Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
remaining cards
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

fossils and unconfor

Absolute Age The exact age of a rock or fossils
Angular unconformity When there is movement of the earth that turns the rock layers at an angle.
Anticline An upward fold of rock
Crosscutting Intrusive magma or lava is always younger than the existing rock.
Elastic limit the amount of heat and pressure rock can withstand before breaking.
Extrusion Lava that hardens on the surface
Folding When heat and pressure bends a rock
Fossils The preserved remains or traces of an organism
index fossils Useful fossils that help determine the age of other fossils or rock layers. They must 1) have lived and died in a relatively short period of time and 2) They need to be widely distributed.
Intrusion Magma cooled and hardened into a mass of igneous rock.
Lava Flow from the mantle that is on top of the crust
Law of Inclusion When rock layers have bits of the rock layer below it, it must be younger than the one below it.
Magma Flow from the mantle that is inside the crust
Relative Dating Determining the relative age of rock layers or order of past geologic events
Relative Age The approximate age of a rock layer or fossil
Syncline A downward fold of rock
Strata Rock layers
The Law of Superposition In an undisturbed horizontal sequence of rocks, the oldest rock layers will be on the bottom.
Unconformity represent gaps in the geologic record; periods of time that are not represented by any rocks.