Geological Time
What is the dominant species currently?
What is the name of the man who created these laws/principles?
Nicolas Steno
What is a fossil?
Yes! We all have C-14 in our bodies.
Can fossils be found in igneous rock?
No! The fossils would melt!
Principle of Original Horizontally says that sediment is deposited in ________ layers.
Horizontal layers. Looks like: <-------------> remember, FLAT! :)
Your teacher hands you original remains, what are you holding?
Original remains are bones/teeth/insects in amber
What is 1 limitation of C-14?
It has to be once a living thing. No carbon dating ghosts!
What is the law that says: OLDEST at the bottom and YOUNGEST at the top?
Principle of Superposition
extends in ALL directions until it thins out
Principle of Lateral Continuity
Someone in your class asks you: "Hey dude, what are replaced remains?" What do you tell them?
Replaced remains are formed when all biological matter (bio=life) is replaced with minerals
What is a half life? (Hint: not years)
A half life is how long it takes for 1/2 (half) of a radioactive substance to remain.
What is relative age dating? (Think: exact date or around a certain time)
Tells you when something is formed in relation to other events. Does NOT tell you how long ago.
This principle says: rock (igneous) intrusion must be YOUNGER than rest of other rocks
Cross Cutting
What is a trace fossil?
INDIRECT evidence of past life such as tracks, burrows, bite marks
The parent is the STARTING isotope and the daughter is the DECAYED isotope.
What does absolute age dating mean?
Tells you when something formed in exact units like days, months, or years.
Ex: fossil was formed 1.5 billion years ago
This principle states: sediment is deposited in horizontal <---------------> layers and that any TILT or CHANGE happens after deposit
Principle of Original Horizontality
How are index fossils used?
Index fossils are remains of an organism that lived in a certain time. Scientists use them to determine how old something is
What is another limitation of using C-14?
It can only date back 70,000 years!