Who developed the current system used to classify meteorites?
Prior (1920) and Mason (1967)
Why do we classify meteorites?
To communicate their different attributes
To recognize the associated implications
What is it called when a meteorite can be connected to an observed fall event?
Fall
What is it called when a meteorite cannot be connected to an observed fall event?
Find
Which type of meteorite is more prone to chemical interaction with terrestrial environments: falls or finds?
Finds
How is a meteorite named?
Location
Year found
Observation order
What is a chondrite?
An undifferentiated meteorite.
What is an achondrite?
A differentiated meteorite.
Name 3 characteristics common to chondrites.
They contain small (1-2mm) chondrules.
They have a solar-like composition.
They are derived from asteroids or comets that did not undergo planetary differentiation.
Name 2 commonly found achondrites.
Igneous rock melts
Breccias from differentiated origins
What is a class?
Two or more groups sharing primary whole-rock chemical and O-isotopic properties.
What are the 3 primary classes of meteorites?
Carbonaceous (C)
Ordinary (O)
Enstatite (E)
What are the 4 primary clans of meteorites?
CR
CM-CO
CV-CK
CI
What is a group?
A minimum of 5 unpaired chondrites of closely similar petrologic, whole-rock chemical, and O-isotopic characteristics.
Name the 8 C-chondrite groups.
CI
CM
CO
CV
CK
CR
CB
CH
Name the 3 O-chondrite groups in order from highest to lowest amount of iron (Fe).
H
L
LL
Name the 2 E-chondrite groups in order from highest to lowest amount of iron (Fe).
EH
EL
When is a subgroup defined?
When there are lesser petrologic differences among members of the same group.
What is a primitive achondrite?
A meteorite that has a primitive chemical affinity to the chondrite that it was formed from, but with a texture suggesting differentiation (e.g. molten, melt residue, extreme recrystallization).
What 4 processes do achondrite textures suggest?
Melting
Partial melting
Melt residue
Extreme recrystallization
What are the 4 classic core groups of primitive achondrites?
Acapulcoites
Lodranites
Winonaites
Silicate-bearing IAB & IIICD irons
Where do achondrites most often come from?
Differentiated asteroids, Mars, and the Moon
True or False: Achondrite group names are indicative of a common parent body.
False
Author
mermasia
ID
126856
Card Set
Intro to Meteorites
Description
Information found in the Weisberg et. al. paper on terminology and classification of meteorites.