everything Flashcards
What is a fossil
Either the organism itself or an imprint of some part of it
What is the process of becoming a fossil
taphonomy (what happened to the fossil from death to discovery
What is Burial
if a body is quickly buried or protected by gravel, sand, or volcanic ash
What is fossilization/miniralization
replacement of an organism itself or an imprint molecule by molecule with inorganic materials
What are the two main categories fossil dating methods
relative and chronometric
Stratigraphic
sequential layering of deposits, relative, what is higher and lower in layers of rock (relative)
Biostratigraphy
when a fossil is found next to another organism whose date is better known (relative)
Lithostratigraphy
different types of rock layers define time (relative)
Tephrostratigraphy
What comes from volcanos (relative)
Magnetostratigraphy/paleomagneticism/geomagnetic polarity
the magnetic pole reverses every several hundred thousand years. iron compounds align differently in a rock depending on polarity (relative)
Fluorine dating
Used on bone-if two bones are put down at the same time in the same environment they will absorb the same amount of fluorine (relative)
Dendrochronology
tree ring dating; matching a tree to a master plot
isotopic/radiometric
radioactive isotopes break down over time, so do at a geometric rate. half lives are at regular intervals (chronometric)
potassium/argon dating
indirect method used on volcanic ash, half life of 1.3 billion years. optimal range: 10,000-4.5 billion years ago. Use after 400,000 years ago (chronometric)
Carbon 14/ radiocarbon dating
dates organic material such as bone. half life: 5740 + or - 40 years. range: a few 100- 40,000 years ago.
