100-C 25-C 50-C 75-C C+M 50-C+M C+Y 50-C+Y M+Y 50-M+Y 100-M 25-M 50-M 75-M 100-Y 25-Y 50-Y 75-Y 100-K 25-K 25-19-19 50-K50-40-40 75-K 75-64-64

CHAPTER 13

Meteorites

Michael E. Lipschutz

Purdue University

West Lafayette, Indiana

Ludolf Schultz

Max-Planck-Institut f ̈ur Chemie,

Mainz, Germany

1. Introduction 5. Chemical and Isotopic Constituents of Meteorites


2. Meteorite Classification 6. Meteorite Chronometry


3. Meteorites of Asteroidal Origin and Their Parent Bodies Bibliography


4. Meteorites from Larger Bodies

M

eteorites, the “Poor Man’s Space Probe,” are impor-
tant because they contain the oldest solar system
materials for research and sample a wide range of par-
ent body—exteriors and interiors—some primitive, some
highly evolved. Meteorites record certain solar and galac-
tic effects and yield otherwise unobtainable data relevant
to the genesis, evolution, and composition of the Earth,
other major planets, satellites, asteroids, and the Sun. Some
contain inclusions created before solar system formation;
others contain organic matter produced on grain bound-
aries in the early nebula and/or in giant interstellar clouds.
Meteorites also constitute important “ground truth” in a
chemical and physical sense, critical to interpreting plan-
etary data obtained by remote sensing. Most importantly,
meteorites are on Earth, available for laboratory study by
the simplest to the most sophisticated analytical techniques.
If one picture is worth 10,000 words, then one sample is
worth 10,000 pictures. Even though meteorites are only
tiny source-fragments, proper integration of data from them
can better describe their sources, just as a more complete
mosaic can be deduced from a few tesserae.

∗Actual meteriorite (chondrite) dust is embedded in the stamp reproduced above. The stamp was issued by the Austrian postal service in 2006.

1. Introduction

1.1 General

In the Western world, 1492 marked the discovery of the

New World by the Old, the Spanish Expulsion, and, the old-

est documented, preserved, and scientifically studied me-

teoritefall—a 127 kg (LL6) stone that fell at Ensisheim in

Alsace. [A meteorite is named for the nearest post office or

geographic feature. The chemical-petrologic classification

is the scheme by which Ensisheim, for example, is clas-

sified as an LL6 chondrite (see Section 1.2).] The oldest

preserved meteorite fall might be Nogata (Japan), an L6,

which allegedly fell in 861 (but all associated documenta-

tion is more recent) and is in a Shinto shrine there. Recov-

ered meteorites, whose fall was unobserved, arefinds, some

having been discovered (occasionally artificially reworked)

in archaeological excavations in such Old World locations

as Ur, Egypt, and Poland, and in New World burial sites.

Obviously, prehistoric and early historic man recognized

meteorites as unusual, even venerable, objects.

Encyclopedia of the Solar System 2e©C2007 by Academic Press. All rights of reproduction in any form reserved. 251