Geological Processes and Evolution
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Formation of Gullies on Mars: Link to Recent Climate History and Insolation Microenvironments Implicate Surface Water Flow Origin
Formation of gullies on Mars: Link to recent climate history and insolation microenvironments implicate surface water flow origin James W. Head*†, David R. Marchant‡, and Mikhail A. Kreslavsky*§ *Department of Geological Sciences, Brown University, Providence, RI 02912; ‡Department of Earth Sciences, Boston University, Boston, MA 02215; and §Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064 Edited by John Imbrie, Brown University, Providence, RI, and approved July 18, 2008 (received for review April 17, 2008) Features seen in portions of a typical midlatitude Martian impact provide a context and framework of information in which their crater show that gully formation follows a geologically recent origin might be better understood. Assessment of the stratigraphic period of midlatitude glaciation. Geological evidence indicates relationships in a crater interior typical of many gully occurrences that, in the relatively recent past, sufficient snow and ice accumu- provides evidence that gully formation is linked to glaciation and to lated on the pole-facing crater wall to cause glacial flow and filling geologically recent climate change that provided conditions for of the crater floor with debris-covered glaciers. As glaciation snow/ice accumulation and top-down melting. waned, debris-covered glaciers ceased flowing, accumulation The distribution of gullies shows a latitudinal dependence on zones lost ice, and newly exposed wall alcoves continued as the Mars, exclusively poleward of 30° in each hemisphere (2, 14) with location for limited snow/frost deposition, entrapment, and pres- a distinct concentration in the 30–50° latitude bands (e.g., 2, 7, ervation. Analysis of the insolation geometry of this pole-facing 8, 14, 18). -
Noachian Highland Crater Degradation on Mars: Assessing the Role of Regional Snow and Ice Deposits in a Cold and Icy Early Mars
45th Lunar and Planetary Science Conference (2014) 1077.pdf NOACHIAN HIGHLAND CRATER DEGRADATION ON MARS: ASSESSING THE ROLE OF REGIONAL SNOW AND ICE DEPOSITS IN A COLD AND ICY EARLY MARS. D. K. Weiss1 and J. W. Head1, 1Department of Geological Sciences, Brown University, Providence, RI 02912, U.S.A. ([email protected]) Introduction: The faint young sun [1,2] has led to the supposition that early Mars was cold [3-5]. The pres- ence of valley networks and the degraded state of high- land craters, however, has led many investigators to sug- gest that the martian climate in the Noachian was warm and wet, and that precipitation [6] in the form of rainfall [7] and fluvial activity are the likely causes of crater deg- radation. Recent climate models, however, have shown that climactic conditions in the Noachian could not have supported liquid water precipitation [8,9], and that re- gional snow and ice deposits, much like those inferred to be present in the Amazonian (Fig. 1) [10], pervaded the Noachian highlands [11]. Recent climate models have shown however, that unlike the Amazonian, slightly in- creased atmospheric pressures in the Noachian could allow the atmosphere to behave adiabatically [8], a sce- nario in which the Noachian southern highlands acts as a Figure 2. Typical Noachian highland crater and characteristics. cold trap and preferentially accumulates atmospheric suggests that they have been heavily degraded [7], alt- snow and ice deposits [11, 12]. Martian Noachian high- hough the mode of degradation has been debated (see land craters may give insight into conditions on early [7]). -
Martian Perched Craters and Large Ejecta Volume: Evidence for Episodes of Deflation in the Northern Lowlands
Meteoritics & Planetary Science 41, Nr 10, 1647–1658 (2006) Abstract available online at http://meteoritics.org Martian perched craters and large ejecta volume: Evidence for episodes of deflation in the northern lowlands Sandrine MERESSE1*, François COSTARD1, Nicolas MANGOLD1, David BARATOUX2, and Joseph M. BOYCE3 1Laboratoire IDES-Orsay, Université Paris-Sud, UMR 8148, Bat 509, 91405 Orsay, France 2Observatoire Midi-Pyrénées, UMR 5562, 31400 Toulouse, France 3Hawai’i Institute of Geophysics and Planetology, University of Hawai’i at Manoa, Honolulu, Hawai’i, USA *Corresponding author. E-mail: [email protected] (Received 28 October 2005; revision accepted 30 June 2006) Abstract–The northern lowland plains, such as those found in Acidalia and Utopia Planitia, have high percentages of impact craters with fluidized ejecta. In both regions, the analysis of crater geometry from Mars Orbiter Laser Altimeter (MOLA) data has revealed large ejecta volumes, some exceeding the volume of excavation. Moreover, some of the crater cavities and fluidized ejecta blankets of these craters are topographically perched above the surrounding plains. These perched craters are concentrated between 40 and 70°N in the northern plains. The atypical high volumes of the ejecta and the perched craters suggest that the northern lowlands have experienced one or more episodes of resurfacing that involved deposition and erosion. The removal of material, most likely caused by the sublimation of ice in the materials and their subsequent erosion and transport by the wind, is more rapid on the plains than on the ejecta blankets. The thermal inertia difference between the ejecta and the surrounding plains suggests that ejecta, characterized by a lower thermal inertia, protect the underneath terrain from sublimation. -
Estimating the Volume of Glacial Ice on Mars
EPSC Abstracts Vol. 8, EPSC2013-111, 2013 European Planetary Science Congress 2013 EEuropeaPn PlanetarSy Science CCongress c Author(s) 2013 Estimating the volume of glacial ice on Mars: Geographic and geometric constraints on concentric crater fill, lineated valley fill, and lobate debris aprons along the Martian dichotomy boundary C. Fassett (1), J. Levy (2) and J. Head (3) (1) Mount Holyoke College, South Hadley, MA, USA (2) University of Texas at Austin, USA (3) Brown University, Providence, RI, USA ([email protected]) Abstract Once the spatial extent of these features was established, we are using geometric tools to infer the Landforms inferred to have formed from volumetric extent of glacial landforms. For example, glacial processes are abundant on Mars and include for CCF, several morphometric properties were features such as concentric crater fill (CCF), lobate extracted from catalogues of northern hemisphere debris aprons (LDA), and lineated valley fill (LVF). crater morphologies [13] including: crater diameter, Here, we present new mapping of the spatial extent d and measured crater depth, Dm. CCF fill radius, rf of these landforms derived from CTX and THEMIS is measured from CTX images of the crater, VIS image data, and new geometric constraints on measured along two orthogonal profiles that span the the volume of glaciogenic fill material present in spatial limit of “brain terrain” surface texture or concentric crater fill deposits. concentric surface lineations. Using these quantities measured from MOLA 1. Introduction and CTX data, relationships between fresh-crater Debris-covered glacial landforms such as depths and diameters on Mars [14], coupled with CCF, LVF, and LDA are widespread on Mars and elementary calculus (solids of rotation), permit us to have been long inferred to represent locations of make quantitative estimates of CCF fill volume (note: abundant ground ice preserved at mid-latitude this method does not distinguish between prior fill locations [1-12]. -
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. -
What Is the Zuni Sandstone Today
What is the ZuniSandstone Today -- 100 Years AfterDutton? A Discussion andReview of JurassicStratigraphy in West-Central New Mexico NEW MEXICO BUREAU OF MINES AND MINERAL RESOURCES OPEN-FILE REPORT 174 by Orin J. Anderson New MexicoBureau of Minesand Mineral Resources 1983 Contents Introduction P. 1 Discussion P. 3 Todilto Limestone - Navajo Sandstone P- 5 San Rafael Group Defined P. 8 Glen CanyonGroup Defined P. 9 MorrisonFormation Subdivided p. 14 Cow SpringsSandstone p. 17 1956 Memorandum from C. H. Dane p. 22 Zuni Sandstone Redefined p. 26 Summary p. 28 ReferencesCited p. 30 Figures Fig. 1 Index map of study area Fig. 2 Stratigraphic nomenclature and correlationchart- 1885 to present Fig. 3 Measured section at type locality of Zuni Sandstone (inside back cover) Fig. 4 Stratigraphiccross-section-Dakota and Zuni sandstones, showing southward thinning of Zuni Sandstone (inside back cover) WHAT IS THE ZUNISANDSTONE TODAY -- 100 YEARS AFTER DUTTON? A DISCUSSION AND REVIEW OF JURASSICSTRATIGRAPHY IN WEST-CENTRAL NEW MEXICO Introduction The massivesequence(s) of light colored, cross bedded sandstonesthat underliethe Dakota Sandstone (Upper Cretaceous) in west-central New Mexico and northeasternArizona were first described and namedby CaptainClarence E. Dutton ofthe U. S. Army Ordinance Corps. His reportentitled "Mount Taylor and the Zuni Plateau"(Dutton, 1885) contains an account of the stratigraphy and structure of those two areas and theimmediately surrounding region(the Zuni Plateau is thepresent day Zuni uplift). In thereport he described a "massive bright redsandstone" that overlies the "basal Triassediments" (the present day ChinleFormation) in theFort Wingate area; this unit henamed "provisionally"the Wingate Sandstone. Overlyingthe Wingate Dutton recognized "a series ofsandstones and sandy shales ..... -
Stratigraphy and Sedimentology of a Dry to Wet Eolian Depositional System, Burns Formation, Meridiani Planum, Mars
Earth and Planetary Science Letters 240 (2005) 11–72 www.elsevier.com/locate/epsl Stratigraphy and sedimentology of a dry to wet eolian depositional system, Burns formation, Meridiani Planum, Mars J.P. Grotzinger a,*, R.E. Arvidson b, J.F. Bell III c, W. Calvin d, B.C. Clark e, D.A. Fike a, M. Golombek f, R. Greeley g, A. Haldemann f, K.E. Herkenhoff h, B.L. Jolliff b, A.H. Knoll i, M. Malin j, S.M. McLennan k, T. Parker e, L. Soderblom g, J.N. Sohl-Dickstein b, S.W. Squyres b, N.J. Tosca k, W.A. Watters a a Massachusetts Inst. of Technology, Earth, Atmos. and Planetary Sci., Cambridge, MA 02139, USA b Department Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA c Department of Astronomy, Space Sciences Bldg. Cornell University, Ithaca, NY 14853, USA d University of Nevada, Reno, NV 89501, USA e Lockheed Martin Corporation, Littleton, CO 80127, USA f Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA g Department Geological Sciences, Arizona State University, Box 871404, Tempe, AZ 85287-1404, USA h U.S. Geological Survey, Flagstaff, AZ 86001, USA i Botanical Museum, Harvard University, Cambridge MA 02138, USA j Malin Space Science Systems, Inc., San Diego, CA 92191, USA k Department of Geosciences, State University of New York, Stony Brook, NY 11794-2100, USA Accepted 22 September 2005 Editor: A.N. Halliday Abstract Outcrop exposures of sedimentary rocks at the Opportunity landing site (Meridiani Planum) form a set of genetically related strata defined here informally as the Burns formation. -
Concentric Crater Fill: Rates of Glacial Accumulation, Infilling and Deglaciation in the Amazonian and Noachian of Mars
45th Lunar and Planetary Science Conference (2014) 1227.pdf CONCENTRIC CRATER FILL: RATES OF GLACIAL ACCUMULATION, INFILLING AND DEGLACIATION IN THE AMAZONIAN AND NOACHIAN OF MARS. James L. Fastook1 and James W. Head2, 1University of Maine, Orono, ME 04469, [email protected], 2Brown University, Providence, RI 02912. Introduction: Concentric Crater Fill (CCF) [1-6] is low the crater rim crest, debris is deposited locally on the one of many features on Mars that are thought to either ice surface in the crater interior, and then transported contain ice, or to have been formed by a glaciological with the movement of the downward and inward-flowing process that involved the deformation and movement of ice. To characterize the two cases we perform experi- a significant thickness of ice, emplaced during a climatic ments to see how long it takes for a modeled crater to fill period when the obliquity and other spin-orbital parame- to a level that matches the Fig. 1 observed CCF crater ters favored deposition in areas where ice is not currently [3]. Fig. 2 shows the two cases. stable [7-10]. Such features include Tropical Mountain a) Single Episode: 200 m Glaciers [11-15], Lobate Debris Aprons, and Lineated 200 Valley Fill [12, 16-28]. Others, such as Pedestal, 0 Perched, and Excess Ejecta Craters [29-32], record the -200 presence of widespread mantling. Features that preserve -400 ice presumably do so by covering the ice surface with a thin (< 15 m) layer of debris [33-37]. In all cases, under- -600 -800 standing the mechanism that leads to the formation of Elevation (m) these features provides insights into the state of the cur- -1000 rent climate and how it must have changed in the past. -
A Stratigraphic Section That Traverses the Noachian-Hesperian Capturing Diverse Habitable Environments
42nd Lunar and Planetary Science Conference (2011) 2355.pdf A STRATIGRAPHIC SECTION THAT TRAVERSES THE NOACHIAN-HESPERIAN CAPTURING DIVERSE HABITABLE ENVIRONMENTS. J. F. Mustard1 and B. L. Ehlmann1, 1Department of Geological Sciences, Box 1846, Brown University, Providence, RI 02912 [email protected]. Introduction: The evolution of distinct eras on enigmatic unit. It generally lies in local topographic Mars defined by specific hydrous mineral phases as lows, though it is observed to drape underlying topog- proposed by [1] provides a broad framework for as- raphy defined by the basement. In some places the sessing the nature of habitable environments and the spectroscopic signature is definitively olivine-bearing interaction of water with the crust and surface through [5, 6], while others the olivine signatures are supple- time. If processes on early Mars that resulted in altera- mented by absorptions diagnostic of magnesite [7]. In tion mineralogies dominated by phyllosilicate were a few regions serpentine is also detected in association followed by processes resulting in sulfate and other with olivine [8]. In the study region this unit is almost evaporite minerals during the middle period of Mars’ exclusively magnesite-bearing. Where well exposed it then it will be critical to identify and understand re- typically shows an irregular polygonal fracturing on gions of the crust that record these transitions. These the scale of meters. The olivine-magnesite unit is localities will capture a fundamental reorganization of commonly capped by a medium-toned spectrally bland aqueous processes on a planetary scale. The region of unit that preserves impact craters. The thickness of the the western Isidis Basin that transitions to the volcanic two units is on the order of several 10s of meters. -
Durham Research Online
Durham Research Online Deposited in DRO: 27 March 2019 Version of attached le: Published Version Peer-review status of attached le: Peer-reviewed Citation for published item: Orgel, Csilla and Hauber, Ernst and Gasselt, Stephan and Reiss, Dennis and Johnsson, Andreas and Ramsdale, Jason D. and Smith, Isaac and Swirad, Zuzanna M. and S¡ejourn¡e,Antoine and Wilson, Jack T. and Balme, Matthew R. and Conway, Susan J. and Costard, Francois and Eke, Vince R. and Gallagher, Colman and Kereszturi, Akos¡ and L osiak, Anna and Massey, Richard J. and Platz, Thomas and Skinner, James A. and Teodoro, Luis F. A. (2019) 'Grid mapping the Northern Plains of Mars : a new overview of recent water and icerelated landforms in Acidalia Planitia.', Journal of geophysical research : planets., 124 (2). pp. 454-482. Further information on publisher's website: https://doi.org/10.1029/2018JE005664 Publisher's copyright statement: Orgel, Csilla, Hauber, Ernst, Gasselt, Stephan, Reiss, Dennis, Johnsson, Andreas, Ramsdale, Jason D., Smith, Isaac, Swirad, Zuzanna M., S¡ejourn¡e,Antoine, Wilson, Jack T., Balme, Matthew R., Conway, Susan J., Costard, Francois, Eke, Vince R., Gallagher, Colman, Kereszturi, Akos,¡ L osiak, Anna, Massey, Richard J., Platz, Thomas, Skinner, James A. Teodoro, Luis F. A. (2019). Grid Mapping the Northern Plains of Mars: A New Overview of Recent Water and IceRelated Landforms in Acidalia Planitia. Journal of Geophysical Research: Planets 124(2): 454-482. 10.1029/2018JE005664. To view the published open abstract, go to https://doi.org/ and enter the DOI. Additional information: Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. -
North American Stratigraphic Code1
NORTH AMERICAN STRATIGRAPHIC CODE1 North American Commission on Stratigraphic Nomenclature FOREWORD TO THE REVISED EDITION FOREWORD TO THE 1983 CODE By design, the North American Stratigraphic Code is The 1983 Code of recommended procedures for clas- meant to be an evolving document, one that requires change sifying and naming stratigraphic and related units was pre- as the field of earth science evolves. The revisions to the pared during a four-year period, by and for North American Code that are included in this 2005 edition encompass a earth scientists, under the auspices of the North American broad spectrum of changes, ranging from a complete revision Commission on Stratigraphic Nomenclature. It represents of the section on Biostratigraphic Units (Articles 48 to 54), the thought and work of scores of persons, and thousands of several wording changes to Article 58 and its remarks con- hours of writing and editing. Opportunities to participate in cerning Allostratigraphic Units, updating of Article 4 to in- and review the work have been provided throughout its corporate changes in publishing methods over the last two development, as cited in the Preamble, to a degree unprece- decades, and a variety of minor wording changes to improve dented during preparation of earlier codes. clarity and self-consistency between different sections of the Publication of the International Stratigraphic Guide in Code. In addition, Figures 1, 4, 5, and 6, as well as Tables 1 1976 made evident some insufficiencies of the American and Tables 2 have been modified. Most of the changes Stratigraphic Codes of 1961 and 1970. The Commission adopted in this revision arose from Notes 60, 63, and 64 of considered whether to discard our codes, patch them over, the Commission, all of which were published in the AAPG or rewrite them fully, and chose the last. -
Lithostratigraphic Units
INTEGRATED STRATIGRAPHY Amalia Spina Amalia Spina, PhD. Office: Palazzina di Geologia, Second floor Tel. 0755852696 E-mail: [email protected] - Principles of stratigraphy - The time in stratigraphy; geological chronology (relative and absolute) the temporal sequence of events; standard global chronostratigraphical scale. Comparison between the stratigraphic scales in marine and continental successions. - Stratigraphic units standard (definition and principle): law of superimposition, principle of original horizontality, of lateral continuity and of biotic succession, the Stratigraphic Code. - The sedimentary cyclicity - Lithostratigraphy - Magnetostratigraphy - Biostratigraphy - Chemostratigraphy - Cronostratigraphy and geochronology - Astronomic cyclostratigraphy - Sequence stratigraphy - Palaeogeographic reconstructions. Prerequisites: In order to better comprehend the main topics of integrated stratigraphy, the students that follow this course must have: - knowledge of the fundamentals of geology; - knowledge of the sedimentary rocks (classification); - knowledge of the principle of stratigraphy; - knowledge of the principle of palaeontology; - knowledge of the principle of sedimentology; These preconditions are important for attending and not attending students. Written test: it consist of the solution of multiple choice test and graphic /practical exercises. The number of questions ranges between 15 and 30 on the basis of the difficulty.The test has a duration of no more than 80 minutes. The goal of the test is to verify the knowledge acquired on the course contents in order to ensure that the student learned the principles of integrated stratigraphy and its main applications. To complete the evaluation the test also consists on the discussion of a case study proposed by the Professor carried out individually or in small groups (max three students).It consists to discuss the stratigraphic features of a certain geological area and the implications for the subsurface hydrocarbon exploitation.