fossils Flashcards
what is a fossil?
preserved evidence of ancient life
what types of fossils are there?
body fossils
trace fossils
what are body fossils?
any body parts such as bone, teeth, skin
what are trace fossils?
evidence of their day-to-day activities such as footprints, borrows, trails
how are fossils madde?
an organisms can become a fossil as long as it is protected from processes that may destroy the remains
how depositional environments create fossils?
high spots wear down low spots fill up
sediemnts are buried and turn to rock
how depositional environments create fossils?
high spots wear down low spots fill up
sediments are buried and turn to rock
sediments bury organisms and protect them from destruction
how does rate of burial affect a fossil?
the faster it is buried the more likely it is to become a fossil
why is rapid burial important?
takes away oxygen so it can’t decompose
no chance for other organisms to scavenge it
what happens once an organism is buried?
chemical changes take place that change it into a fossil
what is the most common way to fossilize something?
burial
what are ways to fossilize something?
freeze
mummify
encasement
replacement
permineralization
petrification
recrystallization
carbonization
Molds and cast
which methods are the best for having unaltered remains?
frozen
mummified
encased
what can something be encased in?
tar
amber
how do you get altered remains?
fossilization due to chemical reactions that change the composition
what happens when something is going through replacement?
original material is dissolved and another material takes its place
-shape is the same but composition is not
what happens when permineralization occurs?
water flows through pores and deposits minerals
what happens when petrification occurs?
permineralization and replacement
what happens when recrystallization occurs?
change the crystal or make it bigger
often makes a new mineral
what happens when carbonization occurs?
bury it and squeeze all water and volatiles out until only a carbon film is left
what is a mold?
the organism is stamped into sediment then removed to create a hole
