University of Central Florida STARS Faculty Bibliography 2000s Faculty Bibliography 1-1-2000 Standardizing the nomenclature of Martian impact crater ejecta morphologies Nadine G. Barlow University of Central Florida Joseph M. Boyce François M. Costard Robert A. Craddock James B. Garvin See next page for additional authors Find similar works at: https://stars.library.ucf.edu/facultybib2000 University of Central Florida Libraries http://library.ucf.edu This Article is brought to you for free and open access by the Faculty Bibliography at STARS. It has been accepted for inclusion in Faculty Bibliography 2000s by an authorized administrator of STARS. For more information, please contact [email protected]. Recommended Citation Barlow, Nadine G.; Boyce, Joseph M.; Costard, François M.; Craddock, Robert A.; Garvin, James B.; Sakimoto, Susan E. H.; Kuzmin, Ruslan O.; Roddy, David J.; and Soderblom, Laurence A., "Standardizing the nomenclature of Martian impact crater ejecta morphologies" (2000). Faculty Bibliography 2000s. 2431. https://stars.library.ucf.edu/facultybib2000/2431 Authors Nadine G. Barlow, Joseph M. Boyce, François M. Costard, Robert A. Craddock, James B. Garvin, Susan E. H. Sakimoto, Ruslan O. Kuzmin, David J. Roddy, and Laurence A. Soderblom This article is available at STARS: https://stars.library.ucf.edu/facultybib2000/2431 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, commonly displayed in a lobed pattern. These composedof this article'sauthors, met at the U.S. Geological structureshave been described by a number of adjectives, Surveyin Flagstaff,Arizona, in May 1998 and July 1999 to including fluidized, lobate, rampart, splosh, and flower. discussand developthese recommendations. The Consortium Although originally thoughtto be the result of wind erosionon membershave been actively involvedin utilizing Martian impact the basisof Mariner 9 image analysis[McCauley, 1973; Amidson cratersin a numberof studiesover the past20 years,and several et al., 1976], Viking Orbiter imagesrevealed that thesestructures haveproduced catalogs of cratercharacteristics. These databases were distributedglobally and likely the resultof emplacementby contain information that is often complementaryto but not fluidization processes,either from impact into and vaporization containedin the other crater catalogs. One of the goalsof the of subsurfacevolatiles [Cart et al., 1977; Wohletzand Sheridan, Mars CraterMorphology Consortium is to combinethe existing 1983] or by ejecta entrainmentby the thin Martian atmosphere crater databasesinto one system that can be queried for [Schultz and Gault, 1979; Barnouin-Jha and Schultz, 1998]. informationon crater location,size, shape,preservational state, Now as more details about the ejecta morphologies and ejectaand interiorstructures, and morphometriccharacteristics morphometriesbecome available becauseof the Mars Global (craterdepth, rim height,central peak height and width, central Surveyorand upcomingMars Surveyormissions, it is apparent pit diameterand depth, ejecta extent and sinuosity, etc.). Because that a standardizedsystem of nomenclatureis neededto facilitate of the variety of classificationsystems, many using different the exchangeof data between researcherswho compile crater terminologyto describethe samemorphology, the Consortium data for use in studies on erosional history [Craddock and agreedthat the first courseof actionwas to standardizethe Maxwell, 1990, 1993; Craddock et al., 1997; Grant and Schultz, nomenclaturefor cratermorphologic features. The first features 1990, 1993; Barlow, 1995; Hartmann and Esquerdo, 1999], to be standardizedare the ejectamorphologies. implicationsfor subsurfacevolatiles [Cintala and Mouginis- Mark, 1980; Mouginis-Mark, 1981, 1987; Kuzmin et al., 1988; Costard, 1989; Barlow and Bradley, 1990; Barlow, 1994; Boyce 2. Recommendations and Roddy, 1997; Costard and Gosset, 1998; Demura and Kurita, 1998], cratermorphometries and formation[Roddy, 1977; Martian ejecta blankets have been classified into many Cintala et al., 1976; Wood et al., 1978; Melosh, 1989; Gamin differentgroups because of the rangeof morphologiesidentified from the Viking Orbiter imagery. However, in general,the •Departmentof Physics, University of CentralFlorida, Orlando. morphologiescan be dividedinto threemain groups: 2Officeof SpaceScience, NASA Headquarters, Washington, D.C. 1. Layered ejecta patterns,where the ejecta blanket is 3CNRS/Laboratoirede GeologieDynamique de la Terre et des composedof one or more completeor partialsheets of material Planetes,Orsay, France. surroundingthe crater, appear to have been emplacedby 4Centerfor Earthand PlanetaryStudies, National Air and Space fluidizationprocesses, although some structures show evidence Museum,Smithsonian Institution, Washington, D.C. 5NASAGoddard Space Flight Center, Greenbelt, Maryland. of subsequenteolian erosion. 6VernadskyInstitute, Russian Academy of Sciences,Moscow, Russia. 2. Radial ejecta blankets,which are similar to the ejecta 7U.S.Geological Survey, Flagstaff, Arizona. patternsaround lunar and Mercuriancraters, are believedto be emplaced by secondarymaterial ejected along ballistic Copyright2000 by the AmericanGeophysical Union. trajectories. Papernumber 2000JE001258. 3. Combination structuresshow both layered and radial 0148-0227/00/2000JE001258509.00 patterns. 26,733 26,734 BARLOW ET AL.: MARTIAN IMPACT CRATER NOMENCLATURE Table 1. Correlationof New MorphologyTerminology With PreviousNomenclature Nomenclature Reference Layered Ejecta Structures Pedestal(P) Pedestal McCauley [ 1973] Pedestal Amidsonet al. [ 1976] Pedestal Head and Roth [1976] Mound Johansen[1979] Lump Johansen[ 1979] Single-layerpancake (SLEPC/SLEPS) Polar Johansen[ 1979] Type 6 Mouginis-Mark[ 1979] SS Horner and Greeley[ 1987] Type 3 Costard[1989] Pancake Barlow and Bradley [ 1990] Single-layerrampart (SLERC/SLERS) Type 1 Mouginis-Mark[ 1979] Class4 Blasiusand Cutts [1980] SR Horner and Greeley[ 1987] Type 1/flower Costard[1989] Singlelobe Barlowand Bradley[ 1990] Double-layerrampart (DLERC/DLERS) Composite Johansen[ 1979] Type 2 Mouginis-Mark[ 1979] Class3 Blasiusand Cutts [1980] D Horner and Greeley[ 1987] Type 2/rampart Costard[1989] Double lobe Barlow and Bradley [1990] Multiple-layer rampart(MLERS) Flower Johansen[1979] Type 3 Mouginis-Mark[ 1979] Class2/flower Blasiusand Cutts [ 1980] MR Horner and Greeley[1987] Multiple lobe Barlowand Bradley [1990] Radial Morphologies Radial (SLER) Lunar riohansen[1979] Class 1/lunar Blasiusand Cutts [1980] Type 4 Mouginis-Mark[ 1979] Radial Barlow and Bradley [1990] CombinationMorphologies (e.g., SLERSR) Transitional riohansen[ 1979] Type 5 Mouginis-Mark[ 1979] Diverse Barlow and Bradley [ 1990] Table 1 providesa listing of someof the terminologythat has 3. Layered ejecta craterssurrounded by three or more beenused to describecraters in thesebasic groups. completeor partiallayers of materialshall be called"multiple- The Mars Crater Morphology Consortiumrecommends the layer ejecta"(MLE) (Figure l d). following changesin nomenclature: 4. The single-layer, double-layer,and multiple-layer First, layered ejecta patternsthat have undergonesubstantial categoriesare further modified by termsdescribing the shapeof erosionowing to eolian activity, resultingin the craterand ejecta the ejectaterminus. Those layered ejecta patterns terminated by being perchedabove the surroundingterrain, shall be referredto a distalridge or rampartshall be modifiedby theterm "rampart" as "pedestalcraters" (Pd). The ejectablanket of a pedestalcrater (R) (i.e., Figure l d). Hence a single-layeredejecta pattern is typified by a sharpedge (no distal ridge) that dropsoff to the terminatedin a distalridge would be calleda "single-layerejecta lower elevationof the surroundingterrain (Figure l a). rampart." Layeredejecta patterns that terminatein a concave Second, other layered ejecta patternsshall be referred to as slopewill bemodified by theterm "pancake" (P) (Figure1 e). "layeredejecta craters" (LE). 5. The rampartand pancake terms are further modified by the 1. Layered ejectacraters surrounded by only a singlelayer of adjectives"sinuous" (S) (i.e., Figurel d)