Fossils
What are fossils?
Preserved remains, impressions or traces of once-living organisms
Magma that flows onto the surface.
Lava
determines the specific age of rocks or fossils that contrasts with relative dating, which only indicates whether something is older or younger in comparison to something else.
Absolute Dating
Name three examples of trace fossils.
feathers, burrows, nests, coprolites
What is the half life of Carbon -14?
5730
A footprint or feather are examples of
Trace Fossils
What states the oldest rock layers are found at the bottom, and the youngest layers are at the top?
Law of Superposition
What is radioactive called
Carbon-14
Bones and Teeth are examples of
Body Fossils
What type of rock forms when magma or lava hardens?
Igneous
Rapid burial, absence of oxygen, mineral rich enviornment and protection from disturbance are examples of?
Fossilization
Lava that hardens on the outside is called an
Extrusion
When the number of neutrons varies, the atom becomes an
Isotope
Fossil that has a hollow space on one side and a raised form on the other
Mold and Cast Fossils
What method do geologists use to find the absolute ages of rocks?
Radioactive Dating
The most common type of fossilization is
Permineralization
Magma that pushes into bodies of rock and hardens beneath the surface.
Intrusion
When an organism dies, it stops absorbing what?
Carbon-14
What do fossils help scientists understand?
How organisms have evolved and changed over millions of years.
A gap in the geological record formed when sedimentary rocks cover an eroded surface is called a
Unconformity
How do fossils help scientists understand evolutionary history?
By showing changes in organisms over time. Fossils show what the Earth’s environment was like in the past. They provide evidence of past climate patterns.
Common elements used in radioactive dating:
Carbon, Potassium and Uranium
Radioactivity occurs due to an __________ of neutrons in the nucleus.
Excess
What type of fossil preserves soft tissues in rare cases?
Body Fossils
If there are 2,000 g of Carbon-14 how long will it take to decay to 500g?
11,460 yrs