Traces of Catastrophe
Encyclopedia
The book Traces of Catastrophe: A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures, or more commonly shortened to Traces of Catastrophe, was written by Bevan M. French of the Smithsonian Institution
. It is a comprehensive technical reference on the science of impact crater
s. It was published in 1998 by the Lunar and Planetary Institute
(LPI), which is part of the Universities Space Research Association
(USRA). It was originally available in hard copy from LPI, but is now only available as a portable document format (PDF)This page uses the term PDF to mean either Portable Document Format
for the e-book download, or planar deformation features
for geological evidence of impact shock. e-book free download.
The book has become very influential in the field of impact crater research, appearing as a common reference for papers and web sites on the topic. The Earth Impact Database
lists it among the suggested reading on its introductory page about impact craters. The Impact Field Studies Group
Impact Database says it is required reading before submitting an observation of a proposed impact site. NASA's Goddard Space Flight Center (GSFC) lists it among general references relevant to Planetary Science
across the solar system. NASA GSFC also has a Remote Sensing Tutorial site which calls Traces of Catastrophe an "exceptional summary of impact cratering."
Chapter 1 introduces impact crater
s, now recognized on Earth due to the study of other planetary bodies, most significantly the Moon
. On Earth, impact craters differ from other processes in geology in being rare, from a release of extremely large amounts of energy, and happening in an instant. It contrasts with other geological forces that mostly take very long periods of time.
Chapter 2 covers the astronomical aspect with asteroids and comets. Historical impacts are discussed, including the Tunguska event
of 1908. There is a table comparing effects from tiny to enormous meteor impacts.
Chapter 3 is about the process of formation of a crater during an impact event
. The propagation of the shock wave leads to progressive stages of contact/compression, excavation and modification. It differentiates simple and complex
craters, and multi-ring basins. Then it covers the erosion
processes that continue after the crater has been made.
Chapter 4 is about shock metamorphism
, the unique changes made to rocks by the extreme but brief shock forces of an impact. The effects include shatter cones, planar deformation features (PDFs)
, selective melting and many others. The amount of shock metamorphism in the rocks progresses in stages with the amount of pressure that they were exposed to, ranging from fracturing and breccia
tion to vaporization of the rocks and later condensation into glass.
Chapter 5 surveys various impactite
s, meaning shock-metamorphosed rocks, and where they are found in an impact structure based on the pressures in various parts of the cratering process. The topics include crater-fill breccias, ejecta blanket
, pseudotachylite
and impact melt breccias.
Chapter 6 covers impact melts, their volume relative to crater size, melt rocks in the crater, impact melt breccias, dikes & sills, and tektite
s.
Chapter 7 is about finding new impact structures. It includes search methods and verification using unique features of craters covered earlier.
Chapter 8 looks to the future, considers current problems and subjects for further study.
An appendix "Criteria for recognizing terrestrial impact structures" provides a checklist for use in verification of potential impact sites.
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
. It is a comprehensive technical reference on the science of impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
s. It was published in 1998 by the Lunar and Planetary Institute
Lunar and Planetary Institute
The Lunar and Planetary Institute is a scientific research institute dedicated to study of the solar system, its formation, evolution, and current state. The Institute is part of the Universities Space Research Association and is supported by the Science Mission Directorate of the National...
(LPI), which is part of the Universities Space Research Association
Universities Space Research Association
The Universities Space Research Association was incorporated on March 12, 1969 in the District of Columbia as a private, nonprofit corporation under the auspices of the National Academy of Sciences . Institutional membership in the Association has grown from 49 colleges and universities when it was...
(USRA). It was originally available in hard copy from LPI, but is now only available as a portable document format (PDF)This page uses the term PDF to mean either Portable Document Format
Portable Document Format
Portable Document Format is an open standard for document exchange. This file format, created by Adobe Systems in 1993, is used for representing documents in a manner independent of application software, hardware, and operating systems....
for the e-book download, or planar deformation features
Planar deformation features
Planar deformation features, or PDFs, are optically recognizable microscopic features in grains of silicate minerals , consisting of very narrow planes of glassy material arranged in parallel sets that have distinct orientations with respect to the grain's crystal structure.PDFs are only produced...
for geological evidence of impact shock. e-book free download.
The book has become very influential in the field of impact crater research, appearing as a common reference for papers and web sites on the topic. The Earth Impact Database
Earth Impact Database
The Earth Impact Database is the authoritative source for information on confirmed impact structures or craters on Earth. It was initiated in 1955 by the Dominion Observatory, Ottawa, under the direction of Dr. Carlyle S. Beals...
lists it among the suggested reading on its introductory page about impact craters. The Impact Field Studies Group
Impact Field Studies Group
The Impact Field Studies Group is a scientific organization emphasizing geologic field research of suspected and confirmed sites of impact craters and impact structures. The group is composed of researchers, professionals and students involved in study of impact sites...
Impact Database says it is required reading before submitting an observation of a proposed impact site. NASA's Goddard Space Flight Center (GSFC) lists it among general references relevant to Planetary Science
Planetary science
Planetary science is the scientific study of planets , moons, and planetary systems, in particular those of the Solar System and the processes that form them. It studies objects ranging in size from micrometeoroids to gas giants, aiming to determine their composition, dynamics, formation,...
across the solar system. NASA GSFC also has a Remote Sensing Tutorial site which calls Traces of Catastrophe an "exceptional summary of impact cratering."
Overview
The book is divided into chapters listed below.Chapter 1 introduces impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
s, now recognized on Earth due to the study of other planetary bodies, most significantly the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
. On Earth, impact craters differ from other processes in geology in being rare, from a release of extremely large amounts of energy, and happening in an instant. It contrasts with other geological forces that mostly take very long periods of time.
Chapter 2 covers the astronomical aspect with asteroids and comets. Historical impacts are discussed, including the Tunguska event
Tunguska event
The Tunguska event, or Tunguska blast or Tunguska explosion, was an enormously powerful explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, at about 7:14 a.m...
of 1908. There is a table comparing effects from tiny to enormous meteor impacts.
Chapter 3 is about the process of formation of a crater during an impact event
Impact event
An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...
. The propagation of the shock wave leads to progressive stages of contact/compression, excavation and modification. It differentiates simple and complex
Complex crater
Complex craters are a type of large impact crater morphology.Above a certain threshold size, which varies with planetary gravity, the collapse and modification of the transient cavity is much more extensive, and the resulting structure is called a complex crater...
craters, and multi-ring basins. Then it covers the erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
processes that continue after the crater has been made.
Chapter 4 is about shock metamorphism
Shock metamorphism
Shock metamorphism or impact metamorphism describes the effects of shock-wave related deformation and heating during impact events. The formation of similar features during explosive volcanism is generally discounted due to the lack of metamorphic effects unequivocally associated with explosions...
, the unique changes made to rocks by the extreme but brief shock forces of an impact. The effects include shatter cones, planar deformation features (PDFs)
Planar deformation features
Planar deformation features, or PDFs, are optically recognizable microscopic features in grains of silicate minerals , consisting of very narrow planes of glassy material arranged in parallel sets that have distinct orientations with respect to the grain's crystal structure.PDFs are only produced...
, selective melting and many others. The amount of shock metamorphism in the rocks progresses in stages with the amount of pressure that they were exposed to, ranging from fracturing and breccia
Breccia
Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....
tion to vaporization of the rocks and later condensation into glass.
Chapter 5 surveys various impactite
Impactite
Impactite is an informal term describing a rock created or modified by the impact of a meteorite. The term encompasses shock-metamorphosed target rocks, melts and mixtures of the two, as well as sedimentary rocks with significant impact-derived components .-Some localities:*Nördlinger Ries...
s, meaning shock-metamorphosed rocks, and where they are found in an impact structure based on the pressures in various parts of the cratering process. The topics include crater-fill breccias, ejecta blanket
Ejecta blanket
An ejecta blanket is a generally symmetrical apron of ejecta that surrounds crater; it is layered thickly at the crater’s rim and thin to discontinuous at the blanket’s outer edge....
, pseudotachylite
Pseudotachylite
Pseudotachylite is a fault rock that has the appearance of the basaltic glass, tachylyte. It is dark in color and has a glassy appearance. However, the glass has normally been completely devitrified into very fine-grained material with radial and concentric clusters of crystals...
and impact melt breccias.
Chapter 6 covers impact melts, their volume relative to crater size, melt rocks in the crater, impact melt breccias, dikes & sills, and tektite
Tektite
Tektites are natural glass rocks up to a few centimeters in size, which most scientists argue were formed by the impact of large meteorites on Earth's surface. Tektites are typically black or olive-green, and their shape varies from rounded to irregular.Tektites are among the "driest" rocks, with...
s.
Chapter 7 is about finding new impact structures. It includes search methods and verification using unique features of craters covered earlier.
Chapter 8 looks to the future, considers current problems and subjects for further study.
An appendix "Criteria for recognizing terrestrial impact structures" provides a checklist for use in verification of potential impact sites.
External links
- Traces of Catastrophe e-book download at Lunar and Planetary InstituteLunar and Planetary InstituteThe Lunar and Planetary Institute is a scientific research institute dedicated to study of the solar system, its formation, evolution, and current state. The Institute is part of the Universities Space Research Association and is supported by the Science Mission Directorate of the National...
- Traces of Catastrophe entry at NASA Technical Reports Server