soc. b). The morphological characteristics of this topo- Am. Bull., vol. 92, pp. 342–349. [8] Wagner, R. et al. (2002) graphic pattern show striking similarities with regard In Meteorite Impacts in Precambrian Shields. Impact Stu- to position, dimension, and shape to those of Martian dies, vol. 2: Plado, J., Pesonen, L.J. (Eds.), Springer, Berlin, DLE craters, which typically possess depressions Heidelberg, pp. 189–210. [9] Pesonen, L.J. et al (2003) (called moats) and subsequent broad, elevated ridges Yearbook of the Austrian Geological Survey, Vienna, vol. (called ramparts) [11] (Fig. 1c, d). In the case of Mar- 143, pp. 581–604. [10] Moratto Z.M. et al. (2010) 41st Lunar tian craters, this morphological trend is due to the dis- and Planetary Science Conference, abstract #2364. [11] tribution of the ejecta blanket. Indeed, Bosumtwi also Wulf G. and Kenkmann T. (2015). Meteoritics & Planetary shows a lot of evidence for ejecta deposits within this Science, vol. 50, pp. 173–203. [12] Sturm S. et al. (2013) area including a multitude of impact-related and possi- Geology, vol. 41(5), pp. 531-534. bly impact-related breccias (Fig. 2a). Although the .
Load more

Recommended publications
  • Martian Subsurface Properties and Crater Formation Processes Inferred from Fresh Impact Crater Geometries
    Martian Subsurface Properties and Crater Formation Processes Inferred From Fresh Impact Crater Geometries The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Stewart, Sarah T., and Gregory J. Valiant. 2006. Martian subsurface properties and crater formation processes inferred from fresh impact crater geometries. Meteoritics and Planetary Sciences 41: 1509-1537. Published Version http://meteoritics.org/ Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:4727301 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA Meteoritics & Planetary Science 41, Nr 10, 1509–1537 (2006) Abstract available online at http://meteoritics.org Martian subsurface properties and crater formation processes inferred from fresh impact crater geometries Sarah T. STEWART* and Gregory J. VALIANT Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, Massachusetts 02138, USA *Corresponding author. E-mail: [email protected] (Received 22 October 2005; revision accepted 30 June 2006) Abstract–The geometry of simple impact craters reflects the properties of the target materials, and the diverse range of fluidized morphologies observed in Martian ejecta blankets are controlled by the near-surface composition and the climate at the time of impact. Using the Mars Orbiter Laser Altimeter (MOLA) data set, quantitative information about the strength of the upper crust and the dynamics of Martian ejecta blankets may be derived from crater geometry measurements.
    [Show full text]
  • 16. Ice in the Martian Regolith
    16. ICE IN THE MARTIAN REGOLITH S. W. SQUYRES Cornell University S. M. CLIFFORD Lunar and Planetary Institute R. O. KUZMIN V.I. Vernadsky Institute J. R. ZIMBELMAN Smithsonian Institution and F. M. COSTARD Laboratoire de Geographie Physique Geologic evidence indicates that the Martian surface has been substantially modified by the action of liquid water, and that much of that water still resides beneath the surface as ground ice. The pore volume of the Martian regolith is substantial, and a large amount of this volume can be expected to be at tem- peratures cold enough for ice to be present. Calculations of the thermodynamic stability of ground ice on Mars suggest that it can exist very close to the surface at high latitudes, but can persist only at substantial depths near the equator. Impact craters with distinctive lobale ejecta deposits are common on Mars. These rampart craters apparently owe their morphology to fluidhation of sub- surface materials, perhaps by the melting of ground ice, during impact events. If this interpretation is correct, then the size frequency distribution of rampart 523 524 S. W. SQUYRES ET AL. craters is broadly consistent with the depth distribution of ice inferred from stability calculations. A variety of observed Martian landforms can be attrib- uted to creep of the Martian regolith abetted by deformation of ground ice. Global mapping of creep features also supports the idea that ice is present in near-surface materials at latitudes higher than ± 30°, and suggests that ice is largely absent from such materials at lower latitudes. Other morphologic fea- tures on Mars that may result from the present or former existence of ground ice include chaotic terrain, thermokarst and patterned ground.
    [Show full text]
  • A Study About the Temporal Constraints on the Martian Yardangs’ Development in Medusae Fossae Formation
    remote sensing Article A Study about the Temporal Constraints on the Martian Yardangs’ Development in Medusae Fossae Formation Jia Liu 1,2 , Zongyu Yue 1,3,*, Kaichang Di 1,3 , Sheng Gou 1,4 and Shengli Niu 4 1 State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China; [email protected] (J.L.); [email protected] (K.D.); [email protected] (S.G.) 2 University of Chinese Academy of Sciences, Beijing 100049, China 3 CAS Center for Excellence in Comparative Planetology, Hefei 230026, China 4 State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau 999078, China; [email protected] * Correspondence: [email protected]; Tel.: +86-10-64889553 Abstract: The age of Mars yardangs is significant in studying their development and the evolution of paleoclimate conditions. For planetary surface or landforms, a common method for dating is based on the frequency and size distribution of all the superposed craters after they are formed. However, there is usually a long duration for the yardangs’ formation, and they will alter the superposed craters, making it impossible to give a reliable dating result with the method. An indirect method by analyzing the ages of the superposed layered ejecta was devised in the research. First, the layered ejecta that are superposed on and not altered by the yardangs are identified and mapped. Then, the ages of the layered ejecta are derived according to the crater frequency and size distribution on them. These ages indicate that the yardangs ceased development by these times, and the ages are valuable for studying the evolution of the yardangs.
    [Show full text]
  • Standardizing the Nomenclature of Martian Impact Crater Ejecta
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by OpenKnowledge@NAU JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 105, NO. Ell, PAGES 26,733-26,738,NOVEMBER 25, 2000 Standardizing the nomenclature of Martian impact crater ejeeta morphologies NadineG. Barlow •, JosephM. Boyce2,Francois M. Costard3,Robert A. Craddock4, JamesB. Garvins, Susan E. H. Sakimotos,Ruslan O. Kuzmin6,David J. Roddy 7, and LaurenceA. Soderblom7 Abstract. The Mars CraterMorphology Consortium recommends the useof a standardized nomenclaturesystem when discussing Martian impact crater ejecta morphologies. The system utilizesnongenetic descriptors to identifythe variousejecta morphologies seen on Mars. This systemis designedto facilitatecommunication and collaborationbetween researchers. Crater morphologydatabases will be archivedthrough the U.S. GeologicalSurvey in Flagstaff,where a comprehensivecatalog of Martian cratermorphologic information will be maintained. 1. Introduction andFrawley, 1998; Gamin et al., 1999],and the generalgeologic history of the planet [Soderblomet al., 1974; Tanaka, 1986; Fresh Martian impact craters are typically surroundedby Barlow, 1988; Hartmann, 1999]. ejectastructures that differ in morphologyfrom the radial ejecta This articledescribes a systemof nomenclaturerecommended patternsseen around lunar and Mercurian craters. The Martian by the Mars Crater MorphologyConsortium for use when ejectastructures are typically composedof one or more layersof describing Martian impact structures. The Consortium, material,
    [Show full text]
  • Morphology and Morphometry of Double Layered Ejecta Craters on Mars
    Western University Scholarship@Western Electronic Thesis and Dissertation Repository August 2015 Morphology and Morphometry of Double Layered Ejecta Craters on Mars Ryan Schwegman The University of Western Ontario Supervisor Dr. Gordon Osinski The University of Western Ontario Joint Supervisor Dr. Livio Tornabene The University of Western Ontario Graduate Program in Geology A thesis submitted in partial fulfillment of the equirr ements for the degree in Master of Science © Ryan Schwegman 2015 Follow this and additional works at: https://ir.lib.uwo.ca/etd Part of the Geology Commons Recommended Citation Schwegman, Ryan, "Morphology and Morphometry of Double Layered Ejecta Craters on Mars" (2015). Electronic Thesis and Dissertation Repository. 3074. https://ir.lib.uwo.ca/etd/3074 This Dissertation/Thesis is brought to you for free and open access by Scholarship@Western. It has been accepted for inclusion in Electronic Thesis and Dissertation Repository by an authorized administrator of Scholarship@Western. For more information, please contact [email protected]. MORPHOLOGY AND MORPHOMETRY OF DOUBLE LAYERED EJECTA CRATERS ON MARS (Thesis format: Integrated Article) by Ryan Schwegman Graduate Program in Geology: Planetary Science A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science The School of Graduate and Postdoctoral Studies The University of Western Ontario London, Ontario, Canada © Ryan Schwegman 2015 Abstract Double layered ejecta (DLE) craters display two distinct layers of ejecta that appear to have been emplaced as a mobile, ground-hugging flow. While volatile content within the target, atmosphere, or some combination of the two is generally considered a major variable enhancing the mobility of ejecta, the presence of unconsolidated surface materials may also have some effect.
    [Show full text]
  • Rampart Craters on Ganymede: Their Implications for Fluidized Ejecta Emplacement
    Meteoritics & Planetary Science 45, Nr 4, 638–661 (2010) doi: 10.1111/j.1945-5100.2010.01044.x Rampart craters on Ganymede: Their implications for fluidized ejecta emplacement Joseph BOYCE1*, Nadine BARLOW2, Peter MOUGINIS-MARK1, and Sarah STEWART3 1Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, Hawaii 96922, USA 2Department of Physics and Astronomy, Northern Arizona University, Flagstaff, Arizona 86001, USA 3Department of Earth and Planetary Science, Harvard University, Cambridge, Massachusetts 02138, USA *Corresponding author. E-mail: [email protected] (Received 03 December 2008; revision accepted 12 February 2010) Abstract–Some fresh impact craters on Ganymede have the overall ejecta morphology similar to Martian double-layer ejecta (DLE), with the exception of the crater Nergal that is most like Martian single layer ejecta (SLE) craters (as is the terrestrial crater Lonar). Similar craters also have been identified on Europa, but no outer ejecta layer has been found on these craters. The morphometry of these craters suggests that the types of layered ejecta craters identified by Barlow et al. (2000) are fundamental. In addition, the mere existence of these craters on Ganymede and Europa suggests that an atmosphere is not required for ejecta fluidization, nor can ejecta fluidization be explained by the flow of dry ejecta. Moreover, the absence of fluidized ejecta on other icy bodies suggests that abundant volatiles in the target also may not be the sole cause of ejecta fluidization. The restriction of these craters to the grooved terrain of Ganymede and the concentration of Martian DLE craters on the northern lowlands suggests that these terrains may share key characteristics that control the development of the ejecta of these craters.
    [Show full text]
  • Rampart Craters Team Mu
    Rampart Craters Team Mu Introduc3on Science Queson: Can Rampart Crater raos be used to determine differences in Rampart Crater sizes found at different Northern latude bands? (90N – 80N, 80N – 70N, 70N – 60N, 60N – 50N) Introduc3on Ques3on Importance: Our ques3on can help the people of earth determine the amount of ice located underneath Mar’s surface around the north pole. Introduc3on Main Hypothesis: Rampart Crater raos can be used to determine differences in Rampart Crater sizes found at different Northern latude bands. More ice will be found in the area located at 50N – 60N. Alternate Hypothesis: Rampart Crater raos can’t be used to determine differences in Rampart Crater sizes found at different Northern latude bands. More ice will be found in the area located at 80N – 90N. Definions Terms: Rampart Crater – A specific type of crater which accompanied by dis3nc3ve fluidized ejecta. Lobate Ejecta - Formed when meteor makes impact with water/ice beneath the surface causing it to look like its flowing away from the crater, like dropping ball into a pile of mud. Rao – The diameter of the rampart crater divided by the length of the ejecta. Background Rampart Crater Lobate Ejecta Raised Rim Image ID: P17_007543_2508_70N302W Background Ramparts Craters-are formed when the meteor strikes, it hits ice/water causing Lobate Ejecta. Lobate Ejecta looks as if its flowing away from the crater. Mars Image of Earth’s Image of a Rampart Crater “Rampart Crater” hhp://3.arc.nasa.gov Background “We find that only a few basic physical processes are necessary to form sharp distal ramparts. First, there must be sufficient material to form a con3nuum overland flow.
    [Show full text]
  • The Mars Global Surveyor Mars Orbiter Camera: Interplanetary Cruise Through Primary Mission
    p. 1 The Mars Global Surveyor Mars Orbiter Camera: Interplanetary Cruise through Primary Mission Michael C. Malin and Kenneth S. Edgett Malin Space Science Systems P.O. Box 910148 San Diego CA 92130-0148 (note to JGR: please do not publish e-mail addresses) ABSTRACT More than three years of high resolution (1.5 to 20 m/pixel) photographic observations of the surface of Mars have dramatically changed our view of that planet. Among the most important observations and interpretations derived therefrom are that much of Mars, at least to depths of several kilometers, is layered; that substantial portions of the planet have experienced burial and subsequent exhumation; that layered and massive units, many kilometers thick, appear to reflect an ancient period of large- scale erosion and deposition within what are now the ancient heavily cratered regions of Mars; and that processes previously unsuspected, including gully-forming fluid action and burial and exhumation of large tracts of land, have operated within near- contemporary times. These and many other attributes of the planet argue for a complex geology and complicated history. INTRODUCTION Successive improvements in image quality or resolution are often accompanied by new and important insights into planetary geology that would not otherwise be attained. From the variety of landforms and processes observed from previous missions to the planet Mars, it has long been anticipated that understanding of Mars would greatly benefit from increases in image spatial resolution. p. 2 The Mars Observer Camera (MOC) was initially selected for flight aboard the Mars Observer (MO) spacecraft [Malin et al., 1991, 1992].
    [Show full text]
  • Ages and Onset Diameters of Rampart Craters in Equatorial Regions on Mars
    Role of Volatiles and Atmospheres on Martian Impact Craters 2005 3012.pdf AGES AND ONSET DIAMETERS OF RAMPART CRATERS IN EQUATORIAL REGIONS ON MARS. D. Reiss1, S. van Gasselt2, E. Hauber1, G. Michael1, R. Jaumann1, G. Neukum2 and the HRSC Co-Investigator Team. 1Institute of Planetary Research, DLR, Rutherfordstr. 2, 12489 Berlin, Germany ([email protected]) 2Institute for Geosciences, Freie Universitaet Berlin, Malteserstr. 74-100, 12249 Berlin, Germany. Introduction: Many large craters on Mars exhibit [13] (Figure 2A). The formation rate of rampart craters ejecta blankets which are not observed on other terres- declines in the Hesperian, whereas the onset diameters trial planets like the Moon [1]. As found by many re- increase. At the Hesperian-Amazonian boundary the searchers [e.g. 2, 3, 4] the morphology is suggested to formation comes to an end. This might indicate a low- be caused by volatile rich target material [2] or atmos- ering of the ground ice table with time which in Xan- pheric effects [5]. However, in a given area a certain the Terra, if present at all, could be several kilometers minimum diameter exists for craters which show fluid- deep in present days. Either all the ground ice was lost ized ejecta blankets [6, 7], called the onset diameter. with time due to diffusion to the atmosphere [e.g. 14] Geographic mapping shows a latitude dependence of or there is still a deep ground ice layer which can only the onset diameters [8, 9]. In equatorial regions the be reached by relatively large (and in recent times rare) onset diameters are typically 4 to 7 km versus 1 to 2 impacts.
    [Show full text]
  • Effect of Volatiles and Target Lithology on the Generation and Emplacement of Impact Crater Fill and Ejecta Deposits on Mars
    Effect of volatiles and target lithology on the generation and emplacement of impact crater fill and ejecta deposits on Mars Item Type Proceedings; text Authors Osinski, Gordon R. Citation Osinski, G. R. (2006). Effect of volatiles and target lithology on the generation and emplacement of impact crater fill and ejecta deposits on Mars. Meteoritics & Planetary Science, 41(10), 1571-1586. DOI 10.1111/j.1945-5100.2006.tb00436.x Publisher The Meteoritical Society Journal Meteoritics & Planetary Science Rights Copyright © The Meteoritical Society Download date 26/09/2021 23:08:45 Item License http://rightsstatements.org/vocab/InC/1.0/ Version Final published version Link to Item http://hdl.handle.net/10150/656199 Meteoritics & Planetary Science 41, Nr 10, 1571–1586 (2006) Abstract available online at http://meteoritics.org Effect of volatiles and target lithology on the generation and emplacement of impact crater fill and ejecta deposits on Mars Gordon R. OSINSKI Canadian Space Agency, 6767 Route de l’Aeroport, Saint-Hubert, Quebec, J3Y 8Y9, Canada E-mail: [email protected] (Received 15 October 2005; revision accepted 15 March 2006) Abstract–Impact cratering is an important geological process on Mars and the nature of Martian impact craters may provide important information as to the volatile content of the Martian crust. Terrestrial impact structures currently provide the only ground-truth data as to the role of volatiles and an atmosphere on the impact-cratering process. Recent advancements, based on studies of several well-preserved terrestrial craters, have been made regarding the role and effect of volatiles on the impact-cratering process. Combined field and laboratory studies reveal that impact melting is much more common in volatile-rich targets than previously thought, so impact-melt rocks, melt-bearing breccias, and glasses should be common on Mars.
    [Show full text]
  • Ground-Ice Distribution on Mars Based on Gis Analysis
    Lunar and Planetary Science XXIX 1173.pdf GROUND-ICE DISTRIBUTION ON MARS BASED ON GIS ANALYSIS. F. Costard1 and J.P.Gosset². 1Laboratoire de Géologie Dynamique de la Terre et des Planètes, 91405 Orsay Cédex, France. ² Centre de Ressources Informatiques, Université de Caen, 14032 Caen, France. [email protected] Introduction. In order to quantify the spatial in large topographic basins near and below –1000 distribution of martian ground-ice, a global study m, especially in areas that are close to the con- of rampart craters was undertaken to determine vergent terminations of outflow channels (8). their temporal and spatial relations with the sur- - At about 41°S, 257°W to the east of Hellas rounding morphostructural units. Rampart craters Planitia, a regional concentration of rampart cra- all over planet Mars have been systematically ters suggests the presence of a volatile-rich measured and mapped using a GIS database of sedimentary plain at the mouth of Harmaklis, geologic and topographic informations (1). Ma’adim and Reull Valles. The occurrence in the Methodology. Rampart crater ejecta mor- same area of three channels, at a latitude higher phologies are the result from impact into subsur- than 40° and within a topographic basin are opti- face volatile reservoirs with different physical or mal conditions for the development of a perma- structural properties (2,3,4,5,6). In order to pro- nent ground-ice (2). duce statistically significant results, all rampart - This GIS analysis reveals a linear concentra- craters that are visible in 1:2000000-scale Viking tion of rampart craters along Kasei Valles.
    [Show full text]
  • Ebook < Impact Craters on Mars # Download
    7QJ1F2HIVR # Impact craters on Mars « Doc Impact craters on Mars By - Reference Series Books LLC Mrz 2012, 2012. Taschenbuch. Book Condition: Neu. 254x192x10 mm. This item is printed on demand - Print on Demand Neuware - Source: Wikipedia. Pages: 50. Chapters: List of craters on Mars: A-L, List of craters on Mars: M-Z, Ross Crater, Hellas Planitia, Victoria, Endurance, Eberswalde, Eagle, Endeavour, Gusev, Mariner, Hale, Tooting, Zunil, Yuty, Miyamoto, Holden, Oudemans, Lyot, Becquerel, Aram Chaos, Nicholson, Columbus, Henry, Erebus, Schiaparelli, Jezero, Bonneville, Gale, Rampart crater, Ptolemaeus, Nereus, Zumba, Huygens, Moreux, Galle, Antoniadi, Vostok, Wislicenus, Penticton, Russell, Tikhonravov, Newton, Dinorwic, Airy-0, Mojave, Virrat, Vernal, Koga, Secchi, Pedestal crater, Beagle, List of catenae on Mars, Santa Maria, Denning, Caxias, Sripur, Llanesco, Tugaske, Heimdal, Nhill, Beer, Brashear Crater, Cassini, Mädler, Terby, Vishniac, Asimov, Emma Dean, Iazu, Lomonosov, Fram, Lowell, Ritchey, Dawes, Atlantis basin, Bouguer Crater, Hutton, Reuyl, Porter, Molesworth, Cerulli, Heinlein, Lockyer, Kepler, Kunowsky, Milankovic, Korolev, Canso, Herschel, Escalante, Proctor, Davies, Boeddicker, Flaugergues, Persbo, Crivitz, Saheki, Crommlin, Sibu, Bernard, Gold, Kinkora, Trouvelot, Orson Welles, Dromore, Philips, Tractus Catena, Lod, Bok, Stokes, Pickering, Eddie, Curie, Bonestell, Hartwig, Schaeberle, Bond, Pettit, Fesenkov, Púnsk, Dejnev, Maunder, Mohawk, Green, Tycho Brahe, Arandas, Pangboche, Arago, Semeykin, Pasteur, Rabe, Sagan, Thira, Gilbert, Arkhangelsky, Burroughs, Kaiser, Spallanzani, Galdakao, Baltisk, Bacolor, Timbuktu,... READ ONLINE [ 7.66 MB ] Reviews If you need to adding benefit, a must buy book. Better then never, though i am quite late in start reading this one. I discovered this publication from my i and dad advised this pdf to find out. -- Mrs. Glenda Rodriguez A brand new e-book with a new viewpoint.
    [Show full text]