Earth's Story and Those Who First Listened
The number of years of Earth's history that scientists study.
What is 4.6 billion years?
The process which involves the comparison of rock layers with others in a sequence to determine its age.
What is relative dating?
What is the uranium-lead method?
What is a mold fossil?
This is the largest division of geologic time.
What is an eon?
What would marine fossils discovered on a Canadian mountaintop tell scientists?
What is rocks on the mountaintop were once below the ocean's surface?
Erosion is one of the major causes of the missing rock layers, known as
What are unconformities?
The process that always occurs at a constant rate in which absolute dating in based.
What is radioactive decay?
The type of fossil used to date surrounding rock layers.
What is an index fossil?
This era ended with the largest mass extinction in Earth's History.
What is the Paleozoic Era?
This is the idea that geologic change happens rapidly.
What is catastrophism?
What is superposition?
Scientists need to know this to figure out the absolute age of a rock.
What is the rate of decay for a radioactive element in the rock?
Scientists use fossilized animal tracks to tell certain things about the animals.
What are size, direction, how many are traveling together and speed?
Scientists believe this may have caused the extinction of the dinosaurs.
What is climate change?
The study of past life.
This is what we call the slanting of rock layers.
What is tilting?
What is radioactive isotopes break down into stable isotopes of other elements?
Scientists can learn this from studying the relationships between fossils.
What is how life has changed?
What is to divide Earth's history into manageable parts?
The idea that geologic processes occurring now are the same as those in the past.
What is uniformitarianism?
The most common type of unconformity.
What is a disconformity?
The time needed for half of a sample of a radioactive substance to undergo radioactive decay.
What is half-life?
A mark left by a dinosaur's tail.
What is a trace fossil?
This is the era in which birds and small mammals began to evolve.
What is the Mesozoic era?