Fossil Formation and Classification Flashcards
These are the preserved remains of organisms from earlier periods of Earth’s history.
Fossil
Some organisms have spaces in their bodies, it involves groundwater filling up these spaces.
Permineralization
This happens when organisms leave behind the residual carbon while other elements are shed off.
Carbonization
involves the minerals in organisms’ bodies being replaced by other minerals.
Replacement
form when substances like minerals or sediments press over the body of a dead organism
Mold Fossils
are formed when sediments and minerals fill up the body cavities of an organism.
Cast Fossils
are traces left behind by organisms in the past. examples are fossilized animal tracks, eggs, and coprolites.
Trace Fossils
are entire organisms whose bodies have been preserved.
True Form Fossils
the methods involve estimating sequences of events. This usually involves sequencing rock layers through stratigraphy.
Relative Dating
involves sequencing rocks.
stratigraphy
give a numerical estimate of the age of rock layers and fossils.
Absolute Dating
An example is radiometric dating, which involves radioactive decay.
Absolute Dating
One of the most commonly-used radioactive isotopes in dating fossils in absolute dating is
carbon-14 which has a half-life of 5 730 years.
The time it takes for 14C to radioactively decay is described by its half-life. C has a half-life of 5,730 years. In other words, after 5,730 years, only half of the original amount of 14C remains in a sample of organic material. Then it changes to
N - 14 or Nitorgen 14
are useful in giving information about the time when the organism was alive compared to other fossils.
Index fossils
