List 2 Flashcards
Absolute Age
The numeric age of an object or event.
Carbon 14
A radioactive isotope of carbon used to find the ages of human artifacts or things that were once living.
Carbon Dating
A scientific method used to determine the age of an artifact.
Cast Fossil
A fossil that is a copy of an organisms shape, formed when minerals seep into a mold.
Cenozoic Era
“Age of mammals”
Eon
The largest division in geological time.
Era
A particular period in history; a sub division of eons.
Fault
A break in the earths crust.
Fossil
The preserved remains of an organism that lived in the past.
Geological time scale
A record of the geological events and life forms in earths history.
Half Life
The length of time required for half of the radioactive atoms in a sample to decay.
Ice Core
A cylinder of ice drilled from an ice sheet that can help tell the climates of the past.
Igneous Rock
A type of rock that forms from the cooling of molten rock at or below the surface.
Index fossil
A fossil known to have lived in a particular geological age that can be used to date the rock layer in which its found.
Law of Superposition
The top rock layer is the youngest and the bottom rock layer is the oldest.
Mesozoic Era
“Age of reptiles and dinosaurs”
Metamorphic Rock
A type of rock that forms from an existing rock that is changed by heat, pressure, or chemical reactions.
Mold Fossil
A space in a rock that has the shape of the remains of a living thing that once occupied that space.
Paleozoic Era
“Age of Ancient Life”
Petrified wood
A stone fossil of a tree
Preserved Remains
Remains of organisms in tar, amber, or ice
Radioactive Dating
A technique used to determine the actual age of a fossil on the basis of the amount of a radioactive element it contains
Relative Age
The age of a rock compared to the ages of rock layers
Sedimentary Rock
A type of rock that forms when particles from other rocks or the remains of plants and animals are pressed and cemented together
