Catalogue of Meteorites from South America

ACEVEDO, R.D.; ROCCA, M.; GARCÍA, VÍCTOR MANUEL

Springer Verlag

Lugar: Dordretch; Año: 2014 p. 147

978-3-319-01924-6

Today, it is clear that the interplanetary space between the planets of our Solar System is not a perfect void. Millions of small bodies are present there orbiting our Sun together with the large objects. If the small bodies are bigger than 100 m in diameter and they are composed of rocks and/or metals then they are called as asteroids. If they are integrated by ice then they are called comets. If they are smaller than 100 m in diameter then they are called meteoroids. In many cases, their orbits cross the orbit of our planet so they can get in direct contact with our atmosphere. When a meteoroid enters in our atmosphere and survives as far as to reach to the Earth?s surface it is called a meteorite. So meteorites are small solid masses coming from the interplanetary space between the planets. Meteorites are at present the most important and numerous sources of extraterrestrial rock or metal samples for the planetary scientific research. They may come from fragments ejected from the surfaces of asteroids in collisions between asteroids themselves, and they may also be a pieces ejected in large impact events on the surface of our Moon and in the surfaces of nearby planets like Mars and Venus. Meteorites are very old objects (4,600 to 4,000 Ma on average) so they are important to understand the events connected with the origin of our Solar System. They also teach us about the exotic geology and geochemistry of all these extraterrestrial bodies. The names of meteorites are founded after the places where they are fallen or found, and they are classified into three wide categories and some subcategories. Stony meteorites are composed mostly of mafic silicate minerals. There are two types: chondrites (primitive meteorites, with chondrules) and achondrites (differentiate meteorites, without chondrules). Stony-iron meteorites have approximately equal quantities of metal and silicates. They comprise the pallasites and mesosiderites. Iron meteorites are especially metal. They are classified into twelve major groups depending on their relative amounts of iron, nickel, and certain trace elements. R.