''Traces of Catastrophe: A Handbook of Shock-Metamorphic Effects in Terrestrial Meteorite Impact Structures'' is a book written by Bevan M. French of the

Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded ...

. It is a comprehensive technical reference on the science of

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...

s. It was published in 1998 by the

Lunar and Planetary Institute The Lunar and Planetary Institute (LPI) 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 (USRA) and is sup ...

(LPI), which is part of the

Universities Space Research Association The Universities Space Research Association (USRA) was incorporated on March 12, 1969, in Washington, D.C. as a private, nonprofit corporation under the auspices of the National Academy of Sciences (NAS). Institutional membership in the asso ...

(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 (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. ...

for the e-book download, or

planar deformation features Planar deformation features, or PDFs, are optically recognizable microscopic features in grains of silicate minerals (usually quartz or feldspar), consisting of very narrow planes of glassy material arranged in parallel sets that have distinct orie ...

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 The Earth Impact Database is a database of confirmed impact structures or craters on Earth. It was initiated in 1955 by the Dominion Observatory, Ottawa, under the direction of Carlyle S. Beals. Since 2001, it has been maintained as a not-for-pr ...

lists it among the suggested reading on its introductory page about impact craters. The

Impact Field Studies Group The Impact Field Studies Group (IFSG) was 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 invo ...

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."

Overview

The book is divided into chapters listed below. Chapter 1 introduces

s, now recognized on Earth due to the study of other planetary bodies, most significantly the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

. 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 An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

and

comets A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...

. Historical impacts are discussed, including the

Tunguska event The Tunguska event (occasionally also called the Tunguska incident) was an approximately 12- megaton explosion that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of June 3 ...

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 Complex commonly refers to: * Complexity, the behaviour of a system whose components interact in multiple ways so possible interactions are difficult to describe ** Complex system, a system composed of many components which may interact with each ...

craters, and

multi-ring basins A multi-ringed basin (also a multi-ring impact basin) is not a simple bowl-shaped crater, or a peak ring crater, but one containing multiple concentric topographic rings; a multi-ringed basin could be described as a massive impact crater, surrou ...

. Then it covers the

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is dis ...

processes that continue after the crater has been made. Chapter 4 is about

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 metamorp ...

, the unique changes made to rocks by the extreme but brief shock forces of an impact. The effects include

shatter cones Shatter cones are rare geological features that are only known to form in the bedrock beneath meteorite impact craters or underground nuclear explosions. They are evidence that the rock has been subjected to a shock with pressures in the ra ...

, 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 Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of ...

tion to vaporization of the rocks and later condensation into glass. Chapter 5 surveys various

impactite Impactite is rock created or modified by one or more impacts of a meteorite. Impactites are considered metamorphic rock, because their source materials were modified by the heat and pressure of the impact. On Earth, impactites consist primarily o ...

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 An ejecta blanket is a generally symmetrical apron of ejecta that surrounds an impact crater; it is layered thickly at the crater's rim and thin to discontinuous at the blanket's outer edge. The impact cratering is one of the basic surface format ...

pseudotachylite Pseudotachylyte (sometimes written as pseudotachylite) is an extremely fine-grained to glassy, dark, cohesive rock occurring as veinsTrouw, R.A.J., C.W. Passchier, and D.J. Wiersma (2010) ''Atlas of Mylonites- and related microstructures.'' Sprin ...

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 Tektites (from grc, τηκτός , meaning 'molten') are gravel-sized bodies composed of black, green, brown or grey natural glass formed from terrestrial debris ejected during meteorite impacts. The term was coined by Austrian geologist Franz ...

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.

Notes

References

External links

''Traces of Catastrophe''
e-book download at

''Traces of Catastrophe''
entry at NASA Technical Reports Server {{Impact cratering on Earth Impact geology Geology books Astronomy books