Sketch of Widmanstatten pattern, see the glossary for more information. Meteorites of Michigan – Page 1 of 20 Geological Survey ILLUSTRATIONS Bulletin 5 Frontispiece. Photograph of September 17, 1966 fireball. ......4 METEORITES OF MICHIGAN Figure 1. Region of observation of December 1965 fireball ....4 Figure 2. Train of December 1965 fireball...............................5 by Figure 3. Train of December 1965 fireball...............................5 VON DEL CHAMBERLAIN Figure 4. Trajectory of December 1965 fireball .......................6 Astronomer Figure 5. Orbit of December 1965 meteorite...........................6 Abrams Planetarium Figure 6. Observations of September 1966 fireball.................6 Michigan State University Figure 7. High velocity projectiles............................................9 Illustrated by James M. Campbell Figure 8. Cross section of stony meteorite............................10 Michigan Department of Conservation Figure 9. Stony-iron meteorite...............................................10 Lansing, 1968 Figure 10. Section of Central Missouri iron meteorite ...........11 Figure 11. Allegan meteorite .................................................14 Figure 12. Grand Rapids meteorite .......................................14 CONTENTS Figure. 13. Iron River meteorite.............................................15 ABSTRACT .....................................................................2 Figure 14. Kalkaska meteorite...............................................15 GLOSSARY.....................................................................2 Figure 15. Reed City meteorite .............................................16 FOREWORD...................................................................3 Figure 16. Rose City meteorite..............................................17 I. FIRE IN THE SKY ........................................................3 Figure 17. Seneca Township meteorite.................................18 Fireball of December 1965. ..................................................3 UNNUMBERED FIGURES Fireball of September 1966. .................................................5 Painting of a fireball..................................................................7 Other Fireballs......................................................................7 High velocity aluminum cone.. ...............................................18 A Fiery Journey. ...................................................................7 Disintegrating graphite projectile............................................18 II. KINDS OF METEORITES...........................................8 Barringer Meteorite Crater .....................................................19 Irons .....................................................................................9 Stones ..................................................................................9 Front Cover. Sketch of Widmanstatten pattern.(see page 9.) .1 Stony-irons ...........................................................................9 Back Cover. Sketch of shock waves of a meteorite entering III. HOW TO IDENTIFY SPECIMENS.............................9 the earth’s atmosphere ..................................................19 Fusion Crust. ........................................................................9 Specific Gravity ..................................................................10 ABSTRACT Magnetism..........................................................................10 By way of introduction to the fascinating subject of Examining Interior ..............................................................10 meteorites, the author describes the dramatic sights and Test for Nickel ....................................................................10 sounds accompanying two recent spectacular fireballs in Chondrules. ........................................................................11 the Great Lakes region. The reader is also taken on an IV. MINERALOGY.........................................................11 imaginary journey with a meteorite in its fiery flight Irons ...................................................................................11 through the atmosphere. Stones ................................................................................12 Meteorites are among the rarest mineral objects found Stony-Irons .........................................................................12 on earth. Their meaning and how they are identified and classified are discussed. Details on eight specimens Mineral List .........................................................................12 found in Michigan are also provided. Many interesting V. DOCUMENTED FINDS AND FALLS IN MICHIGAN12 accounts by actual observers are related and Allegan ...............................................................................13 commented upon. Grand Rapids .....................................................................13 A convenient glossary of terms and a list of references Iron River............................................................................14 complete this booklet. Kalkaska.............................................................................14 Michigan Iron......................................................................15 GLOSSARY Reed City............................................................................15 Rose City............................................................................16 Mineral terms are defined in Mineralogy chapter. Seneca Township...............................................................16 ablation: Removal of material from a solid object through vaporization. VI. IN CONCLUSION . ..............................................18 achondrite: Type of stony meteorite lacking the FURTHER READING....................................................18 chondrules characteristic of most stony meteorites. HISTORICAL BRIEFS...................................................18 aerolite: Another name for stony meteorite. Meteorites of Michigan – Page 2 of 20 ataxite: An iron meteorite consisting of either pure Widmanstatten, who discovered them. kamacite, an irregular mixture of kamacite and taenite, or pure taenite. bolide: Exploding fireball. chondrite: Stony meteorite containing chondrules. chondrule: Small nearly spherical aggregate of the minerals olivine and/or pyroxene found in large numbers 1 in most stony meteorites. They are usually less than /8 inch in diameter. end-point: The point where a fireball disappears, often in a shower of "sparks". etch: To corrode a prepared surface with acid for the purpose of revealing structural details. FOREWORD fireball: Very bright meteor. This booklet explains the basic "why's" and "wherefore's" fusion crust: The outer covering of a meteorite produced of some of the most unique rock and mineral specimens by solidification of melted surface materials formed as a found on earth. Although intended primarily for persons meteorite passes through the atmosphere. having little acquaintance with meteorites, this hexahedrite: Iron meteorite consisting of large cubic information will interest most anyone who wonders how crystals of kamacite. these small astronomical bodies are identified, how they mesosiderite: Stony-iron meteorite, the stony portion of originated, and how many and what types have been which consists of the pyroxene and plagioclase minerals. reported in Michigan. Readers wishing to delve further meteor: The light phenomenon produced by a solid into the subject should consult the reading list in back. body moving very rapidly through the atmosphere. Those wishing to skip the short technical chapter on Popularly called a "shooting star". mineralogy may do so without loss of continuity. meteorite: A natural solid object from space that retains Meteorites are found by people, wherever people its identity after having landed on earth. The term is also happen to be. Although most anyone could find a used to refer to the object in space before colliding with "wanderer from the sky", the actual possibility is slight the earth. because these are among the rarest of all mineral objects. Our knowledge of them, therefore, depends to meteoriticist: Scientist who is a specialist in the study of a great extent upon the willingness of finders to make meteors and meteorites. specimens available for study and display. This book is octahedrite: Most common type of iron meteorite. dedicated to those individuals who have contributed to Contains bands of taenite and kamacite referred to as the finding and preserving of specimens in Michigan. Widmanstatten structure. Mr. Chamberlain is Acting Director in the Abrams octahedron: A solid geometric form having eight faces. Planetarium at Michigan State University. Meteors and pallasite: Stony-iron meteorite in which the stony portion meteorites have been a special concern of his for a consist of olivine. number of years. Since coming to Michigan he has path: The projection of the trajectory of a meteor or been particularly active in promoting a better fireball against the sky as seen by an observer. understanding of these extraordinary events, particularly as they relate to our own area. regmaglypts: Shallow depressions resembling thumbprints found on the surface of many meteorites produced by ablation as the meteorite passed through Gerald E. Eddy the atmosphere. Lansing State Geologist siderite: Another name for an iron meteorite. Nov. 1, 1967 Michigan Geological