DOCSLIB.ORG

Legacy Image

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Legacy Image National Aeronautics and Space Administration Planetary Geology in the 1980s NASA SP - 467 Planetary Geology in the 1980s Joseph Veverka Cornell University Prepared for NASA Office of Space Science and Applications Scientific and Technical Information Branch 1985 NASA National Pieronautics and Space Administration Washington, DC Planetary Geology Working Group (PGWG) (1981-1982) Joseph Boyce Dag Nummedal NASA Headquarters, Dept. of Geology Code EL Louisiana State University Washington, DC 20546 Baton Rouge, LA 70803 Michael Carr Stephen Saunders USGS Jet Propulsion Laboratory, MS 345 Middlefield Road 183150 Menlo Park, CA 94025 4800 Oak Grove Drive Pasadena, CA 91103 Mark Cintala Dept. of Geological Sciences Eugene Shoemaker Brown University USGS Providence, RI 02912 2255 North Gemini Drive Flagstaff, AZ 86001 Merton E. Davies RAND Corporation Robert Strom 1700 Main Street University of Arizona Santa Monica, CA 90406 Lunar and Planetary Laboratory Tucson, AZ 85721 Everett Gibson Code TN7 Joseph Veverka, Chairman Johnson Space Center 312 Space Sciences Houston, TX 77058 Cornell University Ithaca, NY 14853 Ronald Greeley Arizona State University Donald Wise Dept. of Geology Dept. of Geology Tem~e.. AZ 85821 University of Massachusetts ~mherst,MA 01002 Kenneth Hamblin Brigham Young University Geology Department Provo, Utah 84602 Library of Congress Cataloging in Publication Data Main entry under title: Planetary geology in the 1980s. (NASA SP ; 467) Includes bibliographical rcfbrenccs. 1. Planets-Geology. I. i'cvrrka, .Joseph. 11. Series. QB603.G46P55 1988 559.9 88-1 6350 For sale by the National Technical Information Service, Springfield, VA 22151 Acknowledgments The original version of this report was written between 1981 and 1982 by members of the Planetary Geology Working Group with much advice and some participation from our colleagues. While the report represents a group effort, special thanks are due to the following individuals for drafting the original versions of the chapters or sections indicated: M. Carr and R. Greeley (Chapter 1); D. Wise (Section 2.1); M. Carr (Section 2.2); M. Cintala and J. Head (Section 2.3); R. Greeley (Section 2.4); D. Nummedal and V. Baker (Section 2.5); V. Hamblin (Section 2.6); R. Greeley (Section 2.7); R. Strom and E. Shoemaker (Chapter 3); E. Gibson and F. Fanale (Chapter 4); S. Saunders and J. Head (Chapter 5); M. Davies (Chapter 6). J. Veverka Preface This is the third document in a chronological series. The first appeared in 1970 at the request of NASA's former Planetology Program under the title, "A Strategy for Geologic Exploration of the Planets," edited by M. H. Carr and published as United States Geological Survey Circular No. 640. Then, as now, the objectives were to define the major goals of planetary geology and to set forth methods of meeting these goals. In 1976, the Carr study was updat- ed with the publication of A Geologzcal Basis for the Exploration of the Planets, edited by R. Greeley and M. H. Carr (NASA SP-417). The purpose of the present report is to once more provide an update and a future projection, this time into the 1980s. The basic objectives of the original strategy laid out in 1970 and in 1976 have changed little. Rather, it is our approach to realizing these goals that has matured and expanded. Now that Voyager has ventured beyond the asteroid belt into the realm of the outer planets, we have become keenly aware that the detailed study of satellites can teach us much about the geologic evolution of solid bodies in general. When the 1976 report was written, the bizarre nature of Titan's surface was hardly suspected; we were not aware of the intense volcanic activity of 10, or of the possibility that Neptune's Triton may have an ocean of liquid nitrogen. Another new emphasis that will be found in this report concerns the developing perception that the investigation of small bodies-asteroids, comets, and small satellites-can reveal much about the processes that were important during the earliest stages of the solar system's history. The en- hanced emphasis on satellites and small bodies does not imply that our traditional interest in the geology of Earthlike planets has de- creased; rather, it is a sign that as our discipline grows we are able vii to assimilate more and more diverse information in building a truer picture of the geologic evolution of the planets. We certainly expect that the 1980s will see a continuation of the vigorous effort to decipher the complex geologic history of Mars revealed by the Viking data. We also anticipate that as the quality of our geologic information concerning Venus continues to improve, a major goal of planetary geology research will be to understand the distinct evolutionary paths of Earth and Venus-two planets which at first sight appear to be similar in many of their bulk physical properties. As before, this report is not concerned with advocating any particular spacecraft mission, or series of missions, nor does it outline a sequence of solar system exploration programs. Rather, it is restricted to defining the kinds of experiments, observations, and measurements that need be made by Ear~h-based,Earth-orbit, and spacecraft exploration techniques to address major issues of con- cern to planetary geology. It also discusses important goals of data analysis and data synthesis in the area of planetary geology. This document was written by the Planetary Geology Working Group during 1981-1982. The Group attempted to produce a consensus document based on drafts of individual chapters and sections written by specific members (the individual contributions are identified in the Ac- knowledgments). We also received numerous comments on several draft versions of the report from many of our colleagues; we hope that this helpful criticism has enabled us to maintain a balanced and a represen- tative perspective throughout this document. J. Veverka .. Vlll Table of Contents 1. Introduction .......................................................................... 1.1 Relevance of Planetary Geology .................................... 1.1.1. Origin and Evolution of the Solar System ........ 1.1.2. Origin and Evolution of Life ............................. 1.1.3. Our Terrestrial Environment ............................ 1.2 The Planetary Geology Approach .................................. 1.2.1. Present Geologic State ...................................... 1.2.2. Geological Evolution of Planets ........................ 1.3 Comparative Planetology ............................................... 2 . Surface Features and Processes ............................................ Structural Geology and Tectonics ................................. 2.1.1. Basic Questions ................................................. 2.1.2. Geologic Maps ................................................... 2.1.3. Experimental Stress/Strain Studies ................... 2.1.4. Stress Field Indicators ....................................... 2.1.5. Tectonic Energy and the Generation of Stress Fields .............................................................. 2.1.6. Methodology ...................................................... 2.1.7. Summary ............................................................ 2.2 Volcanism ....................................................................... 2.2.1. Geomorphology of Volcanic Landforms ........... 2.2.2. Modeling of Volcanic Processes ........................ 2.2.3. Experimental Petrology ..................................... 2.2.4. Summary ............................................................ 2.3 Cratering ......................................................................... 28 2.3.1. Impact Cratering: An Introduction ................... 28 2.3.2. Methods of Study .............................................. 30 2.3.3. Craters in Geologic Studies: Some Established and Emerging Uses ........................................ 32 2.3.4. Persistent Problems and Unanswered Questions ....................................................... 34 2.3.5. Summary ............................................................ 36 2.4 Eolian Processes ............................................................. 36 2.4.1. Review of Eolian Activity on the Planets .......... 37 2.4.2. Relevance of Eolian Studies to Planetary Geology .......................................................... 41 2.4.3. Suggested Approach for Investigating Eolian Processes ........................................................ 46 2.4.4. Summary ............................................................ 47 2.5 Fluvial Processes ............................................................. 49 2.5.1. Water as a Geologic Agent ................................ 49 2.5.2. Dynamics of Fluvial Sedimentation ................... 50 2.5.3. Channel and Valley Morphology on Mars ........ 53 2.5.4. Summary ............................................................ 59 2.6 Mass Movement .............................................................. 59 2.6.1. Mass Movement on Earth .................................. 60 2.6.2. Mass Movement on the Moon and Mercury ..... 61 2.6.3. Mass Movement on Mars ................................... 61 2.6.4. Mass Movement on Other Bodies ..................... 62 2.6.5. Summary ............................................................ 63 2.7 Glacial and Periglacial Processes ................................... 64 2.7.1. Physical Properties of Water Ice of Interest to Geology .........................................................
Load more

Recommended publications
  • Washington Division of Geology and Earth Resources Open File Report
    l 122 EARTHQUAKES AND SEISMOLOGY - LEGAL ASPECTS OPEN FILE REPORT 92-2 EARTHQUAKES AND Ludwin, R. S.; Malone, S. D.; Crosson, R. EARTHQUAKES AND SEISMOLOGY - LEGAL S.; Qamar, A. I., 1991, Washington SEISMOLOGY - 1946 EVENT ASPECTS eanhquak:es, 1985. Clague, J. J., 1989, Research on eanh- Ludwin, R. S.; Qamar, A. I., 1991, Reeval­ Perkins, J. B.; Moy, Kenneth, 1989, Llabil­ quak:e-induced ground failures in south­ uation of the 19th century Washington ity of local government for earthquake western British Columbia [abstract). and Oregon eanhquake catalog using hazards and losses-A guide to the law Evans, S. G., 1989, The 1946 Mount Colo­ original accounts-The moderate sized and its impacts in the States of Califor­ nel Foster rock avalanches and auoci­ earthquake of May l, 1882 [abstract). nia, Alaska, Utah, and Washington; ated displacement wave, Vancouver Is­ Final repon. Maley, Richard, 1986, Strong motion accel­ land, British Columbia. erograph stations in Oregon and Wash­ Hasegawa, H. S.; Rogers, G. C., 1978, EARTHQUAKES AND ington (April 1986). Appendix C Quantification of the magnitude 7.3, SEISMOLOGY - NETWORKS Malone, S. D., 1991, The HAWK seismic British Columbia earthquake of June 23, AND CATALOGS data acquisition and analysis system 1946. [abstract). Berg, J. W., Jr.; Baker, C. D., 1963, Oregon Hodgson, E. A., 1946, British Columbia eanhquak:es, 1841 through 1958 [ab­ Milne, W. G., 1953, Seismological investi­ earthquake, June 23, 1946. gations in British Columbia (abstract). stract). Hodgson, J. H.; Milne, W. G., 1951, Direc­ Chan, W.W., 1988, Network and array anal­ Munro, P. S.; Halliday, R. J.; Shannon, W.
    [Show full text]
  • View of Theoretical Approaches 51
    University of Alberta Caribou Hunting at Ice Patches: Seasonal Mobility and Long-term Land-Use in the Southwest Yukon By Vandy E. Bowyer A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Anthropology © Vandy E. Bowyer Spring 2011 Edmonton, Alberta Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission. In memory of Tagish ABSTRACT Recently documented ice patch sites in the southwest Yukon are ideal for evaluating precontact hunter-gatherer land-use patterns in the western subarctic. Located in the alpine of the mountainous regions of the boreal forest, ice patches are associated with well preserved hunting equipment, caribou (Rangifer tarandus) dung and an abundance of faunal remains dating to over 8000 years ago. However, current models are inadequate for explaining caribou hunting at ice patches as they tend to emphasize large-scale communal hunts associated with latitudinal movements of caribou. Much less is known about the alititudinal movment of caribou and the associated hunting forays to ice patches in the alpine.
    [Show full text]
  • Mission to Jupiter
    This book attempts to convey the creativity, Project A History of the Galileo Jupiter: To Mission The Galileo mission to Jupiter explored leadership, and vision that were necessary for the an exciting new frontier, had a major impact mission’s success. It is a book about dedicated people on planetary science, and provided invaluable and their scientific and engineering achievements. lessons for the design of spacecraft. This The Galileo mission faced many significant problems. mission amassed so many scientific firsts and Some of the most brilliant accomplishments and key discoveries that it can truly be called one of “work-arounds” of the Galileo staff occurred the most impressive feats of exploration of the precisely when these challenges arose. Throughout 20th century. In the words of John Casani, the the mission, engineers and scientists found ways to original project manager of the mission, “Galileo keep the spacecraft operational from a distance of was a way of demonstrating . just what U.S. nearly half a billion miles, enabling one of the most technology was capable of doing.” An engineer impressive voyages of scientific discovery. on the Galileo team expressed more personal * * * * * sentiments when she said, “I had never been a Michael Meltzer is an environmental part of something with such great scope . To scientist who has been writing about science know that the whole world was watching and and technology for nearly 30 years. His books hoping with us that this would work. We were and articles have investigated topics that include doing something for all mankind.” designing solar houses, preventing pollution in When Galileo lifted off from Kennedy electroplating shops, catching salmon with sonar and Space Center on 18 October 1989, it began an radar, and developing a sensor for examining Space interplanetary voyage that took it to Venus, to Michael Meltzer Michael Shuttle engines.
    [Show full text]
  • Primitive Bodies Panel Planetary Science Decadal Survey Space Studies Board National Research Council
    Space Studies Board Mailing Address: 500 Fifth Street, NW Washington, DC 20001 www.nationalacademies.org Primitive Bodies Panel Planetary Science Decadal Survey Space Studies Board National Research Council National Academy of Sciences Building 2101 Constitution Ave. NW, Washington, D.C. (Entrance at 2100 C Street NW) Conference Room 150 FINAL AGENDA1 September 9-11, 2009 Wednesday, September 9, 2009 CLOSED SESSION 7:30 a.m. Room Opens (Breakfast available in the meeting room) 8:30 a.m. Welcome and Agenda Review Joseph Veverka 8:45 a.m. Overview of NRC Study Process Dwayne Day 9:15 a.m. Balance and Composition Discussion Dwayne Day 10:00 a.m. Break OPEN SESSION2 10:15 a.m. Decadal Survey Overview Steven Squyres Cornell University 11:00 a.m. Lessons Learned from the 2003 Decadal Survey Dale Cruikshank NASA Ames Research Center 11:45 a.m. Committee Discussion (Lunch will be served in the meeting room, committee discussion will continue) 12:45 p.m. Charge to the Decadal Survey James Green/Lindley Johnson NASA Headquarters 1 Updated September 8, 2009 2 Webcast at http://nasa-nai.acrobat.com/primitive1/, Audio at 866-606-4717, Access Code 6686308. This meeting is being held to gather information to help the committee conduct its activities. The committee will examine the information and material obtained during open sessions in an effort to inform its work. Although opinions may be stated and lively discussion may ensue, no conclusions are being drawn at this time. Therefore, observers who draw conclusions about the committee's work based on today's discussions will be doing so prematurely.
    [Show full text]
  • Placing World War I in the History of Mathematics David Aubin, Catherine Goldstein
    Placing World War I in the History of Mathematics David Aubin, Catherine Goldstein To cite this version: David Aubin, Catherine Goldstein. Placing World War I in the History of Mathematics. 2013. hal- 00830121v1 HAL Id: hal-00830121 https://hal.sorbonne-universite.fr/hal-00830121v1 Preprint submitted on 4 Jun 2013 (v1), last revised 8 Jul 2014 (v2) HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Placing World War I in the History of Mathematics David Aubin and Catherine Goldstein Abstract. In the historical literature, opposite conclusions were drawn about the impact of the First World War on mathematics. In this chapter, the case is made that the war was an important event for the history of mathematics. We show that although mathematicians' experience of the war was extremely varied, its impact was decisive on the life of a great number of them. We present an overview of some uses of mathematics in war and of the development of mathematics during the war. We conclude by arguing that the war also was a crucial factor in the institutional modernization of mathematics. Les vrais adversaires, dans la guerre d'aujourd'hui, ce sont les professeurs de math´ematiques`aleur table, les physiciens et les chimistes dans leur laboratoire.
    [Show full text]
  • The History Group's Silver Jubilee
    History of Meteorology and Physical Oceanography Special Interest Group Newsletter 1, 2010 ANNUAL REPORT CONTENTS We asked in the last two newsletters if you Annual Report ........................................... 1 thought the History Group should hold an Committee members ................................ 2 Annual General Meeting. There is nothing in Mrs Jean Ludlam ...................................... 2 the By-Law s or Standing Orders of the Royal Meteorological Society that requires the The 2010 Summer Meeting ..................... 3 Group to hold one, nor does Charity Law Report of meeting on 18 November .......... 4 require one. Which papers have been cited? .............. 10 Don’t try this at home! ............................. 10 Only one person responded, and that was in More Richard Gregory reminiscences ..... 11 passing during a telephone conversation about something else. He was in favour of Storm warnings for seafarers: Part 2 ....... 13 holding an AGM but only slightly so. He Swedish storm warnings ......................... 17 expressed the view that an AGM provides an Rikitea meteorological station ................. 19 opportunity to put forward ideas for the More on the D-Day forecast .................... 20 Group’s committee to consider. Recent publications ................................ 21 As there has been so little response, the Did you know? ........................................ 22 Group’s committee has decided that there will Date for your diary .................................. 23 not be an AGM this year. Historic picture ........................................ 23 2009 members of the Group ................... 24 CHAIRMAN’S REVIEW OF 2009 by Malcolm Walker year. Sadly, however, two people who have supported the Group for many years died during I begin as I did last year. Without an enthusiastic 2009. David Limbert passed away on 3 M a y, and conscientious committee, there would be no and Jean Ludlam died in October (see page 2).
    [Show full text]
  • Martian Crater Morphology
    ANALYSIS OF THE DEPTH-DIAMETER RELATIONSHIP OF MARTIAN CRATERS A Capstone Experience Thesis Presented by Jared Howenstine Completion Date: May 2006 Approved By: Professor M. Darby Dyar, Astronomy Professor Christopher Condit, Geology Professor Judith Young, Astronomy Abstract Title: Analysis of the Depth-Diameter Relationship of Martian Craters Author: Jared Howenstine, Astronomy Approved By: Judith Young, Astronomy Approved By: M. Darby Dyar, Astronomy Approved By: Christopher Condit, Geology CE Type: Departmental Honors Project Using a gridded version of maritan topography with the computer program Gridview, this project studied the depth-diameter relationship of martian impact craters. The work encompasses 361 profiles of impacts with diameters larger than 15 kilometers and is a continuation of work that was started at the Lunar and Planetary Institute in Houston, Texas under the guidance of Dr. Walter S. Keifer. Using the most ‘pristine,’ or deepest craters in the data a depth-diameter relationship was determined: d = 0.610D 0.327 , where d is the depth of the crater and D is the diameter of the crater, both in kilometers. This relationship can then be used to estimate the theoretical depth of any impact radius, and therefore can be used to estimate the pristine shape of the crater. With a depth-diameter ratio for a particular crater, the measured depth can then be compared to this theoretical value and an estimate of the amount of material within the crater, or fill, can then be calculated. The data includes 140 named impact craters, 3 basins, and 218 other impacts. The named data encompasses all named impact structures of greater than 100 kilometers in diameter.
    [Show full text]
  • Production and Saturation of Porosity in the Lunar Highlands from Impact Cratering
    The fractured Moon: Production and saturation of porosity in the lunar highlands from impact cratering The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Soderblom, Jason M., et al. “The Fractured Moon: Production and Saturation of Porosity in the Lunar Highlands from Impact Cratering.” Geophysical Research Letters, vol. 42, no. 17, Sept. 2015, pp. 6939–44. © 2015 American Geophysical Union As Published http://dx.doi.org/10.1002/2015GL065022 Publisher American Geophysical Union (AGU) Version Final published version Citable link http://hdl.handle.net/1721.1/118615 Terms of Use Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. PUBLICATIONS Geophysical Research Letters RESEARCH LETTER The fractured Moon: Production and saturation 10.1002/2015GL065022 of porosity in the lunar highlands Key Points: from impact cratering • The relation between impact-generated porosity and crater size is quantified Jason M. Soderblom1, Alexander J. Evans2, Brandon C. Johnson1, H. Jay Melosh3, Katarina Miljković1,4, • Impacts into highly porous targets 5 6 7 8 3 result in positive gravity anomalies Roger J. Phillips , Jeffrey C. Andrews-Hanna , Carver J. Bierson , James W. Head III , Colleen Milbury , 9 7 1 2,10 11 • The cratering record of the oldest Gregory A. Neumann , Francis Nimmo , David E. Smith , Sean C. Solomon , Michael M. Sori , lunar surfaces is preserved in the
    [Show full text]
  • VHSL Regionals 2012 Round #4
    VHSL Regionals 2012 Round 4 First Period, Fifteen Tossups 1. This author tells of an attack "by three doors left unguarded" as "blue-eyed banditti" climb into his chair. This poet, who immortalized his daughters Alice, Allegra, and Edith in "The Children's Hour," also wrote a long poem set "by the shores of Gitche Gumee." In another poem, he described a character who feels "the secret dread of the lonely belfry and the dead" before sending a signal from the Old North Church. For 10 points, name this American poet of The Song of Hiawatha and "Paul Revere's Ride." ANSWER: Henry Wadsworth Longfellow 105-12-55-04101 2. One side in this incident, led by Yellow Bird and Big Foot, was urged to resist because their shirts would protect them from gunfire. The other side in this event was led by James Forsyth. Eighty-three years after this event occurred, Russell Means of the AIM led a seventy-one-day standoff with federal agents at the site of this incident. This event occurred days after Sitting Bull was killed in reaction to the popularity of the Ghost Dance. For 10 points, name this 1890 massacre of about 150 Sioux in South Dakota. ANSWER: Wounded Knee Massacre 131-12-55-04102 3. While living near the town of Templeton, this character clashes with Judge Marmaduke Temple and befriends the young hunter Oliver Edwards. In another novel, this character guides Cora and Alice Munro to their father’s command and kills Magua to avenge the death of his friend Uncas.
    [Show full text]
  • The Planetary Report
    A Publication of THEPLANETA SOCIETY o o o • o -e o o Board of Directors CARL SAGAN NORMAN R. AUGUSTI NE President Chairman and CEO, Director, Martin Marietta Corporation Laboratory for Planetary Studies, Cornelf University JOHN E. BRYSON Chairman and CEO, BRUCE MURRAY Southern California Edison Vice President Professor of Planetary Science, JOSEPH RYAN California Institute of Technology O'Melveny & Myers LOU IS FRIEDMAN STEVEN SPI ELBERG A WARNING FROM YOUR EDITOR Bringing People Together Through Executive Director director and producer You may soon be getting a phone call Planetary Science-Page 13-Education Board of Advisors from me. No, I won't be asking you for has always been close to the hearts of DIANE ACKERMAN JOHN M. LOGSDON donations or nagging you about a missed Planetary Society members, and we have poet and author Director, Space Policy Institute, George Washington University deadline (a common fear among planetary sponsored many programs to promote sci­ BUZZ ALDRIN Apollo 11 astronaut HANS MARK scientists). Instead, I will be asking for ence education around the world. We've The University of Texas at Austin RICHARD BERENDZEN your opinion about The Planetary Report. gathered together reports on three projects educator and astrophysicist JAMES MICHENER author JACQUES BLAMONT Each month our computer will randomly now completed and one just beginning. Chief Scientist, Centre MARVIN MINSKY Nationa! d'Etudes Spatia/es, Toshiba Professor of Media Arts select several members whom I will call to A Planetary Readers' Service-Page 16- France and Sciences, Massachusetts Institute of Technology discuss the contents of our latest issue-or For most of its history, the science we call RAY BRADBURY poet and author PHILIP MORRISON any other topic related to our publications.
    [Show full text]
  • Cold-Climate Landform Patterns in the Sudetes. Effects of Lithology, Relief and Glacial History
    ACTA UNIVERSITATIS CAROLINAE 2000 GEOGRAPHICA, XXXV, SUPPLEMENTUM, PAG. 185–210 Cold-climate landform patterns in the Sudetes. Effects of lithology, relief and glacial history ANDRZEJ TRACZYK, PIOTR MIGOŃ University of Wrocław, Department of Geography, Wrocław, Poland ABSTRACT The Sudetes have the whole range of landforms and deposits, traditionally described as periglacial. These include blockfields and blockslopes, frost-riven cliffs, tors and cryoplanation terraces, solifluction mantles, rock glaciers, talus slopes and patterned ground and loess covers. This paper examines the influence, which lithology and structure, inherited relief and time may have had on their development. It appears that different rock types support different associations of cold climate landforms. Rock glaciers, blockfields and blockstreams develop on massive, well-jointed rocks. Cryogenic terraces, rock steps, patterned ground and heterogenic solifluction mantles are typical for most metamorphic rocks. No distinctive landforms occur on rocks breaking down through microgelivation. The variety of slope form is largely inherited from pre- Pleistocene times and includes convex-concave, stepped, pediment-like, gravitational rectilinear and concave free face-talus slopes. In spite of ubiquitous solifluction and permafrost creep no uniform characteristic ‘periglacial’ slope profile has been created. Mid-Pleistocene trimline has been identified on nunataks in the formerly glaciated part of the Sudetes and in their foreland. Hence it is proposed that rock-cut periglacial relief of the Sudetes is the cumulative effect of many successive cold periods during the Pleistocene and the last glacial period alone was of relatively minor importance. By contrast, slope cover deposits are usually of the Last Glacial age. Key words: cold-climate landforms, the Sudetes 1.
    [Show full text]
  • Chenangoforks2.Pdf
    • Rilles – Lunar Rilles are long, narrow, depressions formed by lava flows, resembling channels. • Rugged Terra – Rugged terra are mountainous regions of the moon. • Wrinkle Ridges – Wrinkle Ridges are created through compression of tectonic plates within the maria. • Graben – Graben are formed from the stress of two fault lines. • Scarps – A displacement of land beside a fault. • Fault – A fault is a fracture on the surface. Grabens Rilles Scarps Fault Rugged Terra Wrinkle Ridge •Scarp‐ A type of fault. It is the displacement of land alongside a fault. • Mare Ridge‐ The raised edges of a mare impact basin. •Trough‐ A depression that is characterized by its shallow ridges • Lineament‐ A linear expression used to characterize a fault lined valley •The wrinkle ridge structures that deform and interrupt the mare basalts are commonly asymmetrical, with the steeper side bounded by a complex scarp composed of multiple overlapping lobate scarp segments that may have rounded crests that make them resemble mare ridges. •Lobate scarps are thrust faults that occur primarily in the Moon's lunar highlands. •a graben is a depressed block of land bordered by parallel faults. •Graben is German for ditch. •A graben is the result of a block of land being downthrown producing a valley with a distinct scarp on each side. •Graben often occur side-by-side with horsts. Horst and graben structures are indicative of tensional forces and crustal stretching. •Horsts are parallel blocks that remain between graben, the bounding faults of a horst typically dip away from the center line of the horst. •Also known as a Dark halo craterlets •Dark-halo craters are formed when an impact unearths lower albedo material from below the surface, then deposits this darker ejecta around the main crater.
    [Show full text]