Earth's Story

Earth's Story

Question: the idea that geologic processes occurring now are the same as those in the past
Answer: uniformitarianism

Question: the idea that geologic change happens suddenly
Answer: catastrophism

Question: the study of past life using fossils
Answer: paleontology

Question: a scientist who outlined uniformitarianism in 1788
Answer: James Hutton

Question: a scientist who published "Principles of Geology" from 1830-1833
Answer: Charles Lyell

Relative Dating

Question: the idea that younger rocks lie on top of older rocks
Answer: superposition

Question: the process of figuring out if an object is older or younger than another
Answer: relative dating

Question: a break in the geologic record
Answer: unconformity

Question: the process of wearing down
Answer: erosion

Question: a missing layer of rock
Answer: unconformity

Absolute Dating

Question: the process of figuring out how old (in years) an object is
Answer: absolute dating

Question: the most common method of absolute dating
Answer: radiometric dating

Question: method that dates rocks older than 100,000 years old
Answer: potassium-argon method

Question: the time it takes for one-half of a radioactive sample to decay
Answer: half-life

Question: unstable isotopes
Answer: radioactive

Mixed Bag

Question: According to uniformitarianism, geologic change happens _____________.
Answer: gradually

Question: What is an example of a catastrophe?
Answer: EQ, volcano, asteroid hitting Earth

Question: How are rock layers arranged in the geologic column?
Answer: oldest rocks are on the bottom

Question: Define fault.
Answer: a break in Earth's crust

Question: What is the most common type of unconformity?
Answer: disconformity


Question: Define isotope.
Answer: atoms with the same number of protons but different number of neutrons

Question: Name one method of radiometric dating used for rocks more than 10 million years old.
Answer: uranium-leadrubidium-strontium

Question: What does a scientist need to know to figure out the absolute age of a rock?
Answer: the rate of decay for a radioactive element in the rock

Question: Name 2 index fossils
Answer: graptolitetrilobite

Question: Name the 4 criteria needed for all index fossils
Answer: uniquewidespreadlived a short period of timeabundant