R. T. Correlation Half Life Vocabulary

Which era takes up the most amount of time

Precambrian

Name a species of trilobite

Elliptocephala, cryptolithhus or phacops

Which was first to evolve, birds or mammals

mammals

Lead is the stable product of the radioactive decay of which element

Uranium

A certain species of dinosaur grew from 15 ft to a height of 25 ft over 3 years. What is its rate of change? Round to nearest tenth and label.

3.3 ft/yr

Give the specific names of two types of rock correlation

Fossil correlation, walking the outcrop, rock similarities

Give the two qualities of a good index fossil

Wide horizontal, short vertical, or lived everywhere for a short time

Name three features that are always younger than the rock they are in

Fold, fault, tilt, joint, intrusion

Name the two geologic principles used to relative age rock

Principle of horizonality and superposition

How can you tell an extrusion from an intrusion

Extrusions do not have contact metamorphism on all sides

Which is the only isotope for once living things

Carbon 14

How many grams of the original 50 g of C14 would be left after 34,200 years

.78 grams

How many original grams of C14 were there if 4 are left after 22,800 years

64 g

How old is rock if it has undergone two half lives of K 40

9 2.6 x 10

What percent of a radioactive substance is left after 4 half lives

6.25%

Define uniformitarianism

Present is the key to the past

Define outcrop

Exposed bedrock

Define orogeny

Period of mountain building

Give the four steps for making an unconformity

Uplift, erosion, subsidence, deposition

What must a species do in order to survive

Adapt or produce variations